Environment Protection and Biodiversity Conservation (Wildlife Conservation Plan for Seabirds) Instrument 2022

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Chapter 2 Seabirds of Australia

Seabirds are a taxonomically varied group of nearly 350 bird species (around

3.5 per cent of all birds) that depend on the marine environment for at least part of their life cycle (BirdLife International 2019). By convention, seabirds are defined as species in the families Phaethontidae (Tropicbirds), Hydrobatidae (Northern Storm-petrels), Oceanitidae (Austral Storm-petrels), Diomedeidae (Albatrosses), Procellariidae (Shearwaters and petrels), Spheniscidae (Penguins), Fregatidae (Frigatebirds), Sulidae (Gannets and boobies), Pelecanidae (Pelicans), Stercorariidae (Skuas) and Laridae (Gulls and terns). While seabirds vary greatly in their lifestyle and habitats, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental challenges and feeding niches have resulted in similar adaptations.

In general, seabirds are long lived, have delayed breeding and have fewer young than other birds do. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species undertake long migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be oceanic, coastal, or in some cases spend a part of the year away from the sea entirely.

Adaptation to the marine environment

Seabirds have evolved numerous adaptations to living on and feeding in the marine environment. The evolution of wing morphology of an individual species or family has been shaped by its ecological niche. Longer wings and low wing loading are typical of more oceanic species, while diving species have shorter wings (Gaston 2004). Species such as the Wandering Albatross (Diomedea exulans), which forage over large areas of ocean, have a reduced capacity for powered flight and are dependent on a type of gliding called dynamic soaring (where the wind deflected by waves provides lift) as well as slope soaring (Pennycuick 1982). Seabirds also almost always have webbed feet, to aid movement on the surface as well as assisting diving in some species.

The Procellariiformes are unusual among birds in having a strong sense of smell, which is used to find widely distributed food in a vast ocean (Lequette et al. 1989) and possibly to locate their colonies. Salt glands are used by seabirds to deal with the salt they ingest by drinking and feeding (particularly on crustaceans), and to help them osmoregulate (Harrison 1990). The excretions from these glands (which are positioned in the head of the birds, emerging from the nasal cavity) are almost pure sodium chloride.

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Diet and foraging behaviour

Seabirds have evolved to exploit different food resources in the world's oceans, and to a great extent, their physiology and behaviour have been shaped by their diet (Springer et al 2018). These evolutionary forces have often caused species in different families and even orders to evolve similar strategies and adaptations to the same problems, leading to remarkable convergent evolution, such as that between Northern Hemisphere auks and Southern Hemisphere penguins.

There are four basic feeding strategies, or ecological guilds, for feeding at sea: surface feeding, pursuit diving, plunge diving and kleptoparasitism; within these guilds there are multiple variations on the theme.

Many seabirds feed on the ocean's surface, as the action of marine currents often concentrates food such as krill, forage fish, squid or other prey items within reach of a dipped head. Surface feeders that swim often have unique bills adapted for their specific prey. Prions have special bills with filters called lamellae to filter out plankton from water (Brooke 2004), and many albatrosses and petrels have hooked bills to snatch fast-moving prey. Gulls have more generalised bills that reflect their more opportunistic lifestyle.

Pursuit diving exerts greater pressures (both evolutionary and physiological) on seabirds. Propulsion underwater can be provided by wings (as used by penguins, diving petrels and some other species of petrel) or feet (as used by cormorants). Many shearwaters are intermediate between the two, having longer wings than typical wing-propelled divers but heavier wing loadings than the other surface-feeding procellariids, leaving them capable of diving to considerable depths while still being efficient long-distance travellers (Shaffer et al. 2006). This is the dominant guild in polar and subpolar environments, as it is energetically inefficient in warmer waters. With their poor flying ability, many wing-propelled pursuit divers are more limited in their foraging range than other guilds, especially during the breeding season when young need regular feeding.

Gannets, boobies, tropicbirds and some terns engage in plunge diving, taking fast moving prey by diving into the water from flight. Plunge diving allows birds to use the energy from the momentum of the dive to combat natural buoyancy (caused by air trapped in plumage) (Ropert-Coudert et al. 2004), and thus uses less energy than the dedicated pursuit divers, allowing them to utilise more widely distributed food resources, for example, less productive tropical areas. Some plunge divers (as well as some surface feeders) are dependent on dolphins and tuna to push shoaling fish up towards the surface (Au et al. 1986).

Kleptoparasites are seabirds that steal food of other seabirds. Most famously, frigatebirds and skuas engage in this behaviour, although gulls, terns and other species will steal food opportunistically (Schreiber and Burger 2002). The nocturnal nesting behaviour of some seabirds has been interpreted as arising due to pressure from this aerial piracy (Gaston and Dechesne 1986). Kleptoparasitism is not thought to play a significant part of the diet of any species but is a supplement to food obtained by hunting (Schreiber and Burger 2002). A study of Great Frigatebirds stealing from Masked Boobies estimated that the frigatebirds could at most obtain 40 per cent of the food they needed, and on average obtained only 5 per cent (Vickery and Brooke 1994).

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Life history

Seabirds' life histories are largely different from those of land birds. In general, they are K-selected, that is, population numbers fluctuate at or near the carrying capacity of the environment in which they inhabit. K-selected species generally have a longer lifespan (up to 60 years), delay breeding for longer (for up to 10 years) and invest more effort into fewer young (Robertson 1993; Schreiber and Burger 2002). Most seabird species will only have one clutch a year, unless they lose the first, and many species (like the procellariids and sulids), only one egg a year (Schreiber and Burger 2002; Brooke 2004).

Care of young is protracted, extending for as long as six months, among the longest for birds. For example, frigatebirds have long periods of parental care with each chick fledging after four to six months and continued parental investment for up to 14 months (Metz and Schreiber 2002). Due to the extended period of care, breeding occurs every two years rather than annually for some species. This life-history strategy has likely evolved both in response to the challenges of living at sea (collecting widely scattered prey items), the frequency of breeding failures due to unfavourable marine conditions, and the relative lack of predation compared to that of land-living birds (Schreiber and Burger 2002).

Because of the greater investment in raising the young and because foraging for food may occur far from the nest site, both parents participate in caring for the young, and pairs are typically at least seasonally monogamous. Many species, such as gulls, shearwaters and penguins, retain the same mate for several seasons, and many petrel species can mate for life (Brooke 2004). Albatrosses and procellariids, which can mate for life, take many years to form a pair bond before they breed (Pickering and Berrow 2001; Brooke 2004).

Breeding

Seabird breeding colonies are highly variable. Individual nesting sites can be widely spaced, as in an albatross colony, or densely packed as with a tern colony. In most seabird colonies, several different species will nest on the same site, often exhibiting some niche separation. Seabirds can nest in trees or shrubs (if any are available), on the ground (with or without nests), on cliffs, in burrows under the ground and in rocky crevices. Competition can be strong both within species and between species, with aggressive species such as Sooty Terns pushing less-dominant species out of the most desirable nesting spaces (Schreiber et al. 2002). The Great-winged Petrel (Pterodroma macroptera) nests during the winter to avoid competition with the more aggressive species like the Flesh-footed Shearwater (Ardenna carneipes) in south-west Western Australia. When the seasons overlap, Flesh-footed Shearwaters will share burrows with young Great-winged Petrels in order to use their burrows for summer nesting (Serventy et al. 1971).

Many seabirds show remarkable site fidelity, returning to the same burrow, nest or site for many years, and they will defend that site from rivals with great vigour (Schreiber and Burger 2002). This behaviour increases breeding success, provides a place for returning mates to reunite, and reduces the costs of prospecting for a new site (Bried et al. 2003). Young adults breeding for the first time usually return to their natal colony, and often nest close to where they hatched. This tendency, known as philopatry, is so strong that a study of Laysan Albatrosses (Phoebastria immutabilis) found that the average distance between hatching site and the site where a bird established its own territory was 22 m (Fisher 1976). For some species, once these sites are lost, there are limited options for these species to “find” alternative locations and habitat. Given the gaps in seabird ecology, loss of these sites may pose a risk to certain seabird populations.

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Colonies are usually situated on islands, cliffs or headlands, which land mammals have difficulty accessing (Moors and Atkinson 1984). This is thought to provide protection to seabirds, which are often very clumsy on land. Colonies of breeding seabirds will also take advantage of artificial structures, breakwaters and offshore platforms. Breeding in colonies often arises in types of birds that do not defend feeding territories; this may be a reason why it arises more frequently in seabirds (Schreiber and Burger 2002). There are other possible advantages: colonies may act as information centres, where seabirds returning to the sea to forage can find out where prey is by studying returning individuals of the same species. There are disadvantages to colonial life, particularly the spread of disease and ectoparasites. Colonies also attract the attention of predators, principally other birds, and many species attend their colonies nocturnally to avoid predation (Keitt et al. 2004).

Migration

Like many birds, seabirds often migrate after the breeding season. Of these, the migration taken by the Arctic Tern (Sterna paradisaea) is the farthest of any

bird, crossing the equator in order to spend the Austral summer in Antarctica

(Egevang et al. 2010; Fijim et al. 2013). Other species also undertake trans-equatorial trips, both from the north to the south, and from south to north. The Sooty Shearwater (Ardenna grisea) undertakes an annual migration cycle that rivals that of the Arctic Tern; birds that nest in New Zealand and Chile spend the northern summer feeding in the North Pacific Ocean off Japan, Alaska and California, an annual round trip of 64,000 km (Shaffer et al. 2006).

Other species migrate shorter distances away from the breeding sites, their distribution at sea determined by the availability of food. If oceanic conditions are unsuitable, seabirds will immigrate to more productive areas, sometimes permanently if the bird is young (Oro et al. 2004). After fledging, juvenile birds often disperse further than adults, and to different areas, so are commonly sighted far from a species' normal range. Some species, such as some of the storm petrels, diving petrels and cormorants, rarely disperse at all, staying near their breeding colonies year-round.

Biologically important areas for seabirds in Australia

Australian Marine Parks (Commonwealth reserves proclaimed under the EPBC Act in 2007 and 2013) are located in Commonwealth waters that start at the outer edge of state and territory waters, generally three nautical miles (approximately 5.5 kilometres) from the shore, and extend to the outer boundary of Australia’s Exclusive Economic Zone (EEZ), 200 nautical miles (approximately 370 kilometres) from the shore. These marine parks have been established for the protection and conservation of biodiversity and other natural, cultural and heritage values of the parks. They contain biologically important areas for a range of protected seabird species, and management of these parks can contribute to the protection of these species, or the ecological processes that support them.

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Biologically important areas (BIAs) are areas that are particularly important for the conservation of the protected species and where aggregations of individuals display biologically important behaviour such as breeding, foraging, resting or migration.

BIAs were originally identified for some (but not all) seabirds through a rigorous and robust process as part of the Commonwealth Bioregional Planning Process and are referenced in Commonwealth Marine Bioregional Plans. The selection of BIAs for species was informed by the availability of scientific information, the conservation status of listed species and the importance of the region for the species. They represent areas where a specific behaviour is known to occur. The absence of an identified BIA does not mean that an area is not important habitat, just that it was not known at the time of assessment. This is because BIA maps reflect the best available information at the time of publication.

Specifically, BIAs are based on the following:

1. Behaviour (feeding, nesting, migration) occurs in the area;
2. Certainty of occurrence (only areas of ‘known’ or ‘likely’ occurrence are considered);
3. The level to which species use the BIA;
4. The season(s) during which species use the BIA; and
5. Source(s) of the information upon which the BIA is based.

Biologically important areas have been identified for a number of listed seabirds that occur in Commonwealth marine areas. Behaviours used to define biologically important areas for seabirds include breeding areas with a foraging buffer, and roosting habitats.

The BIA maps are a dynamic tool which allow for up-to-date information to be stored and referenced in a geospatial environment, building on information used to inform the wildlife conservation plan.

The range of species for which biologically important areas are identified will continue to expand as reliable spatial and scientific information becomes available. Biologically important areas are included in the Department’s Conservation Values Atlas (www.environment.gov.au/cva).

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Chapter 3 Legal Framework

Marine species

Under the United Nations Convention on the Law of the Sea, Australia has rights and responsibilities over 16 million square kilometres of ocean – more than twice the area of the Australian continent. Within this area live thousands of marine species, some of which are unique to Australia and all of which contribute to making Australia the most biodiverse rich country in our region.

The Australian Government uses the EPBC Act to protect and manage threatened, migratory and marine species in the marine environment. Marine species are listed under the EBPC Act and includes sea snakes, seals, crocodiles, Dugong (Dugong dugon), marine turtles and all birds that occur naturally in Commonwealth marine areas.

Once listed as a marine species under the EPBC Act, it becomes an offence to kill, injure, take, trade, keep or move of any listed marine species in or on a Commonwealth area.

The marine species list established under the EPBC Act is available at: http://www.environment.gov.au/marine/marine-species/marine-species-list.

Migratory species

The EPBC Act is the Australian Government’s key piece of environmental legislation. Under the EPBC Act, actions that have, or are likely to have, a significant impact on nationally protected matters require approval from the Australian Government Minister for the Environment. One of these matters protected by the Act is migratory species; specifically those migratory species listed under the Convention on the Conservation of Migratory Species of Wild Animals (also known as the CMS or the Bonn Convention; www.cms.int/) and bilateral migratory bird agreements with Japan (JAMBA), China (CAMBA) and the Republic of Korea (ROKAMBA).

Australia’s list of migratory species is established under Section 209 of the EPBC Act and is available at: http://www.environment.gov.au/biodiversity/migratory-species.

Section 211(A to E) of the EPBC Act prohibits the killing, injuring, taking, trading, keeping or moving of any migratory species in or on a Commonwealth area, although certain exemptions are allowed for in Section 212. For places outside of Commonwealth areas, the EPBC Act prevents actions (Section 140) or approvals under Strategic Assessments (Section 146L) that are inconsistent with Australia’s migratory species’ obligations under the CMS, JAMBA, CAMBA or ROKAMBA.

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Under the CMS, species are listed on Appendix I or Appendix II (or both), with Appendix I species recognised as endangered. Parties to the Convention that are Range States of a migratory species commit to prohibiting the taking of animals listed in Appendix I, and endeavour:

 to conserve and, where feasible and appropriate, restore those habitats of the species which are of importance in removing the species from danger of extinction;

 to prevent, remove, compensate for or minimize, as appropriate, the adverse effects of activities or obstacles that seriously impede or prevent the migration of the species; and

 to the extent feasible and appropriate, prevent, reduce or control factors that are endangering or are likely to further endanger the species, including strictly controlling the introduction of, or controlling or eliminating, already introduced exotic species.

Appendix II species are those that have an unfavourable conservation status and which require international agreements for their conservation and management, as well as those that would significantly benefit from the international cooperation that could be achieved by an international agreement.

Migratory species included in either Appendix can also benefit from the development of Concerted Actions. These range from field research and conservation projects to the establishment of technical and institutional frameworks for action. International Single Species Action Plans are an important instrument to promote and coordinate activities that seek to protect and restore habitat, mitigate obstacles to migration and other factors that might endanger species.

Signatories to JAMBA, CAMBA and ROKAMBA are committed to taking appropriate measures to preserve and enhance the environment of migratory birds, in particular, by seeking means to prevent damage to such birds and their environment.

These agreements also commit the governments to exchange research data and publications, to encourage formulation of joint research programs, and to encourage the conservation of migratory birds.

Actions that have or are likely to have, a significant impact on a listed migratory species (or other protected matter) must be referred to the Department for a decision on whether further assessment and approval is needed under the EPBC Act before an action can be undertaken.

An action is likely to have a significant impact on a migratory species if there is a real chance or possibility that it will:

 substantially modify (including by fragmenting, altering fire regimes, altering nutrient cycles or altering hydrological cycles), destroy or isolate an area of important habitat for migratory species;

 result in an invasive species that is harmful to the migratory species becoming established in an area of important habitat for the migratory species; or

 seriously disrupt the lifecycle (breeding, feeding, migration or resting behaviour) of an ecologically significant proportion of the population of a migratory species.

Further information of significant impact criteria can be found in the EPBC Act Policy Statement 1.1 Significant Impact Guidelines – Matters of National Environmental Significance.

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Agreement on the Conservation of Albatross and Petrels

The Agreement on the Conservation of Albatrosses and Petrels (ACAP) is a legally binding international treaty which entered into force on 1 February 2004. It was established in order to halt the alarming decline of seabird populations in the Southern Hemisphere, particularly albatrosses and petrels. Albatrosses and petrels are threatened by introduced species on their breeding islands, pollution, and being taken as bycatch in commercial and artisanal fisheries using a range of different gear. The agreement requires that measures be taken by signatory governments to reduce bycatch; protect breeding colonies; and control and remove introduced species from breeding sites, especially on islands.

Currently, ACAP protects all the world's albatross species, seven Southern Hemisphere petrel and two shearwater species. The agreement demonstrates an increasing international commitment to protect albatrosses and petrels.

ACAP helps countries to implement species action plans, control the expansion of non-native predators, introduce measures to reduce bycatch of seabirds, and support research in the effective conservation of albatrosses and petrels. The agreement has published ACAP Species Assessments, booklets, mitigation factsheets, and a number of ACAP Conservation Guidelines, including for biosecurity; eradication of introduced mammals; translocation; and census and survey methods. One of the agreement's main activities is to provide expert advice on seabird bycatch mitigation to fisheries managers, both in domestic and high seas fisheries. Further information about ACAP can be found here: https://www.acap.aq/.

While the CMS, ACAP, JAMBA, CAMBA and ROKAMBA provide mechanisms for pursuing conservation outcomes for migratory birds, they do not encompass all seabirds and are binding on a limited number of countries. As Australia became increasingly concerned about the conservation status of species, additional mechanisms have been developed for multilateral cooperation on biodiversity conservation globally and throughout the region.

Convention on the Conservation of Antarctic Marine Living Resources

The Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) is an international treaty that was adopted at the Conference on the Conservation of Antarctic Marine Living Resources which met at Canberra, Australia, 7–20 May 1980. The convention’s objective is the conservation of Antarctic marine living resources where conservation includes sustainable harvesting.

The treaty is a multilateral response to concerns that unregulated increases in krill catches in the Southern Ocean could be detrimental for Antarctic marine ecosystems particularly for seabirds, seals, whales and fish that depend on krill for food. It takes whole ecosystem and precautionary approaches to management.

Whilst this wildlife conservation plan does not include Australian Antarctic Territory restricted species, CCAMLR is still a relevant legal framework related to the

conservation of seabirds in the Southern Ocean.

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CCAMLR applies to all Antarctic populations of finfish, molluscs, crustacean and seabirds found south of the Antarctic Convergence, however, there are some species which do move beyond the Convergence to Australian waters which may rely on Antarctic resources, additionally there are some complementary CCAMLR measures around international actions to reduce the incidental mortality of seabirds arising from fishing. Further information on the Convention is available here: https://www.ccamlr.org/en.

Convention on Biological Diversity

The Convention on Biological Diversity (CBD) was inspired by the world community's growing commitment to sustainable development. It represents a step forward in the conservation of biological diversity, the sustainable use of its components, and the fair and equitable sharing of benefits arising from the use of genetic resources.

Australia is one of 196 Parties to CBD who are committed to implementing provisions of the Convention through National Biodiversity Strategies and Action Plans (NBSAP). NBSAPs are the principal instruments for implementing the Convention at the national level (Article 6). The Convention requires countries to prepare a national biodiversity strategy (or equivalent instrument) and to ensure that this strategy is mainstreamed into the planning and activities of all those sectors whose activities can have an impact (positive and negative) on biodiversity. Further information on Australia’s biodiversity strategy is available here: http://www.environment.gov.au/biodiversity/conservation/strategy.

Ramsar Convention on Wetlands

Australia is a signatory to the Convention on Wetlands of International Importance (see www.ramsar.org). The Ramsar Convention, as it is commonly known, is an intergovernmental treaty dedicated to the conservation and ‘wise use’ of wetlands.

The Ramsar Convention focuses on conservation of important habitats rather than species. Parties are committed to identifying wetlands that qualify as internationally significant against a set of criteria, nominating these wetlands to the List of Wetlands of International Importance (the Ramsar List) and ensuring the maintenance of the ecological character of each listed Ramsar site.

As at June 2020, Australia has 66 Wetlands of International Importance that cover a total of approximately 8.1 million hectares. Many of Australia’s Ramsar sites were nominated and listed using waterbird-based criteria, and in some of these cases seabirds are a major component of the waterbird numbers (e.g. Ramsar sites in the Coral Sea Marine Park, Ashmore Reef Marine Park and Pulu Keeling National Park). Some Ramsar sites that may not have been specifically listed for their waterbird-related values however contain critical components that are used by waterbirds. This includes use as migratory and localised feeding or roosting areas.

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East Asian—Australasian Flyway Partnership

The Partnership for the Conservation of Migratory Waterbirds and the Sustainable Use of their Habitats in the East Asian–Australasian Flyway (East Asian— Australasian Flyway Partnership (EAAFP)) was launched on 6 November 2006. A Ramsar regional initiative, the partnership is an informal and voluntary collaboration of effort focusing on protecting migratory waterbirds, their habitat and the livelihoods of people dependant on them.

The EAAF is one of nine major migratory waterbird flyways around the globe. It extends from within the Arctic Circle in Russia and Alaska, southwards through East and South-east Asia, to Australia and New Zealand in the south, encompassing 22 countries. Migratory waterbirds share this flyway with 45 per cent of the world’s human population. The EAAF is home to over 50 million migratory waterbirds—including shorebirds, Anatidae (ducks, geese and swans), seabirds and cranes—from 207 species, including 33 globally threatened and 13 near threatened species.

Flyway partners include countries, intergovernmental agencies, international non-government organisations and the international business sector. A cornerstone of the partnership is the establishment of a network of internationally important sites for migratory waterbirds throughout the EAAF. The partnership operates via working groups and task forces, including the Seabird Working Group. More information about the Partnership is available at: www.eaaflyway.net.

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Chapter 4 Species covered under the wildlife conservation plan

The Plan includes 73 species of seabird that occur or regularly visit Australia and its EEZ. The Plan does not include Australian Antarctic Territory restricted species, vagrant seabirds, ACAP-listed albatrosses and petrels or those species that are listed as threatened under the EPBC Act. Threatened species receive separate, approved conservation advice and, in some cases, a recovery plan which sets out what should be done to stop the decline and support the recovery of the species.

Based on expert opinion, three raptor species – White-bellied Sea-eagle (Haliaeetus leucogaster), Brahminy Kite (Haliastur indus) and Osprey (Pandion haliaetus) have also been included in this Plan as they all rely on the marine environment to complete their lifecycle and would all benefit from a national framework to coordinate research and management actions.

If, during the life of this Plan, a seabird species listed in Table 1 becomes a listed threatened species under the EPBC Act, the plan will cease to apply to that species. In the situation where a threatened seabird species is delisted, it will be eligible to be included in this plan as long as the species is also listed as migratory, and/or marine under the EPBC Act. If any seabird species that is currently considered a vagrant were to be recorded on a regular basis, monitoring programmes for the species should be supported to determine whether inclusion under the EPBC Act is appropriate.

Additional information on each of these species can be found on the Department’s SPRAT profiles, including information on the listing status of the species under relevant state or territory legislation (see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl).

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TABLE 1 Marine and Migratory Seabirds Listed under the EPBC Act. Threatened species are not eligible to be included in a wildlife conservation plan and therefore are not included (see page 52 for more information)

continued ...

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Table 1continued ...

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TABLE 1 Marine and Migratory Seabirds Listed under the EPBC Act. Threatened species are not eligible to be included in a wildlife conservation plan and therefore are not included (see page 52 for more information) continued

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Chapter 5 Threats

In Australia, threats to seabird populations can generally be attributed to one of four broad categories: biological, climate, resource use or chemical. Key threats to the survival of Australian seabirds are identified in this section. The list is not exhaustive but identifies the main threats that are likely to affect seabird populations adversely.

Habitat loss

Coastal development

Development pressures affect many species as human populations grow and we expand our coastal and urban footprint. Coastal development such as housing estates, roads, ports, windfarms and industrial areas can reduce or eliminate areas for seabirds to breed and forage. Tourism or industry developments on offshore islands can also lead to a reduction of the area available for nesting seabirds like terns and shearwaters. Secondary impacts of coastal and urban development can include increased disturbance, roaming domestic pets, light pollution and energy infrastructure (covered below).

The settlement of offshore islands, such as the Cocos (Keeling) Islands, has led to a decline in the distribution of breeding seabirds. Before human occupation of the islands in the 19th century, seabirds bred on all Cocos (Keeling) atolls. Now the only significant seabird breeding colonies are restricted to Pulu Keeling National Park. The site regularly supports more than 30,000 pairs of Red-footed Booby; 15,000 Common Noddy and 3,000 Great and Lesser Frigatebirds.

Loss of areas that support large numbers of seabirds can cause disproportionate declines in seabird populations, as displaced birds are unable to find suitable replacement habitat. Similarly, incremental loss of smaller areas affects the broader conservation of habitat availability. In Australia, loss of important habitat reduces availability of foraging and roosting areas, affecting the ability of birds to build up energy stores necessary for successful migration and breeding. Some areas are also important year-round for juvenile birds, with loss of these habitats affecting future breeding populations of these species.

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Habitat may be lost due to a variety of activities that make the habitat unavailable to seabirds. These may include direct loss through clearing, inundation, infilling or draining (for example, for buildings or marine services such as harbours, marinas, ports or oil terminals) or indirect loss through changes to hydrology, water quality or vegetation structural changes near breeding and roosting areas (for example increased vegetation cover or encroachment of buildings).

When assessing a development proposal, all direct and indirect impacts that have, will have, or are likely to occur on a protected matter as a result of the action must be considered.

Habitat modification

Seabirds are sensitive to subtle changes to their habitat. In particular, many have specialised feeding techniques making them susceptible to slight changes in prey availability or to their foraging environments. An activity that reduces the ability of seabirds to use an area for breeding, roosting or foraging, or reduces the availability of food, degrades habitat may have adverse impacts on the population. These impacts include (among others):

 alteration of nesting trees, ground substrate or burrows, sand spits used for roosting or inshore feeding areas such as seagrass beds, estuaries and coastal wetlands;

 substantial loss of marine or estuarine vegetation which is likely to alter the dynamic equilibrium of sediment banks and mudflats;

 invasion of coastal weeds;

 livestock (i.e. trampling burrows) and fire management at nesting areas, including on islands;

 water pollution and changes to the water regime, including the construction of dams and water management;

 artificial changes to hydrological regimes that affect the productivity of the feeding environment (for example, changes in water depth); and

 exposure of acid sulphate soils changing the chemical balance of the area.

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Climate variability and change
Climate change

Most extreme climatic events are beyond our immediate control, but it is important to monitor their effects on seabirds, particularly in the long term, in order to understand the background of natural influences against which to judge anthropogenic influences (Ross et al. 1996). The implications of extreme climatic events for Australian and Southern Hemisphere seabirds have been described by Chambers et al. (2011, 2013, 2014) and by Rodriguez et al. (2019) for petrels and shearwaters.

Climate change is a threat that impacts many marine organisms including seabirds. The 'Loss of climatic habitat caused by anthropogenic emissions of greenhouse gases' has been declared a Key Threatening Process under the EPBC Act. The threat is described as reductions in the bioclimatic range within which a species or ecological community exists due to emissions induced by human activities of greenhouse gases. The listing of this threat recognises that it is occurring at a continental scale. Components of the process include: temperature rise; changes in rainfall patterns; changes to the El Niño Southern Oscillation; and sea level rise. Consequences to seabirds could include negative impacts from an increase in extreme weather events, reduced or changed prey abundance and distribution, and decrease in nesting habitat.

Changes to marine ecosystems have been linked to strengthening warm currents and ocean warming (Ridgway 2007; Steinacher et al. 2010; Wu et al. 2012). In Australia, marine productivity has decreased as a result of the strengthening East Australian Current and warming waters (Ridgway 2007, Wu et al. 2012) which is likely to affect seabirds (e.g. foraging impacts and distribution changes (Carroll et al. 2016; Gorta et al. 2019)). For example, high seabird diversity in the Tasman Sea is subject to increasing rates of ocean warming and decreases in productivity which is likely to adversely impact species in that region (Mott and Clarke 2018).

Several seabird species have been identified as being at high risk from exposure to climate change and sensitive to climate change (Garnett and Franklin 2014). These species include: White-bellied Storm-petrel (Tasman Sea), Wedge-tailed Shearwater, Little Shearwater (Tasman Sea), Soft-plumaged Petrel, White-necked Petrel, Kermadec Petrel and Masked Booby (Tasman Sea). Many other seabirds listed by Garnett and Franklin (2014) are sensitive to climate change and their exposure to climate change varies. Understanding the impacts of climate change on these species, and the management response, will vary. The impact of climate change on Australian’s seabirds requires further research that will inform actions that inform adaptation and resilience.

Projected sea level rises are likely to adversely affect beach-nesting seabirds such as terns and noddies in the short term, followed by ground nesting seabirds like gulls, boobies and burrowing species such as penguins, shearwaters and petrels on low lying coastal areas, islands and cays.

A reduction in the emissions of greenhouse gases requires an internationally coordinated effort. Australia is a signatory to relevant international agreements, and has made a commitment to limit, and reduce, greenhouse gas emissions. In addition, the states and territories are pursuing additional opportunities to abate greenhouse gas emissions in a cost-effective and environmentally sensitive manner.

Wildlife Conservation Plan for Seabirds 21

El Niño Southern Oscillation

Long-term climatic cycles caused by El Niño Southern Oscillation (ENSO) events can have profound effects on seabird colonies and breeding success (Schreiber and Burger 2002; Surman and Nicholson 2009; Chambers et al. 2013). For example, northward irruption of Southern Ocean species and subsequent mortalities are a feature of strong ENSO events. Oceanographic parameters play an important role in determining the distribution of many pelagic seabird species. The position of the front of the East Australian Current, the Subantarctic Convergence and the Leeuwin Current are all major cyclical features affecting marine productivity and seabird distributions in Australia.

Generally, effects of ENSO events on seabirds are seen first in the central Pacific where they develop and are the most severe, but parallel oceanographic and atmospheric changes occur in the Atlantic and Indian Oceans (Schreiber and Burger 2002). For example, during ENSO events, when the flow of the Leeuwin Current flow is weaker and the Southern Oscillation Index is low, reproductive effort and output was severely reduced for Lesser Noddy (Anous tenuirostris) and Common Noddy (A. stolidus) breeding at the Houtman Abrolhos, Western Australia (Surman and Nicholson 2009). The conditions appeared to result in low prey availability, which delayed the commencement of seabird breeding by up to two months and caused breeding failures (Surman and Nicholson 2009).

La Niña events can also impact seabirds. Cannell et al. (2012) observed negative impacts on breeding success and fledging mass of Little Penguin (Eudyptula minor) in Western Australia.

Storms and cyclones

Small populations such as those of White-tailed Tropicbird (Phaethon lepturus), Kermadec Petrel (Pterodroma neglecta) and Little Tern (Sternula albifrons) are vulnerable to stochastic events such as storms and cyclones. Storms and cyclones have the potential to have serious effects on the arrival points, nesting substrate, vegetation and wildlife on remote seabird breeding islands, in addition to impacting seabirds directly at sea. Such natural factors can place additional pressures on seabird populations already adversely affected by anthropogenic influences. However, stochastic events such as storms and cyclones are beyond the control of management authorities and have not been addressed for the species in this Plan.

Geological processes
Volcanism

Active volcanoes generally occur close to the major tectonic plate boundaries. They are rare in Australia because there are no plate boundaries on this continent. However, there are two active volcanoes located 4,000 kilometres south west of Perth in the Australian Antarctic Territory on Heard Island and the nearby McDonald Islands.

Mawson Peak, on Heard Island has erupted several times in the last decade and remains active. The volcano on McDonald Island, after being dormant for 75,000 years, became active in 1992 and has erupted several times since, the most recent in 2005. It is estimated that volcanic activity displaced more than 1 million pairs of Macaroni Penguins (Eudyptes chrysolophus) on McDonald Island after the 1992 eruptions, though satellite images show unidentified penguins that may be recolonising the area (Crossin et al. 2013).

22 Wildlife Conservation Plan for Seabirds

The other active volcanoes nearest Australia are in Papua New Guinea, New Zealand, South Pacific, Indonesia and the Philippines. Gas-rich sticky magmas dominate the Asia Pacific, making composite volcanoes and calderas the most common varieties in the region. These types of volcanoes threaten lives, property, agricultural lands and livelihoods throughout south-east Asia and the Australian region. While volcanoes can impact seabird colonies from time-to-time by removing suitable nesting habitat, they can also create new habitat which is colonised over time as conditions change and improve.

Earthquake, tsunami and landslips

Earthquakes are the vibrations caused by rocks breaking under stress. The underground surface along which the rock breaks and moves is called a fault plane. Apart from causing shaking, earthquakes of magnitude 4.0 or greater can also trigger landslides, which can cause casualties. The larger the magnitude of the earthquake, the bigger the area over which landslides may occur. Undersea earthquakes can cause a tsunami, or a series of waves which can cross an ocean and cause extensive damage to coastal regions and nearshore seabird populations (Viera et al. 2006; Reynolds et al. 2015).

In areas underlain by water-saturated sediments, large earthquakes, usually magnitude 6.0 or greater, may cause liquefaction. The shaking causes the wet sediment to become quicksand and flow. Subsidence from this can cause buildings to topple, and the

sediment might erupt at the surface from craters and fountains.

Landslips caused by earthquakes or heavy rainfall, can impact habitat used by seabirds. For example, in 2016, a landslip caused by a 7.5 magnitude earthquake in New Zealand significantly impacted the breeding colony of the globally endangered Hutton’s Shearwater (Puffinus huttoni). Hutton’s Shearwaters are small seabirds endemic to New Zealand that breed only in the Seaward Kaikōura Ranges. They breed at two sites about 8 kilometres inland – Kowhai Stream and Shearwater Stream - at altitudes between 1200-1800 metres. They make burrows in loose soil amongst tussocks, where they spend nearly six months raising their chicks. After the earthquake struck, it was thought that up to 25 per cent of the population may have been crushed by the landslide. Surveys following the earthquake suggested that an estimated 20–30 per cent loss of breeding burrows had occurred but adults had returned to breed.

Invasive species

Invasive species are one of the primary threats to seabirds around the globe (Baker et al. 2002; Jones et al. 2008; Croxall et al. 2012). Mammals such as cats (Felis catus), rodents (Rattus spp.), European Red Fox, dogs (Canis familiaris) and pigs (Sus scrofa) predate adults, chicks and eggs and have caused localised extinctions. Goats (Capra hircus), cattle (Bos spp.) and rabbits (Oryctolagus cuniculus) alter breeding areas making them unsuitable for breeding or reducing breeding success. On Bird Island, Seychelles, the invasion of Yellow Crazy Ants (Anoplolepis gracilipes) led to an estimated 60,000 pairs of Sooty Tern (Onchoprion fuscatus), which nest in colonies on the ground, being displaced from their nesting sites and also caused the death of White Tern (Gygis alba) chicks (Feare 1999). Yellow Crazy Ants may also take over nesting sites of known tree-hollow nesting birds and the constant acid spraying behaviour of crazy ants causes injuries to seabird chicks. The Yellow Crazy Ant has been identified as a threat to breeding seabirds and other biological assets on Christmas Island. Control efforts are underway to reduce the impacts on wildlife including baiting and biological control.

The solution seems simple – eradication of invasive species – but the implementation of such programs is logistically difficult and expensive.

Wildlife Conservation Plan for Seabirds 23

One of Australia’s most successful programs to eradicate invasive species from an island was the Macquarie Island Pest Eradication Project. Since its discovery, a number of invasive invertebrates, mammal and bird species had been introduced to Macquarie Island. Some have had serious impacts on the island's native flora and fauna. Horses (Equus caballus), donkeys (E. asinus), pigs, cattle, goats, dogs and sheep (Ovis aries) were the first to be removed or die out naturally, and between 1989 and 2000, Weka (Gallirallus australis) and cats were eradicated. A major project to remove the last remaining mammal species - rabbits, Black Rats (Rattus rattus) and House Mice (Mus musculus) was undertaken between 2007 and 2014 thanks to a joint commitment of $24.7 million by the Australian and Tasmanian Governments to fund the eradication project. Aerial baiting of the entire island was completed in July 2011, followed by intensive monitoring by hunters and highly trained detection dogs, to detect and dispatch any surviving individuals. In April 2014, after nearly three years of monitoring with no sign of surviving individual rabbits, rats or mice, the project was declared a success. With the removal of rabbits and the resulting intensive grazing pressure, the island's vegetation is rapidly rebounding. Seabirds, which had suffered predation of eggs and chicks by rats, are also returning in numerous areas.

Another conservation success due to an island eradication program is the recovery of the threatened Gould’s Petrel (Pterodroma leucoptera) on NSW’s Cabbage Tree Island. In 1989 it was the sole Australian breeding site with just 250 breeding pairs. Adults were being killed by native Pied Currawongs (Strepera graculina) because rabbits had eaten out the understorey. Chicks were also becoming entangled in the sticky fruits of Pisonia trees (Pisonia umbellifera). Since eradication of rabbits, the removal of Pisonia trees, and establishment of additional breeding populations on other islands, numbers are continuing to grow.

Australian seabird islands facing invasive species issues include Ashmore Reef, Norfolk Island, Christmas Island and Cocos (Keeling) Island. These important seabird islands may benefit from pest eradication programs, provided the impacts of these invasive species and role with ecosystems is understood.

Control of pest plants on offshore islands can be challenging, particularly where freshwater is scarce, and carting of water (required for mixing herbicide) to islands is problematic. Integrated methods of spraying, burning and revegetating have proved effective on some New South Wales islands. Research and field trials into more effective control methods for weeds that impact seabird islands are a worthwhile priority, particularly species like Tree Mallow (Malva arborea) which require seasonal slashing.

Some weed species may provide important habitat, or be stabilising beaches, dunes or sand islands, and weed control around seabird colonies must be carefully planned. Species such as Little Penguin burrow under woody weeds, such as Boxthorn, and weed removal can alter burrow conditions like humidity or temperature. Removal of native vegetation and weeds may result in erosion that impacts available habitat, or in some cases, total loss of sand spits islands.

24 Wildlife Conservation Plan for Seabirds

Native wildlife

The influence of native species on the breeding success of seabirds should not be over-looked. Prior to the Macquarie Island Pest Eradication Project, it was believed that the population of Brown Skuas (Stercorarius antarcticus) on the island were being kept artificially high as a result of the availability of introduced rabbits as prey (Ross et al. 1996). Following the eradication of introduced rabbits, there was increased predation pressure by Brown Skua on native seabird colonies (i.e. prey switching from rabbits to seabirds).

Silver Gulls (Chroicocephalus novaehollandiae) can pose a threat to seabirds, particularly around tourist developments and human refuse (Smith 1991, 1992; Egan and Smith 1994). Kelp and Silver Gulls are known to raid tern colonies for eggs and young chicks and in large numbers have the ability to inflict a heavy toll on nesting seabirds (Serventy et al 1971; Ross et al. 1996). Increased abundance of gull species has been related to poor management of waste disposal (Coulson and Coulson 1983) and poor feed management at aquaculture facilities (Harrison 2010). Maintaining and improving good management practices at waste and aquaculture facilities may be important in reducing predation impacts to seabird colonies.

Long-nosed Fur Seals (Arctocephalus forsteri) are known to predate Little Penguins in South Australian and western Victoria. Numbers of fur seal are recovering from severe harvesting in the 1800s (Shaughnessy et al. 2015). The increasing trend in South Australia is likely to continue into the foreseeable future, primarily by expansion in colonies on Kangaroo Island and by establishment of new colonies (Shaughnessy et al. 2015). Long-nosed Fur Seals will eat Little Penguins whereas Australian Fur Seals (A. pusillus) do not (Hume et al. 2004, Page et al. 2005) and Australian Sea Lions do so very rarely (McIntosh et al. 2006). In studies of the occurrence of Little Penguin remains in scats and regurgitates of Long-nosed Fur Seal, the occurrence is around 30 per cent in South Australia and western Victoria (Bool et al. 2007, Page et al. 2005). Predation of Little Penguins by Long-nosed Fur Seals has been identified as a plausible cause of penguin decline in some colonies.

Fisheries interactions and by-catch

From time-to-time seabirds may interact with fishing boats that use certain fishing gears, particularly trawl, longline, purse seine and gillnet gear (Clay et al. 2019). Incidental mortality (bycatch) in fisheries remains one of the greatest threats to seabirds globally (Clay et al. 2019). Birds are attracted to fishing vessels as a source of food, particularly when bait, by-catch and fisheries waste and offal is being thrown back into the ocean.

An ‘interaction’ is any physical contact a person, boat or fishing gear has with a protected species that causes the animal stress, injury or death (AFMA 2019). Interactions with seabirds in trawl fisheries occur when birds foraging on discards or offal are injured or killed on collision with net monitoring and warp cables, dragged underwater and drowned when their wings become entangled around the warp, or become entangled in nets. Birds can also get caught on the hooks of longlines when the gear is being deployed or retrieved and the birds are chasing the bait.

Wildlife Conservation Plan for Seabirds 25

In Australia, the Australian Fisheries Management Authority (AFMA) collects data on interactions with protected seabirds through its monitoring programs. All fishers are required to report any interactions they have with seabirds through their logbooks. AFMA officers can also travel as observers on Australian fishing boats to collect biological data and make environmental observations which contributes to the monitoring of fishing interactions with protected species. Electronic monitoring of fishing activities, including interactions with seabirds, through the mounting of electronic monitoring systems on fishing vessels, is also being used in

Commonwealth fisheries.

AFMA and industry work in partnership to minimise and avoid interactions with protected seabirds. For example, fishery operations in Commonwealth longline fisheries are guided by the Australian Government’s Threat Abatement Plan for the incidental catch (or bycatch) of seabirds during oceanic longline fishing operations (2018). This threat abatement plan was developed to address the key threatening process of ‘the incidental catch (or bycatch) of seabirds during oceanic longline fishing operations’. The key threatening process was listed in July 2000 under the EPBC Act. This threat abatement plan is considered to be a feasible, effective and efficient approach to abating the threat to Australia’s biodiversity from the incidental catch (or bycatch) of seabirds during oceanic longline fishing operations. The threat abatement plan binds the Commonwealth and its agencies to respond to the impact of oceanic longline fishing on seabirds, and identifies the research, management and other actions needed to reduce the impacts of the key threatening process to an acceptable level.

The Australian Government has also developed a National Plan of Action for Minimising the Incidental Catch of Seabirds in Australian Capture Fisheries (NPOA–Seabirds). NPOA–Seabirds is a voluntary measure that has been developed to provide a comprehensive and nationally consistent approach to reducing the impact of fishing on seabirds. It draws together existing regulatory and voluntary management arrangements into one document and provides additional guidance for future management decisions around seabird mitigation measures.

The plan provides guidance on best practice mitigation, monitoring and reporting of seabird interactions. It aims to reduce duplication, target responses to areas identified as having the strongest need, and assist fisheries managers and industry towards more uniform, efficient and cost-effective seabird bycatch management.

AFMA also uses seabird management plans to reduce fishing interactions with protected seabirds. Seabird management plans are tailored to individual fishing boats and identify the main threats posed to seabirds by that boat. It also sets out the mitigation measures the concession holder has agreed to implement to reduce the risk of seabird interactions.

Mitigation measures are another way to reduce interactions between fisheries and seabirds. A range of measures is available that can minimise bycatch, and improvements and novel approaches are still being researched. Although some approaches are widely advocated, none is 100 per cent effective in isolation. There is extensive variation in operational and gear characteristics among fisheries, and they may overlap with different assemblages of seabirds which vary in susceptibility to capture. Consequently, mitigation needs to be tailored carefully, and if introduced in combination with close monitoring of compliance has been very effective (Phillips et al. 2016).

Further information on mitigation devices can be reviewed here: https://www.afma.gov.au/sustainability-environment/bycatch-discarding/ bycatch-reduction-devices.

26 Wildlife Conservation Plan for Seabirds

Prey depletion

Long-term demographic studies show that seabird populations may suffer from competition with fisheries (Bertrand et al 2012; Grémillet et al. 2018). Tuna fisheries are thought to have reduced prey availably for a number of procellariforms as many species rely on tuna to herd shoals of small fish to the surface where they become available for surface-feeding birds (Au et al. 1986; Furness 2003; Brooke 2004). Harvesting of marine resources can affect marine ecosystems and predator-prey interactions by the removal or redistribution of biomass central to pelagic food webs. In particular, fisheries targeting forage fish and euphausiids may be in competition with seabirds for food resources. Understanding this process is critical for the implementation of a whole of ecosystem approach to fisheries management.

Resource extraction

The effects of terrestrial mining can be profound and have direct consequences on seabirds and their habitats, or indirect impacts via disturbance or pollution. Guano mining in the 19th and 20th Centuries led to the human colonisation of many seabird breeding islands for so called ‘white gold’. Important island habitats were severely modified to fuel the demand for the highly effective fertilizer. Colonisation also spread invasive species which helped accelerate seabird declines on some islands. Even today, some historical guano mines have yet to recover from mining activities and will take hundreds of years to recover fully, if at all.

Whilst the impacts of tailings storage facilities mainly affect waterfowl and passerines, better knowledge of tailings dam ecology is required to develop site-specific monitoring and mitigation to better understand risks posed to wildlife, including seabirds (Smith et al. 2008). Solar-powered floating deterrent beacons with sonic guns have been trialled at ponds to deter species such as gulls and terns and some shorebirds (Read 1999). The Australian Government recommends monitoring of wildlife impacts and reducing the risks associated with the storage of water on tailings storage facilities, which could involve perimeter fencing, minimising the area of ponded water, netting or intermittent noise to distract birds (Commonwealth of Australia 2016).

The recently discovered breeding sites of Tahiti Petrel (Pseudobulweria rostrata) in New Caledonia are all in areas threatened by nickel mining (Spaggiari and Baré 2004, Delelis et al. 2007, Le Breton 2008), with mining activities predicted to have severe negative impacts on breeding success and potential adult mortality through ingestion of harmful materials. Threats such as these need to be minimised to avoid accelerating population declines.

Seabirds are known to aggregate around oil and gas platforms in above average numbers due to night lighting, flaring, food concentrations and other visual cues (Wiese et al. 2001). Bird mortality has been documented due to collision with the structure, oiling and incineration by the flares (Wiese et al. 2001). Implementing a comprehensive monitoring program of impacts of these offshore platforms should include nature, timing and extent of bird mortality caused by these structures. This information can then be used to better inform regulators responsible for exploration and extraction proposals.

Proposals for oil and mineral exploration and exploitation should be adequately assessed and, as appropriate, conditions imposed to ensure there are no adverse effects on seabirds or their habitats.

Wildlife Conservation Plan for Seabirds 27

Renewable energy

Marine renewable energy developments (MREDs) are becoming an increasing feature of the marine environment. MREDs are just one of several infrastructure developments in the marine environment that have the potential to impact seabirds. Globally, there is potential for generating energy from the marine environment in the form of extensive wind, wave and tidal-stream resources. However, the potential effects of MREDs on seabirds are not yet fully understood. Seabirds may be directly affected through collision with infrastructure or indirectly affected by displacement from foraging areas. A key question is how MREDs may affect seabird foraging success through changes in foraging behaviour and will be key to understanding whether large-scale installations could have impacts at a population level.

A key research area needed to address this issue is to better understand seabird distribution and foraging behaviour. This information will improve our understanding and be able to better predict adverse impacts in seabird populations.

Terrestrial windfarms in Tasmania have been reported to kill seabirds including diving-petrels, shearwaters, prions, storm-petrels and gannets from bird strikes (Hull et al. 2013). Species with large wingspans and relatively slow wingbeats are known to be susceptible to striking terrestrial windfarms, suggesting White-bellied Sea-Eagles, albatrosses and larger petrels may be at risk if offshore windfarms are constructed. Floating solar fields or deployment of solar fields over marine saltfield ponds and wastewater ponds may limit foraging opportunities for seabirds, conversely these may increase undesired roosting activity, fouling panels that may need mitigation.

Anthropogenic disturbance

Disturbance can be defined as any activity that changes the behaviour or physiology of one or more individuals within a colony (Gӧtmark 1999; Carney and Sydeman 1999; Nisbert 2000). Disturbance of seabirds causing adverse impacts can be classified in two broad categories: recreational disturbance and investigator disturbance (see reviews Gӧtmark 1999; Carney and Sydeman 1999; Nisbert 2000; Carey 2009). Recreational disturbance can be as simple as walking a dog on a beach close to nesting colonies of terns, causing them to flush off their nests. Investigator or researcher disturbance are activities affecting individual birds or nests such as marking nests, trapping, banding and handling of adults and their young.

Studies of breeding seabirds including gulls, shearwaters, penguins, boobies, gannets and cormorants have demonstrated that excessive disturbance can reduce reproductive success, reduce chick growth, disrupt feeding ecology and change physiological parameters (Gӧtmark 1999; Carney and Sydeman 1999; Nisbert 2000; Carey 2009). Efforts to reduce disturbance from recreational activities and researchers should be managed accordingly particularly when threatened species are involved or the breeding colony is small. For example, guidelines for visitors to seabird colonies in the Great Barrier Reef (GBRMPA 1997) and Macquarie Island (Tasmanian Parks and Wildlife Service 2018) have been developed to support tourist operations and researchers undertaking necessary biological investigations. GBRMPA have also developed guidelines for managing research in the Great Barrier Reef Marine Park (GBRMPA 2019).

28 Wildlife Conservation Plan for Seabirds

Hunting

Historically, a number of seabird colonies were exploited for their eggs, chicks and adults. In northern Australia fleets of Malayan trepang fisherman took large numbers of boobies and frigatebirds as fresh meat (Serventy et al. 1971) in places such as Ashmore Reef, but this has since largely ceased with the establishment of a marine park at Ashmore Reef in 1983. Historically, Cocos (Keeling) Islanders took large numbers of seabirds at North Keeling, particularly Red-footed Booby (Sula sula) prior to establishment of Pulu Keeling National Park in 1995. Protection of migratory species under the EPBC Act has made it an offence to kill many of the birds that the Cocos-Malay community had traditionally harvested with illegal poaching of seabirds both in the park and around the southern atoll an ongoing problem. In 1998 the Australian Federal Police implemented a gun control program under the National Firearms Program Implementation Act 1998 for registered firearms in the territory. This has helped to reduce the level of poaching of protected seabirds.

In Tasmania, Little Penguin, Black-faced Cormorant (Phalacrocorax fuscescens) and Short-tailed Shearwaters (Ardenna tenuirostris) have previously been used illegally by crayfishers as bait for their pots (Serventy et al. 1971). Historic impacts also extended to Australasian Gannets (Morus serrator) breeding on Cat Island with the species eventually expatriated in the 1980s (Serventy et al. 1971). Cat Island had been the largest gannet colony in Australia before its demise. The practice of egg collection or “egging” still occurs in some parts of northern Australia by Indigenous communities and Norfolk Island but is not considered a widespread threat to any seabird population.

The Native Title Act 1993 identifies activities such as hunting and fishing as potential native title rights and interests and permits Native Title holders to hunt certain species for the purposes of satisfying their personal, domestic or non-commercial communal needs. In Tasmania, there is an annual take of Short-tailed Shearwater chicks which is regulated by the Tasmanian Government. There are three separately managed harvests namely:

 Indigenous commercial harvest – undertaken on three islands; Trefoil Island off Tasmania’s north west coast in western Bass Strait; Great Dog (or Big Dog) Island and Babel Island, both in the Furneaux Island Group in Eastern Bass Strait. This harvest is licensed by the Tasmanian Government, but it does not undertake any monitoring on these sites or require harvesters to report numbers harvested. This industry is entirely self-managed with the community undertaking monitoring – no quotas are set by the Tasmaninan Government. However, the industry has been shown to self-manage, for example the community shut down harvest in 2014 due to low chick numbers. Season duration is restricted by the Tasmanian Government.

 Indigenous cultural harvest – undertaken under permit on a couple of small sites including (in recent years) South Arm and Cape Queen Elizabeth on Bruny Island, both in southern Tasmania and at Seymour on Tasmania’s east coast. The Tasmanian Government monitors the South Arm colony, the number of harvesters is restricted, and daily bag limits apply. There is also a small unreported cultural harvest on indigenous-owned islands.

 Recreational harvest – undertaken under license between 38 and 44 of Tasmania’s known 209 colonies (Skira et.al. 1996) and open to anyone eligible for purchasing a recreational license. Harvest areas include King Island and the Hunter Island Group both in western Bass Strait; the Furneaux Island Group in eastern Bass Strait and Tasmania’s West Coast, near Strahan. The season generally runs for 16 days with a daily bag limit of 25 birds (15 on the west coast).

Sooty Shearwaters (Ardenna grisea) and Grey-faced Petrels (Pterodroma gouldi) in New Zealand are subject to an annual harvest for their oil, feathers and meat (Rodriguez et al. 2019).

Wildlife Conservation Plan for Seabirds 29

Transport
Shipping

Ships may directly affect seabirds through their activities close to colonies or roost sites. For example, the bright deck lights of some ships may disturb and disorientate roosting seabirds as well as cause collision with birds (discussed further in Light Pollution below). Indirect influences relate to pollution from ships such as oil spills and garbage.

The use of boats or other watercraft close to breeding islands and roost site requires regular monitoring and assessment. Boat strike causing mortality of Little Penguins has been recorded in inshore coastal environments (Cannell et al. 2016).

Aircraft

The passage of aircraft, particularly those flying low over breeding islands, may adversely affect colonies through excessive disturbance. This has been documented in Australia, mainly in the Great Barrier Reef. Hicks et al. (1987) found that Sooty Terns and Common Noddies breeding on Michaelmas Cay took flight in reaction to the landing and departure of seaplanes within 400 m. On Lady Elliot Island in the southern Great Barrier Reef, small commercial aircraft regularly land on an airstrip which bisects the island. The airstrip is several meters from breeding colonies of Crested (Thalasseus bergii) and Bridled Terns (O. anaethetus) and Common Noddies. Apart from the occasional bird strike, no studies have been made on the potential impact on breeding success or displacement. Helicopters are used in the Great Barrier Reef to transport tourists to some resort islands. Frequency, approach and overflight height are all potential issues that impact nesting seabirds. Some species may be more sensitive to aircraft, whereas at sites regularly exposed to aircraft, the disturbance may be less severe due to habituation (Giese 1998; Giese and Riddle 1999).

In some areas, local no-fly guidelines have been implemented around nesting areas for White-bellied Sea Eagles to reduce the potential impacts of aircraft on individuals.

Drones

Drones are being increasingly used in innovative ways to enhance environmental research and conservation (Hodgson et al. 2018). Despite their widespread use for wildlife studies, there are few scientifically justified guidelines that provide minimum distances at which wildlife can be approached to minimize visual and auditory disturbance. Determining these distances is essential to ensuring that behavioural and survey data have no observer bias, and once understood, should form the basis of requirements for animal ethics and scientific permit approvals.

Drone disturbance may be species-specific, and it is possible that different avian taxa exhibit different behavioural disturbance thresholds. For example, Bevan et al. (2018) observed a colony of Crested Terns resting on a sand-bank displayed disturbance behaviours (e.g. flight response) when a drone was flown below 60 m altitude. At Raine Island National Park (RINP), Queensland, preliminary data suggests that other avian species are even more sensitive to drone disturbance than Crested Terns (Queensland Parks and Wildlife Service 2017). Official guidance for drone use within RINP indicates that drone altitudes of 80 and 120 m, respectively, are required to avoid disturbing Brown Booby (Sula leucogaster) and Common Noddy. These requirements suggest that drone disturbance may be species-specific, and that different avian taxa exhibit different behavioural disturbance threshold altitudes. Such thresholds for target species should be determined prior to initiating drone-based biological studies and monitoring.

30 Wildlife Conservation Plan for Seabirds

Pollution

Marine debris

Marine debris can affect seabirds either through ingestion or entanglement. Most of the marine debris affecting seabirds is derived from consumer waste. Many species ingest considerable quantities of plastic and other marine debris, which has a wide range of lethal or sub-lethal effects. The debris can cause physical damage, or perforation, mechanical blockage or impairment of the digestive system, resulting in starvation. Chicks appear to be at greater risk than adults because of their high rates of ingestion and low frequency of regurgitated casting of indigestible material. When the plastics are regurgitated to chicks, the physical impaction and internal ulceration are likely to lower survival. In addition, the chick receives less food, lowering its nutrient intake and increasing its chances of starvation (Fry et al. 1987; Sileo et al. 1990). For example, as part of the ongoing marine debris surveys in Gulf St Vincent, South Australia, opportunistic necropsy was undertaken on 23 carcasses of Short-tailed Shearwaters that had died and washed up on Goolwa and Waitpinga beaches. These deaths were part of a large-scale mortality of hundreds of these birds across southern Australia, probably due to poor body condition after their seasonal migration from the northern hemisphere. In the study, 70 per cent of the birds had plastic fragments in their gut, which can be passed on to their young by the regurgitation of food (see Carey 2011).

Some seabirds are also killed after becoming entangled in marine debris (Nel and Nel 1999). Such entanglement can constrict growth and circulation, leading to asphyxiation. Entanglement may also increase the bird's drag coefficient through the water, causing the animal to die due to reduced ability to catch prey or avoid predators. The rate of this source of mortality remains completely unknown for Australian species.

Injury and Fatality Caused by the Ingestion and Entanglement of Marine Life in Marine Debris has been listed a Key Threatening Process under the EPBC Act. It was considered that 20 listed threatened species are adversely affected by marine debris.

The problems of plastic ingestion and entanglement may affect many Australian breeding petrels and has been reviewed in Baker et al. (2002) and Rodriguez et al. (2019). While it is likely that many seabirds ingest plastic debris without it being observed or documented, and birds may become entangled in marine debris from time to time, there is currently no evidence to suggest that ingestion or entanglement are posing a significant threat to any Australian seabird species at the population level.

Light pollution

In response to concerns about light pollution, the Australian Government developed National Light Pollution Guidelines for Wildlife Including Marine Turtles, Seabirds and Migratory Shorebirds (Commonwealth of Australia 2020) aimed to raise awareness of the potential impacts of artificial light on wildlife and provide a framework for assessing and managing these impacts around susceptible listed wildlife.

Artificial light associated with the urbanisation of coastal areas has been linked to increased seabird mortality (Gineste et al. 2016) and today, 56 petrel species worldwide are known to be impacted by artificial lighting (Rodriguez et al. 2017a,b,c).

All species of seabird are vulnerable to impacts from lighting. Problematic sources of artificial light include coastal residential and hotel developments, street lighting, vehicle lights, sporting facility floodlights, vessel searchlights, cruise ships, fishing vessels, research vessels, gas flares, security lighting, navigation aids and lighthouses (Montevecchi 2006, Rodriguez et al. 2012, 2017a, Raine et al. 2007, Ainley et al. 2001, Troy et al. 2011, Merkel & Johannsen 2011, Black 2005, Deppe et al. 2017).

Wildlife Conservation Plan for Seabirds 31

High rates of “fallout”, or the collision of birds with structures, has been reported in seabirds nesting adjacent to urban or developed areas (Montevecchi 2006, Rodriguez et al. 2017a, Podolsky et al. 1998). Light sourced impacts have also been reported from offshore oil platforms, including gas flares (Bourne 1979, Wiese et al. 2001, Burke et al. 2005).

Adult seabirds are less impacted by artificial lighting than fledglings.

Many procellariforms species (i.e. shearwaters, storm petrels, gadfly petrels) are vulnerable to artificial lighting during nocturnal activities which make up part of the annual breeding cycle. Adult procellariforms are vulnerable when returning to and leaving the nesting colony. They may leave or enter to re-establish their pair bonds with breeding partners, repair nesting burrows, defend nesting sites or to forage. A recent study showed artificial light disrupts adult nest attendance and thus affects weight gain in chicks (Cianchetti-Benedetti et al 2018).

Fledglings are more vulnerable to artificial light than adults due to the naivety of their first flight, the immature development of ganglions in the eye at fledging and the potential connection between light and food (see Montevecchi 2006 and Mitkus et al 2018). Emergence during darkness, believed to be a predator-avoidance strategy (Watanuki 1986) may increase vulnerability to impacts from artificial lighting (Reed et al. 1985). Artificial lights are thought to override the sea-finding cues provided by the moon and star light at the horizon (Telfer et al. 1987) and fledglings can be attracted back to onshore lights after reaching the sea (Rodriguez et al 2014, Podolsky et al 1998). It is possible that fledglings that survive their offshore migration cannot imprint upon their natal colony, preventing them from returning to nest when they mature (Raine et al. 2007). The consequences of exposure to artificial light on the viability of a breeding population of seabirds is unknown (Greisheimer and Holmes 2011).

Chronic pollution

Chemical contamination has been clearly implicated in the decline of a number of seabirds. Its relevance to the conservation of albatrosses and petrels has been reviewed by Baker et al. (2002) and includes deleterious effects through diminished reproductive success caused by eggshell thinning, embryo viability and offspring deformities. Elevated levels of chemicals and heavy metals can be found in the plasma of adults, chicks and eggs of seabirds from every continent and virtually all islands across the globe. Organochlorines and heavy metals degrade very slowly in the environment, are retained by organisms and passed along the food chain, becoming increasingly concentrated. Tributyltin (TBT), whilst its use as an antifoulant has been widely reduced, can accumulate in sediments which can then be released upon disturbance. Consequently, top order predators, such as seabirds and coastal raptors, may accumulate high levels of chemicals in tissues, a problem which is exacerbated because these birds are long-lived and highly mobile species (Falkenberg et al. 1994).

Copley (1996) reported that nutrient enrichment or coastal eutrophication was the marine pollution issue with highest priority in South Australia, particularly with regards to inshore habitat loss of seagrass off the Adelaide metropolitan area and related impacts upon fish and coastal erosion. Flow-on effects of these impacts to seabird populations are not usually obvious but are nonetheless likely to occur (Copley 1996).

32 Wildlife Conservation Plan for Seabirds

Turbidity is implicated in coastal and deepwater seagrass habitat loss (Westphalen et al. 2006; Tanner 2006). The implications of turbidity related impacts from other activities such as dredging on seabirds is unclear. Turbidity may impact upon seabird feeding, for species which may need clear water to view prey (i.e. terns). For example, increased turbidity from European Carp in Murray Mouth lakes appeared to interfere with Australian Fairy Tern feeding (Copley 1996).

Pesticides accumulate in seabirds and species which had been tested in South Australia have had elevated organochlorine levels (Silver Gulls, Little Penguins, Australian Pelican, White-bellied Sea-eagle) (Falkenberg et al. 1994). There have been concerns over organochlorine pesticide contamination and reproductive failure in Osprey (Pandion haliaetus) and White-bellied Sea Eagle (Falkenberg et al. 1994). Pesticide levels were also of concern for several prey species commonly found in the diet of White-bellied Sea Eagle, such as Feral Pigeon and Silver Gull. DDT was also found at high concentration in pelican eggs. Concentrations found were well above those known to cause

reproductive failure in falcons (Falco spp.). Dieldrin was present in most samples, but at low concentrations (Falkenberg et al. 1994).

Agricultural land runoff containing pesticides may inhibit zooplankton grazing which can then result in algal blooms (Hallegraeff 1995). Harmful algal blooms can affect seabirds that feed on filter-feeding fish and shellfish. Harmful algal blooms can affect a range of marine species including seabirds, including reduced feeding activity, inability to lay eggs, loss of motor coordination and death, and impacts to seabird population recruitment (Shumway et al 2003). Systematic monitoring of blooms and impacts on marine species is needed to determine long-term impacts.

Hormones and endocrine disruptors which may be present in pesticides, agricultural runoff, antifouling and municipal and industrial effluent are known to impact on some fish species and other wildlife (Environment Canada 1999, ORD & USEPA 1998, Colborn et al. 1993). More recently concerns have been raised over Endocrine Disrupting Chemicals (EDCs) contained in Pharmaceuticals and Personal Care Products (PPCPs) which may enter aquatic environments in sewerage or reclaimed water (Ying et al. 2004). At certain concentrations chemicals such as estradiol, nonylphenol, bisphenol A, polychlorinated biphenyls (PCBs) and some pesticides can cause disruption to endocrine systems and can affect hormonal control of development in aquatic wildlife. Whilst poorly documented in Australia, one impact is the feminisation of fish by wastewater effluent from sewage treatment (Ying et al. 2004).

Marine pollution is becoming increasingly apparent in the Southern Hemisphere and impacts on Australian seabirds are likely to increase in the future. Internationally, only a few studies of any seabird species have been undertaken to identify whether marine contaminants (e.g. organochlorines and dichloro-diphenyl-trichloroethane (DDT) affect seabird survival, in particular aspects of their breeding biology (Croxall 1998; Ludwig et al. 1998).

Wildlife Conservation Plan for Seabirds 33

Acute pollution

Bulk fuel and oil spills also have the potential to affect high numbers of seabirds. Birds coming into contact with oil can become physically smothered, or suffer

oiled plumage, which leads to reduced insulation and increased heat loss, loss of waterproofing, reduced ability to forage efficiently, usually resulting in emaciation and death. Birds may also ingest oil, leading to potential toxicity. Since seabirds spend much of their time on the sea surface, they are particularly vulnerable to the hazards of oil or fuel spills and are difficult to rehabilitate. Shipping discharge of oil and other pollutants is regulated by the International Convention for the Prevention of Pollution from Ships (1973) and its Protocol (1978) - MARPOL 73/78. The Australian Maritime Safety Authority (AMSA) administers MARPOL in Australian waters under the Commonwealth Protection of the Sea (Prevention of Pollution from Ships) Act 1983.

Response to marine oil spills is managed by AMSA, in conjunction with the states and the Northern Territory, through the Intergovernmental Agreement on the National Plan to Combat Pollution of the Sea by Oil and Other Noxious and Hazardous Substances. The Plan sets out the role and responsibilities for government and industry in the event of an oil spill. The Plan identifies the potential effects on wildlife and the operations and procedures that should be put into place in the event of an oil spill. However, if the incident occurs in remote areas, there may be little that can be done when large numbers of birds are affected.

For offshore petroleum activities in Commonwealth waters, the titleholder is responsible for managing oil spill response (being accountable under the OPGGS Act and Environment Regulations). For oil pollution response in State and Territory waters, whether the incident occurs in the State/Territory waters or oil pollution migrates into State/Territory waters, the State/Territory authorities manage the response and provide direction to the responsible party (titleholder) to respond, which includes response to oiled wildlife.

In Port Bonython, South Australia an oil spill occurred on 30 August 1992 from the fuel tanker Era during berthing operations in upper Spencer Gulf. An estimated 300 000 litres (296 tonnes) of heavy bunker oil was released in sensitive mangrove and seagrass communities of upper Spencer Gulf. An estimated 23 hectares of mangroves subsequently died or totally defoliated in heavily oiled areas. There was a significant loss of birdlife. About 500 birds were affected, of which 300 required treatment. Species affected were mostly: cormorants, pelicans, terns, grebes, herons and ducks.

Two other ship-based events in Australasia (MV Iron Baron, Tasmania in 1995 (Giese et al. 2000, Goldsworthy et al. 2000a, b), and MV Rena in New Zealand in 2011 (Sievwright 2014, Chilvers et al. 2015) impacted numerous seabirds. When the Montara well spill (August 2009) in the Timor Sea released crude oil and gas condensate, 16 individual seabirds (noddies, shearwater, frigatebird and booby) were collected (Watson et al. 2009; Gagnon and Rawson 2010).

Heavy metals

The bio-accumulation of heavy metals in seabirds in the Australian region is complex as natural levels of some metals may be relatively high particularly in some fish species (Denton and Breck 1981; Lyle 1984). A study of levels of lead, mercury and cadmium in tropical terns in Australia (Burger and Gochfeld 1991) showed that levels of lead and mercury were highest in Black Noddy and cadmium levels were highest for Common Noddy and Sooty Tern and lowest for Black Noddy. The data indicates that levels of these heavy metals in tropical terns in Australia are similar to, or higher than, those reported from birds in temperate areas subject to industrial pollution.

34 Wildlife Conservation Plan for Seabirds

Heavy metal pollution has been an issue in the Adelaide metropolitan area and outside the upper Spencer Gulf (EPA 2004). Heavy metal contamination is known in marine mammals in South Australia’s gulfs, particularly cadmium which is assumed to be related to emissions from the Port Pirie smelter (Kemper et al. 1994). However, there is limited research on effects on seabirds in South Australia.

Wildlife exposure to metal contaminants may correlate with local anthropogenic emissions. Mott et al. (2017) investigated the feather mercury concentrations of adult and juvenile Lesser Frigatebirds (Fregata ariel) and Great Frigatebirds (F. minor) breeding in the eastern Indian Ocean. Low mercury concentration in juveniles relative to adults, higher mercury concentration in adult females than adult males, and a trend for Lesser Frigatebirds to have higher mercury concentration than Great Frigatebirds implicated non-breeding ground exposure as the major influence on mercury burden. The authors noted that aspects of the frigatebird foraging ecology were consistent with high exposure occurring in inshore waters of the non-breeding range, particularly in the South China Sea.

Seabirds (Fairy Prions, Pachyptila turtur) off Tasmania are known to have significantly higher cadmium levels in areas close to the source of cadmium pollution (Kemper, et al. 1994). Lavers and Bond (2013) detailed contaminant loads in Short-tailed Shearwaters, and recent studies in Tasmania and Western Australia in Little Penguins (Einoder et al. 2018; Dunlop et al unpublished data) showed high metal levels in penguin feathers from historical industrial discharges in estuarine environments.

In Western Australia, a study on Caspian Terns showed that most breeding adults had elevated levels of mercury in their tail feathers (mean 2.27 mg/kg) (Dunlop and McNeill 2017). Two of the sampled Caspian Terns had feather mercury levels above the threshold considered capable of producing deleterious effects (5 mg/kg, Burger & Gochfeld 2004); four individuals registered above 4 mg/kg (Dunlop and McNeill 2017). One bird with a feather mercury of 5.8 mg/kg was observed dying on the Peel Inlet three months after sampling, with symptoms consistent with nervous disintegration caused by mercury intoxication (Burger & Gochfeld 2004; Dunlop and McNeill 2017). These observations indicate that the Caspian Terns foraging in the southern metropolitan coastal waters of Perth may well be subject to an elevated level of mercury exposure (Dunlop and McNeill 2017). High mercury exposure would appear to be related to the increased eutrophication in these aquatic ecosystems.

The release of mercury from permafrost regions in the Arctic are likely to impact Arctic breeding seabirds that migrate to Australia. The extent to which the bio-accumulation of heavy metals reflects anthropogenic or geological sources and the role of the food chain requires further investigation in other species that breed in and migrate to Australia.

Aquaculture

The use of coastal land and nearshore waters for various types of aquaculture may have adverse consequences for a number of species. Few major problems have yet been experienced in Australia, but in South-East Asia, where aquaculture is a major industry, species such as cormorants become regarded as pest and integrated land-use planning is essential (White 1984).

In Australia, the largest aquaculture industries are present in Tasmania and South Australia. The tuna aquaculture venture using cages off Port Lincoln in South Australia has been attributed to increases in the number of Silver Gulls through the provision of food (Ross et al. 1996). Bacteriological discharges from aquaculture facilities may cause adverse problems if concentrations of pathogens are too high. Deaths of seabirds from sewage discharge have been documented in North America (Ankerberg 1984).

Wildlife Conservation Plan for Seabirds 35

The spread of the herpes virus in wild stocks of pilchards, causing mortality impacted

Little Penguins in southern Australia (Murray et al. 2003; Chiaradia et al. 2010).

The herpes virus is thought to have originated in feed used in aquaculture

(Gaughan et al. 2000).

Low levels of entanglement of seabirds and bird strikes (primarily gulls and cormorants)

occasionally resulting in low numbers of mortalities are known from Tasmania.

Current and proposed moves to offshore locations off southeast Tasmania may see

an increased level of interaction with Southern Ocean species such as albatrosses

and petrels.

The Australian Government has developed industry guidance for offshore aquaculture (DEH 2006), which provides specific guidance to the marine-based aquaculture industry to assist proponents to decide whether or not actions which they propose to take require assessment and approval under the EPBC Act.

Disease

Throughout their lifecycle, seabirds can contract a range of diseases such as

Newcastle disease (caused by avian paramyxovirus), avian influenza, avian cholera, and avian pox (Morgan et al. 1981; Weimerskirch 2004; Grimaldi et al. 2011;

Uhart et al. 2018). Infectious diseases have the potential to cause rapid decreases in seabird populations and pose a potentially major conservation problem for small or already declining populations.

Because seabirds spend large amounts of time at sea, the impact of diseases on seabirds is perhaps more difficult to detect than in terrestrial environments. Fortunately, in Australia no major disease outbreak causing mass mortality has been reported. Elsewhere, the global spread of avian cholera has been partly held responsible for the decline of Indian Yellow-nosed Albatross (Thalassarche carteri) and could be threatening other seabirds on Amsterdam Island in the Southern Ocean (Weimerskirch 2004).

Malaria-like blood parasites have been detected in some Little Penguin populations in Western Australia (Cannell 2013) and South Australia (Colombelli-Négrel, 2016), and noted worldwide in penguin populations (Grilo et al 2016). In Little Penguin colonies monitored across the Gulf St Vincent, South Australia, blood parasites (Haemoproteus and Plasmodium spp.) were identified in 86 per cent of the individuals sampled and individuals with multiple infections had longer bills than those with single infection or non-infected individuals. A South Australian penguin monitoring program recorded Little Penguin mortality from multiple organ failure directly related to blood parasites (Tomo and Kemper 2016). There is a need to identify parasite infections, viruses and vectors across colonies to better assess their impact on population trends.

In Australia, the National Avian Influenza Wild Bird (NAIWB) Steering Group was established in January 2006 to facilitate collaboration between State and Territory programs and non-government organisations undertaking surveillance for avian influenza. Primary Industry agencies agreed to strengthen national surveillance for avian influenza in both poultry and wild birds.

Activities under the NAIWB Surveillance Program are conducted Australia- wide. The Program has two main components: Targeted surveillance: pathogen-specific, risk-based surveillance via convenience sampling of apparently healthy, live and hunter-killed wild birds; and General (passive) surveillance: investigation of significant, unexplained morbidity / mortality events in wild birds, including captive and wild birds within zoo grounds. During 2017, targeted surveillance activities included testing of samples for avian paramyxoviruses (APMVs), predominantly targeting APMV-1.

36 Wildlife Conservation Plan for Seabirds

Results from the NAIWB Surveillance Program are used to inform policy development and planning by Australian government and state/territory government agencies and contribute to Australia’s National Animal Health Information System (NAHIS). The data also informs Australia’s international reporting; and summary data are provided to industry at regular intervals through each sampling year.

Threat prioritisation

Each of the threats outlined above has been assessed to determine the risk posed to seabird populations (Table 3) using a risk matrix (Table 2). This identifies the threats that are likely to have greater impacts on seabird populations and therefore actions to mitigate these threats can be prioritised accordingly. The risk matrix considers the likelihood of an incident occurring and the consequences of that incident. Threats may act differently on different species and populations at different times of year, but the precautionary principle dictates that the threat category is determined by the group at highest risk. Population-wide threats are generally considered to present a higher risk.

The risk matrix uses a qualitative assessment drawing on peer reviewed literature and expert opinion. In some cases, the consequences of the threat are unknown. In these cases, the precautionary principle has been applied. Levels of risk and the associated priority for action are defined as follows:

 Very High – immediate mitigation action required

 High – mitigation action and an adaptive management plan required, the precautionary principle should be applied

 Moderate – obtain additional information and develop mitigation action if required

 Low – monitor the threat occurrence and reassess threat level if likelihood or consequences change

Table 2 Risk prioritisation

Wildlife Conservation Plan for Seabirds 37

Categories for likelihood are defined as follows:

 Almost certain – expected to occur every year

 Likely – expected to occur at least once every five years

 Possible – might occur at some time

 Unlikely – such events are known to have occurred on a worldwide basis but only a few times

 Rare or Unknown – may occur only in exceptional circumstances; OR it is currently unknown how often the incident will occur

Categories for consequences are defined as follows:

 Not significant – no long-term effect on individuals or populations

 Minor – individuals are adversely affected but no effect at population level

 Moderate – population recovery stalls or reduces

 Major – population decreases

 Catastrophic – population extinction

TABLE 3 Seabird population residual risk matrix

38 Wildlife Conservation Plan for Seabirds

Chapter 6 Objectives

1 International cooperation and collaboration continue to support the survival of seabirds and their habitats outside Australian jurisdiction.

2 Seabirds and their habitats are identified, protected and managed in Australia.

3 The long-term survival of seabirds and their habitats is achieved through supporting

priority research programs, coordinated monitoring, on-ground management

and conservation.

4 Increase the awareness of the importance of conserving seabirds and their

habitats through community education and capacity building to support monitoring

and on-ground management.

Photograph of adult and young Red-tailed Tropicbirds on their next on Lady Elliot Island, the Great Barrier Reef

Wildlife Conservation Plan for Seabirds 39

Chapter 7 Actions to achieve specific objectives

Actions identified for the protection, conservation and management of the species covered by this plan are described below. Some of the objectives are long-term (>10 years) and may not be fully achieved during the lifetime of this wildlife conservation plan but actions identified will make incremental steps towards the successful progress towards of achieving desired objectives.

TABLE OBJECTIVE 1 International cooperation and collaboration continue to support the survival of seabirds and their habitats outside Australian jurisdiction

40 Wildlife Conservation Plan for Seabirds

TABLE OBJECTIVE 1 International cooperation and collaboration continue to support the survival of seabirds and their habitats outside Australian jurisdiction continued

Wildlife Conservation Plan for Seabirds 41

View image in the official sourceView image in the official source

TABLE OBJECTIVE 2 Seabirds and their habitats are identified, protected and managed in Australia

TABLE OBJECTIVE 2 Seabirds and their habitats are identified, protected and managed in Australia continued

Wildlife Conservation Plan for Seabirds 43

TABLE OBJECTIVE 2 Seabirds and their habitats are identified, protected and managed in Australia continued

44 Wildlife Conservation Plan for Seabirds

TABLE OBJECTIVE 3 The long-term survival of seabirds and their habitats is achieved through supporting priority research programs, coordinated monitoring, on-ground management and conservation

Wildlife Conservation Plan for Seabirds 45

TABLE OBJECTIVE 3 The long-term survival of seabirds and their habitats is achieved through supporting priority research programs, coordinated monitoring, on-ground management and conservation continued

46 Wildlife Conservation Plan for Seabirds

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Wildlife Conservation Plan for Seabirds 47

Chapter 8 Affected interests

Organisations likely to be affected by the actions proposed in this plan include: international multilateral and bilateral agreements; government agencies (Commonwealth, state and territory, local), particularly those involved with coastal and island environments and conservation programs; Indigenous land and sea management groups (including ranger programmes); researchers; bird watching groups; conservation groups; wildlife interest groups; 4WD and fishing groups; environmental consulting companies; tourism operators; industry and commercial bodies; and, proponents of coastal and island development in the vicinity of important habitat. This list however should not be considered exhaustive, as there may be other interest groups that would like to be included in the future or need to be considered when specialised tasks are required.

The following table lists some of the interest groups, how they could contribute to the success of the plan and the potential benefits/impacts that may emerge from the Plan’s implementation:

48 Wildlife Conservation Plan for Seabirds

Affected interests

TABLE 4 Affected interests and their contribution to the wildlife conservation plan

Wildlife Conservation Plan for Seabirds 49

TABLE 4 Affected interests and their contribution to the wildlife conservation plan continued View image in the official source

50 Wildlife Conservation Plan for Seabirds

Chapter 9 Evaluation the performance of the plan

This plan must be formally reviewed no later than five years from when it was endorsed and made publicly available. The review will determine the performance of the plan; whether the plan continues unchanged; whether the plan is varied to remove completed actions and include new conservation priorities; or whether a wildlife conservation plan is no longer necessary for the species.

The review will be coordinated by the Department of Agriculture, Water and the Environment in association with relevant state and territory agencies, and key stakeholder groups including scientific research organisations.

Wildlife Conservation Plan for Seabirds 51

Chapter 10 Major benefits to other migratory species, marine species, species of cetacean or conservation dependent species

There are 37 seabirds that are currently listed threatened under the EPBC Act.

To promote the recovery of listed threatened species, conservation advices and

where required, recovery plans, are made or adopted in accordance with Part 13 of the EPBC Act. Conservation advices provide guidance at the time of listing on known threats and priority recovery actions that can be undertaken at a local and regional level. Recovery plans describe key threats and identify specific recovery actions that can be undertaken to enable recovery activities to occur within a planned and logical national framework. The implementation of this Plan will benefit a number of threatened species and their habitats. Below is a table of threatened seabirds in Australia, and links to their approved conservation advice and/or recovery plans.

While the Wildlife Conservation Plan for Seabirds focuses on identifying and developing effective management strategies for important habitats, there are also major conservation benefits for those species that share habitats with seabirds. There are a number of major benefits to species other than seabirds that may result from implementation of this Plan. For example, Hooded Plover (Thinornis cucullatus cucullatus) listed as vulnerable under the EPBC Act, shares similar habitat requirements with listed seabirds, as do nesting marine turtles in Western Australia, Northern Territory, Queensland and Commonwealth marine areas, and may all benefit from habitat management actions. While coastal and freshwater or coastal wetlands serve as nurseries for many prey species of fish and aquatic invertebrates.

There are at least 18 species of resident shorebirds including the Banded Stilt (Cladorhynchus leucocephalus), Hooded Plover (Thinornis cucullatus) and Australian Pied Oystercatcher (Haematopus longirostris) that share many habitat requirements and would also gain major benefits from the Plan’s implementation.

52 Wildlife Conservation Plan for Seabirds

Major benefits to other migratory species, marine species, species of cetacean or conservation dependent species

View image in the official source

Wildlife Conservation Plan for Seabirds 53

Chapter 11 Species profilesRed-tailed Tropicbird (Phaethon rubricauda)

TABLE Species information for the Table Red-tailed Tropicbird (Phaethon rubricauda)

The Red-tailed Tropicbird (Phaethon rubricauda) is a medium sized, oceanic, Indo-Pacific Ocean seabird. Adults are mainly white with bright red bill and very long central rectrices. Sexes are similar with no seasonal plumage changes. At sea, the species is solitary, flying mostly well above the waves with regular, mechanical wing-beats alternating with horizontal glides. The species breeds in tropical and subtropical zones on volcanic and other islands, stacks, atolls, cays away from mainland areas. Nests are located in rugged terrain, on coastal cliffs and slopes but also on cays, at the base of trees with dense leaf canopy that reaches the ground, and coral atolls. Most food is captured by deep plunging vertically into the water. Their diet mainly consists of fish and cephalopods. Movements away from the breeding site are not well known but adults and juveniles appear to disperse widely.

The global population is estimated at >32,000 individuals (del Hoyo et al. 1992). The Australian population is poorly known owing to the numerous breeding sites and protracted and asynchronous breeding season making an accurate census difficult. The largest population breeds on Christmas Island (>2,000 pairs) with additional key breeding locations on Cocos (Keeling) Group, islands of Ashmore Reef Marine Park, Lord Howe Island, Norfolk Island, Coral Sea Marine Park and two known islands and cays in the Great Barrier Reef Marine Park. The Herald Cays (Coral Sea Marine Park) support a population in excess of 500 breeding pairs and is the most important breeding site for this species in Eastern Australia (Baker 2008). The population of Red-tailed Tropicbirds on Raine Island, Queensland has increased on average, by approximately 1.4 per cent per year since 1980 (GBRMPA 2019). The national population is suspected to be stable in the absence of evidence for any declines or substantial threats.

54 Wildlife Conservation Plan for Seabirds

Invasive species, particularly rats and cats, have caused significant losses in Red-tailed Tropicbird colonies. The species has been shown to benefit from eradications that have been carried out to date. An increased frequency and intensity of tropical storm and cyclones may reduce breeding success. Sea level rise has the potential to eliminate breeding habitat on low lying islands and cays.

 Determine Red-tailed Tropicbird breeding population numbers and trends

 Manage human disturbance at breeding localities, particularly when adults are incubating eggs

 Control, or eradicate invasive species at breeding localities

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

Photograph of a Red-tailed Tropicbird flying in blue sky and clouds

Wildlife Conservation Plan for Seabirds 55

White-tailed Tropicbird (Phaethon lepturus)

TABLE Species information for the Table White-tailed Tropicbird ((Phaethon lepturus)

The White-tailed Tropicbird (Phaethon lepturus) is a distinctive, medium sized white seabird with black diagonal bar on the inner upperwing, black based outer primaries and long white central tail feathers and yellow bill. It is much smaller than the Red-tailed Tropicbird. The species is pantropical, breeding at many locations, though usually in low numbers. Two subspecies occur in Australia, subspecies fulvus is listed endangered under the EPBC Act. The species is most common off North West Australia and a rare visitor to the Coral Sea and east coast. The species is primarily oceanic in tropical waters, rarely inshore, and only is near land when breeding. Nests are located on islands and atolls utilising a variety of habitats from closed canopy rainforest to bare sandy ground and rugged rocky terrain. The species feeds mainly on fish and cephalopods, captured by deep plunge diving. Patterns of movement away from the breeding sites is not well known.

The global population is estimated at >50,000 individuals (del Hoyo et al. 1992). The Australian population is poorly known owing to the numerous breeding sites and protracted and asynchronous breeding season making an accurate census difficult. The largest population breeds on Christmas Island (6,000–12,000 pairs; subspecies fulvus) and is believed to be in decline with additional breeding locations on Cocos (Keeling) Group and islands of Ashmore Reef Marine Park (subspecies lepturus).

Cyclones and tropical storms have been known to cause high levels of mortality of both chicks and brooding adults. Habitat affected by the storms may also render nesting sites temporarily unusable. The species readily adapts to artificial nesting sites and studies show that it can increase nesting success when compared to natural nests. Invasive species, particular rats and cats, have caused significant losses in White-tailed Tropicbird colonies. Invasive plants can render nest sites unsuitable. Tropicbirds are vulnerable to oil pollution at sea.

 Determine White-tailed Tropicbird breeding population numbers and trends

 Trial artificial nesting shelters to improve nesting success in disturbed habitats

 Control, or eradicate invasive species at breeding localities

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

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Matsudaira’s Storm-petrel (Hydrobates matsudairae)

TABLE Species information for Matsudaira's Storm-petrel

The Matsudaira’s Storm-petrel (Hyrobates matsudairae) is a dark-brown storm-petrel with long angular wings. Tail is long and forked. The species occupies a small

breeding range in southern Japan, probably only two islands. It is known to breed on Minami-Iwo-Jima, and perhaps on Kita-Iwo-Jima. It has also been recorded around Ogasawara Islands and it is assumed to breed there but required confirmation. The species is a colonial breeder, nesting in burrows on high ground. Breeding is thought to begin in January, with most young fledging by June. After the breeding season, birds move south to the Timor Sea, north-west Australia and into the northern Indian Ocean. During the non-breeding season Matsudaira’s Storm-petrel remains in oceanic waters far from the coast.

No quantitative data are available on the species population, although it is reported to be locally common in its breeding range and its abundance in the Indian Ocean has led to the suggestion that the global population is at least 20,000 individuals. The population trend is difficult to determine because of uncertainty over the main threats to the species. The species has been assessed as globally vulnerable under IUCN criteria on the basis that it occupies a small range when breeding and is susceptible to stochastic events and human impacts.

Black Rats (Rattus rattus) became established on Kita-Iwo-Jima apparently following the Second World War and are considered to have caused local extirpations. There does not appear to be any recent breeding records from the island. Rats pose a threat to birds attempting to recolonise the island. A greater threat would be the introduction of rats to the only known breeding island, Minami-Iwo-Jima. Storm-petrels are known to be vulnerable to oil pollution at sea and marine debris.

 Gain an improved understanding of at sea distribution in north west Australia

 Exchange information on successful Rattus spp. eradiation techniques with Japanese authorities

 Facilitate the collaboration between Australian and Japanese researchers to survey and monitor known colonies, study ecological requirements, search for undocumented breeding colonies in suitable habitat

Wildlife Conservation Plan for Seabirds 57

Swinhoe’s Storm-petrel (Hydrobates monorhis)

TABLE Species information for the Swinhoe's Storm-petrel (Hydrobates monorhis)

Swinhoe’s Storm-petrel (Hydrobates monorhis) is a small dark brown seabird that has a fluttering flight. The species can be found over oceanic and inshore waters. The species breeds on islands in the north-west Pacific Ocean off Russia, Japan, the Republic of Korea and China. Breeding starts in April forming loose colonies close to the sea in rock crevices and lays a single egg. The species is strictly nocturnal at the breeding sites to avoid predation by gulls and skuas. Outside the breeding season the species migrates into the Indian Ocean and Arabian Sea.

Based on estimates of Brooke (2004) and Sato et al. (2010) the global estimate of the species is estimated between 65,000 – 260,000 mature individuals. Birds Korea (2010) estimated that 100,000 pairs nest on Gugeul Islet, Republic of Korea which if accurate, suggests that one island holds a significant proportion of the global population. Little is known about the Chinese breeding population. The Australian population is poorly known owing to the oceanic nature of the species.

The species is listed as globally near threatened based on IUCN criteria, on the basis that its population is expected to undergo a moderately rapid decline over the next three generations, owing to the impacts of introduced species and anthropogenic disturbance.

Swinhoe’s Storm-petrel is threatened by a number of invasive species, including Brown Rats (Rattus norvegicus) and Oriental Chaff Flower (Achyranthes japonica) in Japan and the Republic of Korea. The seeds of the invasive plant represent an entrapment risk, particularly for adults. There has been a decrease in the population of Swinhoe’s Strom-petrels in Japan. Colonies have been adversely affected by mining activities and anthropogenic disturbance. The breeding population on Verkhovsky Island, Russia is likely threatened by recreational users in summer months.

 Gain an improved understanding of at sea distribution in north west Australia

 Exchange information on successful Rattus spp. eradiation techniques with Korean and Japanese authorities

 Facilitate the collaboration between Australian, Korean and Japanese researchers to survey and monitor known colonies, study ecological requirements, search for undocumented breeding colonies in suitable habitat

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Species profilesView image in the official source

Wilson’s Storm-petrel (Oceanites oceanicus)

TABLE Species information for the Wilson's Storm-petrel (Oceanites oceanicus)

Wilson’s Storm-petrel (Oceanites oceanicus) is a small blackish storm-petrel with proportionately short rounded wings, square tail and long thin legs. In flight, feet usually project well beyond the tail. This species has an extremely large range, but most often seen over continental shelf waters. The breeding range of Wilson’s Storm-petrels includes subantarctic islands from Cape Horn (Chile) east to the Kerguelen Islands (French Southern Territories), Macquarie Island, Heard Island and coastal Antarctica. The species undergoes a trans-equatorial migration, spending the nonbreeding season in the north Atlantic and north Indian Oceans. A number of individuals also migrate into the North Pacific Ocean. The species breeds in rocky crevices, on cliffs and amongst boulder scree. It feeds in cold waters with a diet comprised of planktonic crustaceans (especially krill) and fish.

Brooke (2004) estimated the global breeding population to number 4–10 million breeding pairs. The Australian population is poorly known owing to their small size and their cryptic nature on land. A couple of pairs of Wilson’s Storm-petrel were detected in 1993 at Bishop and Clerk Island (Brothers and Ledingham 2008) and are also likely to be breeding on Macquarie Island (Tasmanian Parks and Wildlife Service unpublished data). In the absence of reliable population data, their current population trend is unknown.

The species is vulnerable from invasive species. On the Kerguelen and Crozet Islands, rats are reported to take chicks and eggs, causing nest failure. Cats may take adults in addition to chicks. Storm-petrels are known to be vulnerable to oil pollution at sea and marine debris.

 Gain an improved understanding of at sea distribution in Australia

Grey-backed Storm-petrel (Garrodia nereis)View image in the official source

TABLE Species information for the Grey-backed Storm-petrel (Garrodia nereis)

The Grey-backed Storm-petrel (Garrodia nereis) is the smallest storm-petrel in the Southern Ocean. At sea, the species appears as a tiny, fast flying storm-petrel with a small and slender body and square cut tail. The species has a circumpolar distribution in the subantarctic, breeding on islands from the Falkland Islands (Islas Malvinas) in the south-west Atlantic Ocean east to the Chatham Islands, New Zealand. The species breeds on Macquarie Island and is considered a non-breeding bird at Heard Island. Grey-backed Storm-petrels winter off the southern coast of Argentina and Australia. Its diet comprises mainly of immature barnacles and other crustaceans, but also small squid and occasionally small fish. It catches prey mostly by pattering over the surface whilst in flight, but also by dipping and shallow plunging. It has been seen to attend trawlers and occasionally follows ships. Its breeding season starts in October or November, with individuals forming loose colonies creating burrows in vegetation or nesting in crevices in rocks.

The population is not well known however, Brooke (2004) estimated the global population to potentially number over 200,000 individuals. The Australian population is unknown. The population is suspected to be in decreasing owing to predation by invasive species.

Grey-backed Storm-petrels are at risk of predation by invasive species such as rats. Tussock grassland on some breeding islands have been modified by grazing by invasive species and fire. A number of individuals are killed each year due to light-induced collisions with boats. Storm-petrels are known to be vulnerable to oil pollution at sea and marine debris.

 Confirm breeding on Macquarie Island

 Mitigate against impacts of light pollution by boats at sea

White-faced Storm-petrel (Pelagodroma marina)

TABLE Species information for the White-faced Storm-petrel (Pelagodroma marina)

The White-faced Storm-petrel (Pelagodroma marina) is a medium sized, distinctively patterned storm-petrel, common over inshore and oceanic waters around southern Australia. The species has an extremely large range and breeds on remote islands in the North and South Atlantic Ocean and on the coast of southern Australia and New Zealand. Outside the breeding season the Australian population range as far as the northern Indian Ocean and the north-west coast of South America. The species can normally be found over oceanic waters except when close to breeding colonies. The species feeds mostly on planktonic crustaceans and small fish. It feeds mainly of the wing by pattering and dipping. The species rarely follows ships but is known to follow cetaceans. White-faced Storm-petrels generally breed in colonies during spring and summer, forming burrows in flat areas with low herbaceous vegetation but also in rocky areas and on slops. The species is migratory, moving from temperate breeding areas to tropical and subtropical waters.

Brooke (2004) estimated the global population to number at least 4 million individuals. The European population is estimated at 77,000–111,000 pairs and is estimated to have decreased by less than 25 per cent in 46 years (three generations). In NSW the species may have declined by as much as 85 per cent since the 1970s but precise data from initial surveys is lacking (N. Carlile pers. comm). The Australian population is unknown. The population is suspected to be in decreasing owing to predation by invasive species.

The species is threatened by invasive species such as rabbits, rats, mice and cats. Expanding Silver Gull (Chroicocephalus novaehollandiae) breeding colonies have been attributed to the decrease of some White-faced Storm-petrel colonies following shifts in the vegetation community composition and erosion. Spiny woody weed infestations (i.e. Boxthorn Lycium chinense) may impact on nest sites, restricted access and cause impalement (Sir Joseph Banks Group, SA). Fires can adversely affect vegetation on breeding islands.

 Survey and quantify breeding colonies in Australia.

 Regularly monitor breeding colonies and reproductive success, particularly in the presence of Silver Gull breeding colonies

 Control, or eradicate invasive species from known (and former) breeding islands

 Establish new breeding colonies

 Mitigate against impacts of light pollution around breeding colonies

Wildlife Conservation Plan for Seabirds 61

Black-bellied Storm-petrel (Fregetta tropica)

TABLE Species information for the Black-bellied Storm-petrel (Fregetta tropica)

The Black-bellied Storm-petrel (Fregetta tropica) is a medium sized storm-petrel with conspicuous white sides to the abdomen, central underwings, flanks and rump. The species breeds on subantarctic islands and migrates to subtropical and tropical zones of the Atlantic, Indian and Pacific Oceans, regularly occurring north to the Equator. Its breeding season begins in November, when it forms loose colonies on bare rocky slopes, in vegetation or peat of offshore islands or stacks. The species may be associated with cool water currents where it feeds on squid and small fish.

Brooke (2004) estimated the global population to number 500,000 individuals. The Australian population is unknown.

Black-bellied Storm-petrels are at risk of predation by invasive species such as rats.

A number of individuals are killed each year due to light-induced collisions with boats.

Storm-petrels are known to be vulnerable to oil pollution and marine debris.

 Determine the relationship between breeding distribution and existing and projected marine productivity for Australian taxa

 Mitigate against impacts of light pollution by boats at sea

Photograph of a Black-bellied Storm Petrel flying low

62 Wildlife Conservation Plan for Seabirds

Cape Petrel (Daption capense)

TABLE Species information for the Cape Petrel (Daption capense)

View image in the official sourceView image in the official source

The Cape Petrel (Daption capense) is a distinctive, medium-sized, stockily built petrel with strikingly chequered and patterned black and white upperparts. The species has an extremely large range covering the entire Southern Ocean. The Cape Petrel is oceanic, occurring mainly over cold waters beyond the continental shelf but can be found over inshore waters during the breeding season. The main breeding grounds are on Antarctic and sub-Antarctic islands, including Auckland, Chatham and Campbell Islands. The breeding season starts in November with colonies of variable sizes being formed on cliffs or steep rocky slopes. It nests in shallow crevices, in scrape on rocky ledges, on stable beds of gravel or among boulders. During the breeding season, Cape Petrels feed predominately around Antarctica and the sub-Antarctic islands. Its diet comprises mainly of krill, but also fish, squid, offal, carrion and refuse from ships, acquiring food by hydroplaning, dipping whilst on the wing and surface diving. Cape Petrels are known to associate with whales and other seabirds and congregate in large flocks around trawlers.

The global population is thought to exceed 2 million individuals (Brooke 2004). In the 1980s, the New Zealand breeding population was estimated to be between 5,000–10,000 pairs (Robertson and Bell 1984). There is a small breeding population at Macquarie Island, likely to be increasing at Macquarie Island after the successful Macquarie Island Pest Eradication Project (DPIPWE pers. comm). In 2003/04, breeding estimates from Heard Island are between 1,000–2,500 pairs (E. Woehler pers. comm). The population is suspected to be stable in the absence of evidence for any decreases or substantial threats.

Cape Petrels are known to be adversely impacted by invasive species on breeding islands. Ingestion of marine debris may impact some individuals.

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

Wildlife Conservation Plan for Seabirds 63

Broad-billed Prion (Pachyptila vittata)

TABLE Species information for the Broad-billed Prion (Pachyptila vittata)

The Broad-billed Prion (Pachyptila vittata) is the largest prion with a large, broad, glossy iron grey bill, high forehead, sombre facial pattern and prominent blue-grey collar impart appearance of large dark head compared to other prions. The species has an extremely large range extending from the Southern Ocean to the South Atlantic Ocean. The species breeds on Gough Island and Tristan da Cunha in the south Atlantic Ocean and on the Chatham Islands, New Zealand. Breeding starts in July or August and individuals are strongly colonial, nesting in burrows which are sometimes occupied by more than one pair. Broad-billed Prions breed on a variety of substrates and areas including, coastal slopes, flat lava fields, offshore islets and cliffs, dry rocky soil, caves and scree. Adults are thought to remain in waters adjacent to breeding colonies, however, young birds seem to occur farther north to Australia and South Africa. The diet of this species is comprised mostly of crustaceans (especially copepods), squid and some fish. The species apparently takes more crustaceans in summer and small squid in winter. Prey is obtained usually by hydroplaning and by filtering or surface seizing.

The global population has been estimated to exceed 15 million individuals (Brooke 2004). The population is suspected to be decreasing owing to predation from invasive species.

The main threats faced by the Broad-billed Prion come from introduced

predators. House Mice (Mus musculus) on Gough Island are adversely impacting reproductive success and causing very rapid population decreases (Cuthbert et al. 2013, Dilley et al. 2015). Estimates of breeding success were only 6 per cent from the 2009-10 and 2010-11 breeding seasons (Cuthbert et al. 2013), and chick mortality in 2014 was 100 per cent (Dilley et al. 2015). The population by 2000-01 had already been estimated to have reduced by more than 80 per cent since the 1960s (Carboneras et al. 2018). In New Zealand, rapid decreases and local extirpations have occurred following the introduction of other invasive predators to breeding islands, including rats and stoats in Dusky Sound, Fiordland, cats (Felis catus) on Herekopare Island and Weka (Gallirallus australis) on Jacky Lee Island (Miskelly 2013). Severe weather events also pose a threat. A severe storm in 2010 caused considerable mortality on breeding islands around Stewart Island, New Zealand (Miskelly 2013), and predicted increases in the frequency and intensity of storms may impact part of the population sufficiently to impact the global abundance of the species.

64 Wildlife Conservation Plan for Seabirds

Salvin’s Prion (Pachyptila salvini)

TABLE Species information for the Salvin's Prion

Salvin’s Prion (Pachyptila salvini) is a medium sized prion of the Indian Ocean. The species is very similar to Antarctic Prion (P. desolata) in shape, size, appearance and habits making the two species difficult to separate at sea. The species has an extremely large range which extends from South Africa to Australian and New Zealand. This species normally occurs offshore and can be found in areas of upwelling outside the breeding season. The species breeds on the Prince Edwards Islands (South Africa), Crozet Islands, Amsterdam Islands and St Paul Island (French Southern Territories). Breeding starts in October in huge colonies up to and above one million individuals. It nests in burrows, usually on islands, inland on highland plateau or on slopes with grass or shrubs. It can also be found in caves or crevices (del Hoyo et al. 1992). Its diet is comprised mostly of crustaceans, especially krill, but also fish and squid, all of which it catches either by hydroplaning, surface-seizing or filtering.

Brooke (2004) estimated the global population to exceed 12 million individuals. The population is suspected to be stable in the absence of evidence from any decreases or substantial threats.

Black Rats (Rattus rattus) have had a considerable impact on colonies in the past, causing them to shift to locations above the tree-line, and are likely to still be causing decreases within the very large breeding colonies. Cats also have some effect and are present on Cochons Island but are too large to enter burrows although it is thought that predation of adults occurs along with that of near-fledged chicks (del Hoyo et al. 2019).

Wildlife Conservation Plan for Seabirds 65

Antarctic Prion (Pachyptila desolata)

TABLE Species information for the Antarctic Prion (Pachyptila desolata)

The Antarctic Prion (Pachyptila desolata) is an abundant, medium sized prion of Antarctic and subantarctic waters, ranging into subtropical waters. The species is very similar to Salvin’s Prion (P. salvini) from which it is difficult to distinguish at sea. The species has an extremely large range and occurs in the Indian, Southern and Atlantic Oceans. The Antarctic Prion breeds on islands in the southern oceans, including the Crozet Islands and Kerguelen Island (French Southern Territories), Macquarie Island and Heard Island (Australia), the Auckland Islands (New Zealand), South Georgia (Georgias del Sur), the South Sandwich Islands (Islas Sandwich del Sur), Scott Island and the Scotia Archipelago. All birds leave the colonies after breeding, dispersing from pack ice in Antarctica to as far north as Peru, and also occurring off South Africa and Australia. This species breeds on slopes under grass tussocks, in rock crevices or scree, or on cliffs. Its prey is mostly crustaceans (especially krill, copepods and amphipods), but also small quantities of fish and squid (del Hoyo et al. 1992).

Brooke (2004) estimated the global population to number 50 million individuals. The breeding population on Macquarie and Heard Islands has not been quantified for some time. On Macquarie Island, abundance was estimated at approx. 49,000 pairs from surveys conducted between 1975 and 1982 (Brothers 1984, Tasmanian Parks and Wildlife Service 2006). Results are pending from the most recent island population census undertaken in 2018 (University of Queensland and Tasmanian Parks and Wildlife Service unpublished data). On Heard Island the population was estimated at 100,000 pairs in 2003/04 (Woehler 2006, 2010). The population is suspected to be in decreasing at some (non-Australian) sites as a result of predation by invasive species, however, is likely to be increasing at Macquarie Island after the successful eradication of introduced rodent predators during the Macquarie Island Pest Eradication Project (DPIPWE pers. comm.).

This species is decreasing at some sites due to a number of invasive species.

The Antarctic Prion appeared to be unable to successfully nest in the presence of Brown Rats on South Georgia, and possibly in other parts of the range (Marchant and Higgins 1990). Feral pigs and cats are known to kill large numbers on the Auckland Islands. The population on Macquarie Islands is expected to increase as a result of eradication efforts of invasive species.

 Consolidate current population data from Macquarie Island

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

66 Wildlife Conservation Plan for Seabirds

Slender-billed Prion (Pachyptila belcheri)

TABLE Species information for the Slender-billed Prion (Pachyptila belcheri)

The Slender-billed Prion (Pachyptila belcheri) is a small, pale prion of Antarctic and subantarctic waters. It can be distinguished from other prions by the small head, slender body and slender bluish bill, mostly white lores and broad white supercilium giving a striking pale-face appearance. The species has an extremely large range. The Slender-billed Prion breeds in the Crozet Islands and the Kerguelen Islands (French Southern Territories), the Falkland Islands (Islas Malvinas) and Noir Island, Chile. The species possibly breeds on Macquarie Island. Outside the breeding season it can be found over much of the Southern Ocean, including the coasts of South Africa, Australia and South America as far north as Uruguay and southern Peru. The species can usually be found over oceanic waters but will feed inshore or in shallow offshore waters during the breeding season. It feeds mostly on crustaceans with a high dependence on amphipods but can also take small fish and squid. It catches prey mainly by surface-seizing, dipping and pattering at night. Breeding starts in October in loose colonies in coastal areas with soft or stony soil and low vegetation. It nests in burrows in soft soil or under rocks (del Hoyo et al. 1992).

Brooke (2004) estimated the global population to number at least 7 million individuals. The Australian population is unknown. The population is suspected to be stable in the absence of evidence for any decreases or substantial threats.

The largest colony of Slender-billed Prion, on New Island in the Falklands, has suffered predation from cats (Felis catus) and rats, but appears naturally resilient to this pressure (Hilton and Cuthbert 2017) and eradications have further nullified any population impacts (del Hoyo et al. 2019). Cat predation is however ongoing on Iles Kerguelen, and may be having impacts here alongside predation from skuas on non-breeding birds (del Hoyo et al. 2019).

 Determine breeding status on Macquarie Island

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

Wildlife Conservation Plan for Seabirds 67

Fairy Prion (Pachyptila turtur)

View image in the official source

TABLE Species information for the Fairy Prion (Pachyptila turtur)

The Fairy Prion (Pachyptila turtur) is small, circumpolar prion frequenting subantarctic and subtropical waters. The species has a rounded crown, rounded wings and a fairly long wedge-shaped tail. At sea it may be confused with Fulmar Prion (P. crassirostris). Two subspecies breed in Australia, turtur and subantarctica. The subspecies subantarctica has previously been detected breeding on two rock stacks off Macquarie Island in 1979 (Brothers 1984) and Bishop and Clerk Island in 1993 (Brothers and Ledingham 2008) and is listed as vulnerable under the EPBC Act. Fairy Prions can be found breeding on the Chatham Islands, Snares Islands and Antipodes Islands of New Zealand, islands around Tasmania, including the Bass Strait Islands of Australia, the Crozet Islands (French Southern Territories) in the south Indian Ocean and the Falkland Islands (Islas Malvinas) and South Georgia (Georgia del Sur) in the South Atlantic (del Hoyo et al. 1992). The breeding season starts in September and the species is highly colonial, creating burrows in coastal sites on oceanic islands (del Hoyo et al. 1992). The species occurs mainly offshore but may move inshore during stormy weather. Its diet is comprised mostly of crustaceans (especially krill), but occasionally includes some fish and squid. It feeds mainly by surface-seizing and dipping but can also

catch prey by surface-plunging or pattering. It often associates with other prions and storm-petrels when feeding around boats.

Brooke (2004) estimated the global population to number around 5 million individuals. The Australian breeding population and trends are unknown. The subspecies subantarctica is thought to number as few as 50 pairs (Brothers 1984) but is expected to increase with the successful eradication of Black Rats (Rattus rattus) from

Macquarie Island where it may recolonise the main island. The population status of P. turtur at breeding locations around Tasmania (e.g. Port Davey islands, Maatsuyker Island group, Tasman Island, and islands in Bass Strait including Albatross Island and Black Pyramid) is unknown. The global population of P. turtur is suspected to be stable in the absence of evidence of any population decreases or substantial threats.

Although the Fairy Prion is not thought to be experiencing any significant threats across the majority of its range, the population in the Kerguelen Islands suffers ongoing predation from cats. The removal of cats from Tasman Island in Tasmania in 2010/11 has resulted in a population increase on that island (Tasmanian Parks and Wildlife Service, unpublished data). Procellariiform seabirds are have the highest incidence of marine debris ingestion so may be susceptible to plastic ingestion.

 Survey and regularly monitor breeding populations at index locations

 Determine breeding parameters for this species in Australia

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

Wildlife Conservation Plan for Seabirds 69

Fulmar Prion (Pachyptila crassirostris)

TABLE Species information for the Fulmar Prion (Pachyptila crassirostris)

The Fulmar Prion (Pachyptila crassirostris) is a relatively rare prion similar in size and

appearance to the more abundant Fairy Prion (P. turtur). The Fulmar Prion is oceanic

and stays over the southern oceans close to colonies. When breeding, birds come ashore

and nest on Heard Island (Australia; subspecies eatoni) in the south Indian Ocean,

and the Auckland Islands, Chatham Islands, Bounty Island and Snares Island off the

coast of New Zealand (subspecies crassirostris). Breeding occurs in colonies starting

in October, nesting on coastal cliffs and boulder slopes in rock crevices and cracks

(del Hoyo et al. 1992). Little else is known about the breeding ecology of the species.

Its diet comprises mostly of crustaceans but fish, squid and molluscs are also taken.

The global population is estimated to be between 150,000–300,000 individuals (Brooke 2004). The population on Heard Island is estimated to be at least 10,000 breeding pairs (Woehler 2006, 2010). The population is suspected to be stable in the absence of evidence of any decrease or substantial threats.

On Auckland Island, predation by Cats (Felis catus), dogs (Canis familiaris) and pigs (Sus domesticus) is thought to be impacting the breeding population, and on other islands the presence of invasive species may be prohibiting establishment (or re-establishment). Information is poor on the degree to which the species is affected and there is some concern that impacts in some colonies may be severe. The introduction of predators to Heard Island is a plausible threat (Garnett et al 2011).

 Study the breeding biology of the species

 Implement best practice quarantine measures at breeding colonies to reduce the risk of any invasive species (re)establishing on islands

70 Wildlife Conservation Plan for Seabirds

Bulwer’s Petrel (Bulweria bulwerii)

TABLE Species information for the Bulwer's Petrel (Bulweria bulwerii)

Bulwer’s Petrel (Bulweria bulwerii) is a small all-dark petrel similar in size to small gadfly petrels (Pterodroma spp.) and prions (Pachyptila spp.) with strikingly long wings and long wedge-shaped tail. The species is pantropical, being found in all three oceans outside the breeding season. Breeding sites include the eastern Atlantic from the Azores, Portugal to Cape Verde, and the Pacific from eastern China and the Bonin Islands (Japan), east to the Hawaiian Islands (USA), and the Marquesas Islands (French Polynesia) (del Hoyo et al. 1992). The breeding season begins in April or May, with individuals forming colonies in a wide variety of habitats on offshore islands. Nests are usually in burrows, crevices, cracks or caves, under debris or vegetation cover (del Hoyo et al. 1992). After breeding, Bulwer’s Petrel migrate away from colonies but movements are not well understood. Birds are seen off north-west Australia between September and April and are thought to be on migration into the Indian Ocean. The diet comprises mainly of fish and squid, with minor proportions of crustaceans and sea-striders, feeding largely at night by surface-seizing.

Brooke (2004) estimated the global population to number between 500,000–1 million individuals. The Australian population is unknown but observations have increased off north-west Australia, Christmas Island and the islands of Ashmore Reef in recent decades. The population is suspected to be stable in the absence of evidence of any decreases or substantial threats.

Predation by cats (Felis catus) and Black Rats (Rattus rattus) occurs over portions of the breeding range (Cabral et al. 2005, Matias et al. 2009). Feral cats are considered a major driver of the present distribution of the species, on the Azores where breeding areas are restricted to steep cliffs. Black Rats are present on many of the islands on which the species breeds or would be likely to breed, and, along with cats, is thought to be one of the main determinants of the current breeding distribution. The species may be at risk of incidental capture in longline fisheries, but as yet, no significant effects of bycatch on adult mortality have been documented (Waugh et al. 2012). Due to the species foraging habit and wide range overlapping with commercial fishing areas, it is thought to suffer a heightened risk of mortality from oil spills and other marine pollution. Light pollution at night may be an important cause of mortality in some areas, and tourism and recreational developments may reduce available habitat in breeding colonies (del Hoyo et al. 2019).

Wildlife Conservation Plan for Seabirds 71

Wedge-tailed Shearwater (Ardenna pacifica)

TABLE Species information for the Wedge-tailed Shearwater (Ardenna pacifica)

The Wedge-tailed Shearwater (Ardenna pacifica) is a large, lightly built polymorphic shearwater found in the subtropical and tropical Pacific and Indian Oceans between latitudes 35°N and 35°S. The species closely resembles Buller’s Shearwater (A. bulleri) in size and shape. The species occurs in a wide variety of marine habitats, from well inshore to shelf-edge and oceanic waters. Numerous breeding colonies occur on offshore islands along the Western Australian coast, New South Wales and on islands and cays in the Great Barrier Reef, particularly the Capricorn – Bunker Group. Large numbers breed on islands in the Coral Sea Marine Park. The species also breeds on Cocos (Keeling), West Island of Ashmore Marine Park, Lord Howe and Norfolk Islands. It feeds mostly on fish, with some cephalopods and crustaceans. It catches prey mainly on the wing by dipping but also by surface-seizing or pursuit-plunging. Usually solitary or in small parties at sea, but often in large feeding flocks with other species, particularly Sooty Tern (Onychoprion fuscata) and Common Noddy (Anous stolidus). The species will congregate around schooling fish and will often attend trawlers and smaller fishing boats.

Brooke (2004) estimated the global population to number >5,200,000 individuals. Australia hosts a large proportion of the global population with approximately 1.1 million pairs breeding in Western Australia (Burbidge et al. 1996) and 560,000 breeding pairs in the Capricorn – Bunker Group, where 95 per cent of the Queensland population occur (Dyer et al 2005). Monitoring data by QPWS&P at Capricornia Cays indicate that there has been almost 40 per cent decline in Wedge-tailed Shearwater population of a 15 year period. Total estimates for North West Island, Heron Island Mast Head and Lady Musgrave in across the 1996-2000 period was 528,909 pairs. Populations of Wedge-tailed Shearwater had declined to 338,836 pairs by 2012–2015 survey period (Hemson 2015). There is no indication that the Capricorn Cays Wedge-tailed Shearwater population has begun to recover. The global population is suspected to be in decreasing but no trend data are available.