The Procellaria petrels represent a group of large and bulky seabirds that can be placed between the shearwaters of the genus Calonectris and the more fulmarine petrels. Until recently the largest of the Procellaria-species, the White-chinned and the only slightly smaller Spectacled Petrel, were considered to be conspecific. Now they are split into two separate species. Both have a large and strong bills, ivory colored with black sulci between the horny plates and ivory colored ungues, the latter sometimes slightly darker in the Spectacled Petrel. The Westland and Parkinson?s Petrel are also two similar species, of which the latter is a smaller version of the first. Both have ivory colored bills (with a bluish tinge in young birds), with blackish ungues. In the Parkinson’s the black is less extensive than in the Westland. There is no overlap in bill measurements. The Westland Petrel is of the same size as the White-chinned and its culmen is always longer than 47.8 mm. That of the Parkinson?s Petrel not longer than 45.1 mm The bill of the somewhat distinct Grey Petrel is about the size of the larger Procellarias, with the same pattern as the White-chinned and pectacled, but instead of ivory, more pearl-grey. The Grey Petrel’s somewhat lighter bill structure comes close to that of the Calonectris species. Because its somewhat different coloration, habits and structure this species formerly formed a genus of its own: Adamastor. It is now considered to belong to Procellaria.
Listen to the sound of White-chinned Petrel
Copyright remark: Most sounds derived from xeno-canto
recorded by Andrew Spencer
Video White-chinned Petrel
copyright: Brooke Clibbon
P. aequinoctialis constitute the majority of bird bycatch in Southern Ocean longline fisheries. It is one of the commonest species attending longline vessels off south-east Brazil during winter and constitutes virtually all the recorded seabird bycatch from the Namibian hake fishery. In South Africa, White-chinned Petrels constitute 10% and 55% of the bycatch in pelagic and demersal longline fisheries. Prior to the introduction of bird streamer lines as a vessel permit condition in August 2006, approximately, 10% of the 18,000 birds killed annually in the South African hake trawl fishery were White-chinned Petrels. In the Indian Ocean, between 2001 and 2003 the legal longline fishery for Patagonian toothfish Dissostichus eleginoides killed 12,400 P. aequinoctialis per year.