Brown petrel, Pediunker, Grey shearwater
The grey petrel (Procellaria cinerea ), also called the brown petrel, pediunker or grey shearwater is a species of seabird in the Procellariidae, or petrel family. It is pelagic and occurs in the open seas of the Southern Hemisphere, mainly between 32°S and 58°S.
The grey petrel is a large grey, white, and brown petrel. It averages 50 cm (20 in) in length, 115–130 cm (45–51 in) in wingspan and weighs around 1,000 g (35 oz). It has a brownish-grey mantle, back, uppertail coverts, and upperwings. The belly is white and the underwings and under-tail that are ash-grey. It has a yellow-green bill and pink-grey feet.
Grey petrels are pelagic and typically stay between 32°S and 58°S during the non-breeding season. During the breeding season, they form colonies on several islands. Antipodes Island, with an estimate of 53,000 pairs, and Gough Island with 10,000 pairs are the biggest colonies, with others on Prince Edward Island, Marion Island, Tristan da Cunha, Crozet Islands, Kerguelen Islands, Amsterdam Island, Campbell Island, and Macquarie Island. They have an occurrence range of 68,800,000 km2 (26,563,829 sq mi).
They dive from heights of up to 10 m (33 ft) in pursuit of food, which is primarily cephalopods.
Grey petrels breed on Tristan da Cunha, Gough Island, the Prince Edward Islands, Crozet Islands, Kerguelen Islands, Macquarie Island and on New Zealand's Campbell and Antipodes Islands. They return to their breeding grounds in February and March and build a burrow for a nest. These burrows are on well-drained ground, often among Poa tussock grass, typically on steep terrain. By late March or early April, they lay their one egg, with both birds incubating it. After hatching, the chick is cared for by both parents until it fledges between late September and early December.
There is not a lot of recent information about this bird, but its population is believed to be shrinking slowly or possibly rapidly. Introduced predators such as cats, brown and black rats are contributing to the decline, as well as longline fishing, which is a major problem. This bird is the most commonly caught bycatch by longline fisheries in New Zealand waters, with one estimate at 45,000 birds in the last 20 years. Other predators are the weka and house mouse.
To assist in maintaining or increasing its population, it has been placed on CMS Appendix II, and ACAP Annex1. Gough Island has been designated as a World Heritage Site. Antipodes Island has had preliminary work done to start long term monitoring, and in 2007 the monitoring started. In 2001, brown rats were eradicated from Campbell Island, and in 2006, SEAFO tightened longline fishing regulations.
In the future, numerous tasks are planned, starting with a census on all the breeding locations. Also, studies on Gough Island pertaining to house mice, and finally, stricter fishing regulations enforced by FAO, RFMO, and ACAP.
