Why Is It Called A Double-crested Cormorant?

New birders and even some of us grizzled veterans are often left to scratch our heads over how certain birds got their names. Many species have handles that emphasize plumage characteristics that we rarely seen in the field. Unlike the museum curators who doled out these misnomers, we don't often see birds stuffed with cotton and lying flat on their backs. Some classic examples of misnamed birds include Red-bellied Woodpecker, Ring-necked Duck, and one of my favorites, the Red-cockaded Woodpecker. I have no idea what a "cockade" is and I'm not sure I want to ask.

It was crisp and sunny here in Eugene, Oregon today, a mega-rarity of late. So rather than spending most of the day staring into a computer screen, I headed out with my camera to fill some of the blank spots in my library of bird photos. I happened upon three species which have names that often puzzle beginning birders. One of these is the Double-crested Cormorant.

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These two Double-crested Cormorants, an adult (the closer bird) and a browner immature, present the profile we associate with this species. If you look closely you may see a few longer feathers poking up from the crown of the adult. These are part of the alternate (breeding) plumage that creates the lateral crests, which are not apparent from this angle. During most of the year, adults have a smooth crown profile much like that of the immature in this image.

Double-crested Cormorants spend most of their lives showing no crest whatsoever, let alone two of them. However, during late winter/early spring they undergo a partial head molt and acquire a set of specialized feathers that form bushy tufts or crests along each side of the crown (Hatch et al. 1999). In profile, these tufts generally go unnoticed, but if you see an adult Double-crested head-on this time of year, their crests can be quite conspicuous. Though both sexes acquire these specialized crown feathers, males typically have more than females. This appearance is short-lived. Most Double-crested Cormorants will shed their extra crown feathers by June (Hatch et al. 1999).

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Here is a head-on look at the same adult Double-crested Cormorant seen in the image above. Obviously the person who named this species got their first view of this species from a similar angle.

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I couldn't resist including this shot. You have to love the "comb over" look this Double-crested Cormorant is sporting.

David Irons took all of these photos on 4 April 2009 at Delta Ponds in Eugene, Oregon using a Canon EOS XSI 450D camera and a EF 100-400mm f/4.5-5.6 lens.

Literature Cited:

Hatch, Jeremy J. and D. V. Weseloh. 1999. Double-crested Cormorant (Phalacrocorax auritus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/441

Over the next couple days we will offer similar photo essays that will discuss how Ring-necked Duck and Violet-green Swallow got their names.

1

Serendipity. Yesterday a group of people enjoying the Saturday walk at Arcata Marsh and Wildlife Sanctuary on the far n. California coast were treated to nice looks at such a cormorant. From some angles, the bird truly looked “double-crested.”

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