Description Audubon's shearwater

illustration chester a. reed

audubon s shearwaters on average 30 cm (12 in) in length—about half size of greater shearwater (puffinus gravis)—and weigh 170 g. there variation between populations, , normal size , weight range 30–33 cm (12–13 in) , 150–230 g (5.3–8.1 oz). wingspan 64–72 cm, tail around 8.5 cm long, exposed culmen measures 3 cm or less, , tarsus around 4 cm in length. in general appearance, small shearwater, black above , white below , hard distinguish relatives @ first glance.

the upperparts, rectrices , undertail coverts blackish-brown, @ least distal undersides of remiges, entire feathers. rest of underparts white, head below eye level. iris dark, feet dull pink black wash , black toenails, , bill grey, darker towards tip, , pinkish hue.

males , females alike. immature birds not have distinct plumage, while nestlings covered down feathers, grey above , whitish on belly.

it can confused manx shearwater (p. puffinus), has white undertail coverts , in direct comparison longer bill. other similar-looking species allopatric, though largely subantarctic little shearwater (p. assimilis) may range waters p. lherminieri found. has more white on face , underwing, smaller bill , greyish-blue feet.

its twittering calls , mewing heard @ night in breeding colonies.