64Wildlife Conservation Plan for Seabirds

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).