Double-crested cormorant | |
---|---|
Adult in non-breeding plumage | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Suliformes |
Family: | Phalacrocoracidae |
Genus: | Phalacrocorax |
Species: | P. auritus |
Binomial name | |
Phalacrocorax auritus (Lesson, 1831) |
|
Synonyms | |
Carbo auritus Lesson, 1831 |
Carbo auritus Lesson, 1831
Dilophalieus auritus (Lesson, 1831)
Phalacrocorax dilophus
The double-crested cormorant (Phalacrocorax auritus) is a member of the cormorant family of seabirds. It occurs along inland waterways as well as in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico. Measuring 70–90 cm (28–35 in) in length, it is an all-black bird which gains a small double crest of black and white feathers in breeding season. It has a bare patch of orange-yellow facial skin. Five subspecies are recognized.
The double-crested cormorant is found near rivers and lakes and along the coastline. It mainly eats fish and hunts by swimming and diving. Its feathers, like those of all cormorants, are not waterproof and it must spend time drying them out after spending time in the water. Once threatened by the use of DDT, the numbers of this bird have increased markedly in recent years.
The double-crested cormorant was described by Rene Primevere Lesson in 1831. Its scientific name is derived from the Greek words φαλακρος (phalakros), "bald" and κοραξ (korax), "crow" or "raven", and the Latin auritus, "eared", referring to its nuptial crests. Its common name refers to the same nuptial crests.
Five subspecies are recognized:
The double-crested cormorant is a large waterbird with a stocky body, long neck, medium-sized tail, webbed feet, and a medium-sized hooked bill. It has a body length of between 70–90 cm (28–35 in) long, with a wingspan of between 114–123 cm (45–48 in). Double-crested cormorants weigh between 1.2–2.5 kg (2.6–5.5 lb). Males and females do not display sexual dimorphism.
This species has dark-colored plumage with bare super-loral skin and gular skin that is yellow or orange. An adult in breeding plumage will be mostly black with the back and coverts being a dark grayish towards the center. Nuptial crests, for which the species is named, are either white, black or a mix of the two. These are located just above the eyes with the bare skin on the face of a breeding adult being orange. A non-breeding adult will lack the crests and have more yellowish skin around the face. The bill of the adult is dark-colored. The double-crested cormorant is very similar in appearance to the larger great cormorant, which has a more restricted distribution in North America, mainly on the Canadian maritime provinces; it can, however, be separated by having more yellow on the throat and the bill.