audubons shearwater

Small size with comparatively short broad wings Blackish upperparts, white underparts with dark on breast sides white wing-linings, axillane and flanks, with broad dark margins to underwing. Flies with fairly fast wing-beats interspersed with short glides low over sea, although often rises in low arcs in strong winds.

Sometimes associates with other seabirds, occasionally follows fishing boats. Catches prey by plunge-diving followed by underwater pursuit, and by pattering across the surface with legs dangling. Offshore and pelagic waters.

Squid, fish. Diet not well known, apparently mostly small squid and fish. Has been reported to eat many sardines at times.

Audubon's shearwater (Puffinus lherminieri) is a common tropical seabird in the petrel family. Sometimes known as the dusky-backed shearwater the specific epithet honours the French naturalist Félix Louis L'Herminier. Certain populations are known variously as Baillon's shearwater tropical shearwater Bannerman's shearwater Mascarene shearwater and Persian shearwater some of these are considered distinct species by various authors. If they are all placed in P. lherminieri the North Atlantic little shearwater (otherwise often separated as P. baroli) is generally included here too. Thus these small shearwaters form a cryptic species complex. Audubon's shearwaters are on average 30 cm (12 in) in length&mdashabout half the size of the greater shearwater (Puffinus gravis)&mdashand weigh 170 g. There is some variation between populations and the normal size and weight range is 30&ndash33 cm (12&ndash13 in) and 150&ndash230 g (5.3&ndash8.1 oz). The wingspan is 64 to 72 centimetres (25 to 28 in) the tail is around 8.5 centimetres (3.3 in) long the exposed culmen measures 3 centimetres (1.2 in) or slightly less and the tarsus is around 4 centimetres (1.6 in) in length. In general appearance it is a small shearwater black above and white below and hard to distinguish from its relatives at first glance. The upperparts rectrices and undertail coverts are blackish-brown as are at least the distal undersides of the remiges but sometimes the entire feathers. The rest of the underparts are white as is the head below eye level. The iris is dark the feet are dull pink with a black wash and black toenails and the bill is grey darker towards the tip and with a pinkish hue. Males and females look alike. Immature birds do not have a distinct plumage while the nestlings are covered with down feathers grey above and whitish on the belly. It can be confused with the Manx shearwater (P. puffinus) which has white undertail coverts and in direct comparison a longer bill. Other similar-looking species are usually completely allopatric though the largely subantarctic little shearwater (P. assimilis) may occasionally range into waters where P. lherminieri is normally found. It has more white on the face and underwing a smaller bill and greyish-blue feet. Its twittering calls and mewing are often only heard at night in the breeding colonies.