62Wildlife Conservation Plan for Seabirds

62 Wildlife Conservation Plan for Seabirds

Cape Petrel (Daption capense)

TABLE Species information for the Cape Petrel (Daption capense)

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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.