Brandt's Cormorant

Three species of cormorant are normally present in Sonoma County--Double-crested Cormorant (Phalacrocorax auritus), Brandt's Cormorant, and Pelagic Cormorant. Brandt's and Pelagic Cormorant are exclusively coastal species. Brandt’s Cormorants may be encountered well out at sea but are very rarely seen even a short distance inland. Double-crested Cormorant is common at the coast but just as likely to be found somewhat inland or perched in a tree. Locally, the three species can be found together fairly reliably at the mouth of the Russian River. Brandt’s Cormorant is present in Sonoma County all year. Easily seen off Bodega Head on rocks or flying offshore there and in other coastal areas, usually low to the water and often in linear formations. Nests on offshore rocks, often near Pelagic Cormorants, but the Brandt’s Cormorants nest in loose groups, favoring flattish or gently sloping rocks, while Pelagic Cormorants pair off and favor much steeper, craggier areas.

A large, chunky, dark cormorant with a heavy bill obviously hooked at the tip. Overall, blackish grey in non-breeding plumage but with a grey patch of skin under the chin that turns blue during the breeding season and, below that, a more conspicuous buff patch at the throat--although both the patch and the bare skin can be hard to see in the field. Young birds are browner than adults and have a somewhat pale breast and may show a less-defined chin patch.

Often confused with its close relative Pelagic Cormorant (Phalacrocorax pelagicus), which, however, is distinguished by its smaller, rounder head and very thin, pencil-like bill with a dainty hook that is obvious only at close range and when the bird has its bill open. Double-crested Cormorant is usually less confusing for a number of reasons. As noted above, it may stray inland and perch in trees (virtually eliminating the other two species), and it flies with a characteristic kink in the neck lacking in both Brandt's and Pelagic Cormorants, which fly with their necks held relatively straight. Double-crested Cormorant has a conspicuous orange-yellow patch at the throat in all plumages (although much brighter during breeding season). The yellow extends to the lores and may extend along the lower mandible. Brandt's Cormorant has a pale beige to white throat patch that acquires a blue segment in breeding plumage (photo below). Pelagic Cormorant, is the smallest and most slender of the three species and has a notably thin bill without the bulge and conspicuous hook at the tip shared by Double-crested Cormorant and Brandt's Cormorant. The entire head of Pelagic Cormorant looks small when seen beside Brandt's. Pelagic Cormorant develops white patches at the lower flanks in breeding plumage (photo below) that make it very easy to spot and distinguish during breeding season, especially in flight. Brandt’s Cormorant lacks these patches. In breeding plumage, Pelagic Cormorant will have red at the base of the bill, but, again, but can be hard to see in the field. The 2010 Peterson edition has a good comparison of the heads of the three species on page 81.

Swimming cormorants are often confused with loons at a distance because they swim similarly low in the water and typically with their heads held up, which may suggest Red-throated Loon (Gavia stellata) in particular.