Pelagic cormorant

The pelagic cormorant (Urile pelagicus), also known as Baird's cormorant or violet-green cormorant, is a small member of the cormorant family Phalacrocoracidae. Analogous to other smallish cormorants, it is also called the pelagic shag occasionally. This seabird lives along the coasts of the northern Pacific; during winter it can also be found in the open ocean. Pelagic cormorants have relatively short wings due to their need for economical movement underwater, and consequently have the highest flight costs of any bird.

It was formerly classified in the genus Phalacrocorax, but a 2014 study supported reclassifying it and several other Pacific cormorant species into the genus Urile. The IOC followed this classification in 2021.

This is a smallish cormorant which measures 25 to 35 in (64 to 89 cm) in length, with a wingspan of about 3.3 ft (1.0 m) and a weight of 52–86 oz (1,500–2,400 g) when fully grown. Adults in nonbreeding plumage are all-black with a metallic iridescence. In breeding plumage they grow two short crests (one on top of the head and one at the nape), white thighs, and scattered white filoplumes on the head and neck. The long thin bill and the large feet with all-webbed toes are black throughout the year, while the patch of dark naked skin below the eye turns a vivid magenta in the breeding season.

Males and females do not differ in appearance, though the latter is a bit smaller. Immature birds lack iridescence and are dark brown, grading into slightly lighter brown on the underside.

The widely sympatric red-faced cormorant (U. urile) looks very similar. Breeding adults are easily told apart by the amount of naked facial skin, which does not noticeably extend beyond the eye in U. pelagicus, but extends to above the bill and above and behind the eye in U. urile; the latter species also has larger crests. Juveniles and nonbreeding adults of the two species are often indistinguishable even to trained observers when in mixed flocks, or if they cannot be observed up close. In the former case, the large naked face "mask" and light bill of U. urile can be easily recognized, in the latter case its larger size (though male pelagic cormorants can be as large as female red-faced cormorants). Unlike the red-faced cormorant, the present species usually calls out before taking off, particularly during the breeding season. In courtship display, nest material is typically torn and moved about (which U. urile might not do) and the males apparently do not bow their heads before the females as U. urile males do. Other North Pacific cormorants and shags are larger, with a thicker bill, and/or lack the white thighs in breeding plumage.