Soft-plumaged petrel

Voice

Silent at sea, and a European observer should not expect to hear it at all. At the breeding islands, birds calling in flight over the slopes after dark give a medium-pitched, musical moan, oo-eer, repeated with a rising and falling pitch, broken by thin shrill squeaks; from inside the burrow there is little more than a soft grunting.

Identification

A medium-small petrel, about 35 cm long, grey above with a darker M across the open wings, white below, and with wings that look narrow and slightly angled at the carpal. The face is white with a solid blackish patch through and around the eye, so the bird looks masked, and the crown and hindneck are grey. The single most useful mark is the chest: a grey band, usually complete or nearly so, runs right across the white underparts. The underwing is uniformly dark grey-brown, with no pale flash at all. The bill is short, deep and black. In wind it flies in high, bounding arcs, rising well above the horizon on stiff wings and dropping back into the troughs. A wholly dark morph occurs in part of the range and shows the same shape and the same dark underwing, but no white at all.

Confusion species

This is where the page has to be honest. Fea's Petrel, the bird a European observer is far more likely to be looking at, lacks the complete chest band — grey is restricted to a patch at each side of the breast — and shows a pale grey rump and tail that contrast with a darker mantle and wing; it also has a noticeably deeper bill and broader-based wings. Zino's Petrel differs from Fea's only in being smaller and finer, above all in bill depth, and cannot be separated from it in the field at all, so any of these three birds that will not show its chest and tail properly is best left as a Fea's/Zino's-type petrel. The dark underwing is shared by all of them and settles nothing. Great Shearwater is bigger and browner, with a dark cap cut off by a white collar, a white band above the tail and a white underwing. Cory's and Scopoli's Shearwaters are much larger and slower, with a heavy yellow bill and a white underwing. Old European records of Soft-plumaged Petrel from before the 1990s were reviewed once the Fea's and Zino's problem became clear, and most of them are now carried as unidentified petrels of the Fea's group.

Habitat

Strictly a bird of the open ocean over deep water, feeding far from any coast. It takes squid, small fish and crustaceans from the surface, mostly at night, snatching them in a banking, low pass without settling for long, and it gathers where fronts and upwellings concentrate prey. It comes to land only to breed, on southern islands, and even there only after dark.

Range and movements

The breeding range lies in the southern hemisphere: Tristan da Cunha and Gough, the Prince Edward and Crozet groups, Kerguelen, the Antipodes, Macquarie and a small colony in the Maatsuyker group off Tasmania. Outside the breeding season birds spread over the southern oceans and north to Brazil, southern Africa and Australia. In the area covered by this guide it is no more than a vagrant, with a handful of records from northern Europe and from the Red Sea approaches, and no pattern that an observer can plan around.

Where and when to look

There is no cape and no month that will produce this bird to order. The realistic approach is to take the long pelagics that already run for gadfly petrels — the multi-day trips out of Madeira and the Azores in late summer — photograph every Pterodroma that passes, and then examine the pictures for a chest band that closes across the breast and for a tail that does not stand out paler than the back. If you simply want to watch the species, the crossings between Cape Town and Tristan da Cunha put it alongside the ship for days on end.

Conservation status

Not globally threatened (IUCN: Least Concern). The world population runs into hundreds of thousands of pairs and the species holds several large island colonies. Introduced house mice on Gough Island kill chicks in the burrows and are the most serious single problem; rats and cats have reduced numbers on other islands, and burrow-nesting birds everywhere remain vulnerable to any new predator reaching an island. For the waters of this guide the species carries no conservation role.