106Wildlife Conservation Plan for Seabirds

106 Wildlife Conservation Plan for Seabirds

Climate change is an important candidate for explaining recent decreases at some breeding sites. Large-scale environmental changes, particularly those related to sea surface temperatures could be contributing to habitat loss, indirect ecosystem effects, direct species mortality and reduced reproductive success, but the nature and level of impacts remain unclear as there may be divergent responses in different populations; climate was found to be have potentially positive effects in the short to medium term for the population studied at Bird Island, South Georgia, whereas changes to predation dynamics appear to be the main factor driving decreases (Horswill et al. 2014, 2016).

Commercial fisheries could represent a potential threat through incidental capture and resource competition. Long-line fisheries at winter feeding grounds have inflicted limited bycatch mortality on Macaroni Penguins (Dyer and Crawford 2015) and harvesting of Antarctic krill (Euphausia superba) could reduce food availability if management does not adequately allow for the dietary needs of the species.

Invasive mammals including cats, mice and rabbits are present on a number of subantarctic islands but their current impact on the species is thought to be negligible (Crossin et al. 2013). Breeding colonies on Marion Island have decreased following outbreaks of avian cholera and other unknown diseases (Cooper et al. 2009, Grimaldi et al. 2011).

Human impacts potentially also include disturbance from tourists, scientists and construction of new infrastructure. Protection of habitat on land and at sea remains important, with the designation of appropriate protection for transit, foraging and rafting areas at sea.

 Quantify the breeding population on Heard and McDonald Islands

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

Photograph of a group of Macaroni Penguins on rocks

Wildlife Conservation Plan for Seabirds 107

Little Penguin (Eudyptula minor)

TABLE Species information for the Little Penguin (Eudyptula minor)

The Little Penguin (Eudyptula minor) is the smallest penguin species and is endemic to Australia and New Zealand. In Australia, the species occurs from Western Australia (Carnac Island) to New South Wales (Broughton Island) and Tasmania. The distribution is not continuous, with sections of the southern coast of Australia without occurrence of breeding colonies. In New Zealand, Little Penguins occur from the Chatham Islands to mainland New Zealand, including Stewart Island. The Little Penguin breeds during the austral autumn to summer months and are the only truly nocturnal penguin species on land; adults always arrive after dusk and leave before dawn (Klomp and Wooller 1991, Chiaradia et al. 2007, Rodriguez et al. 2016). Little Penguins typically lay two eggs per clutch (Dann 2013). This species is a generalist feeder, with large variability in diet amongst colonies and even between years at the same colony (Klomp and Wooller 1988; Gales and Pemberton 1990, Cullen et al. 1992, Fraser and Lalas 2004, Chiaradia et al. 2010, 2012). They feed mainly on clupeids, such as anchovy Engraulis austalis and sardines Sardinops sagax, when feeding chicks, but they may also feed on krill Nyctiphanes australis and several species of cephalopods at all stages of breeding (Gales and Pemberton 1990, Cullen et al. 1992, Chiaradia et al. 2012). When foraging, some individuals can take advantage of man-made features, like ship channels to aid in their foraging (Preston et al. 2008).