|Conservation status||Numbers probably stable. Vulnerable to introduction of predators (such as rats and cats) to nesting islands.|
|Habitat||Open sea. Favors warm ocean waters; off central California, fewer appear during years of colder water temperatures. Generally far offshore, but in southern California and Mexico, may occur regularly within a few miles of the mainland coast. Nests on rocky islands.|
Forages mostly by hovering or fluttering low over water and taking items from surface.
One. White, sometimes with small reddish-brown spots around larger end. Incubation probably by both sexes. Young: Probably fed by both parents.
Probably fed by both parents.
Includes crustaceans, small fish. Diet poorly known. May eat many small fish at times, and has been reported feeding on larval form of the spiny lobster. May also eat small squid. Scavenges floating fat from dead animals at sea.
Breeding behavior poorly known. Nests on islands, often in small colonies. Both members of pair may rest in nesting burrow for nearly 3 months before egg-laying. Active around colonies only at night. Adults give staccato calls while flying around colonies, changing to a musical trill when inside the nest. Nest: Site is in small opening among boulders, in crevice in cliff, or in burrow (especially abandoned burrow of Cassin's Auklet). Usually no nest built, sometimes a few bits of plant material.
Text © Kenn Kaufman, adapted from
Lives of North American Birds
Download Our Bird Guide App
After nesting, moves north regularly as far as central California. Common on Monterey Bay in late summer and fall during years of high water temperature. Most disappear after October, wintering south to waters off Panama and northwestern South America.
See a fully interactive migration map for over 450 bird species on the Bird Migration Explorer.Learn more
Songs and CallsA loud tuck-a-roo, given at nesting colonies.
Learn more about this sound collection.