75: Double Crested Cormorant
I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. Before we start with today’s animal, I want to emphasize that biological classification as understood by western society has its roots in racism, sexism, and transphobia – here’s a good explainer about why.
Guess what bird is the only cormorant to nest in the interior west, including in rookeries on islands in Colorado lakes? Well, based on the title you probably DID guess that it is the Double-crested Cormorant (Nannopterum auritum), a bird whose habitat ranges from the Aleutian Islands all the way down to Mexico. The bird’s plumage is generally all black, except during the breeding season, when it acquires white plumes at the side of its head. Its face includes exposed orange skin and a distinctive turquoise eye. They are also one of the easiest birds to observe in the Denver area. In the spring, grab your binoculars and camera and visit Sloan’s Lake, Duck Lake in City Park, Kountze Lake in Lakewood, or other similar small lakes with treed islands through the city and even up into the mountains in Estes Park! You won’t be able to miss these large black birds as they socialize, roost, and dive for fish and crustaceans. Although cormorant populations dropped in the 1960s because of DDT, they have begun to rebound and are certainly abundant in the lakes I named above.
Some birds are more waterproof than others; for example, water really does roll off a duck’s back because of oily secretions that ducks and many other bird species preen into their feathers. Cormorants lack this feature for a good reason – double-crested cormorants can dive down to 25 feet below the surface of the water (and some other cormorant species can dive down to 150 feet!), so it helps to have heavy, waterlogged feathers rather than buoyant, waterproof ones. As a result, although they are strong swimmers, when they surface they often look like they are struggling as they flap their wet feathers and emerge from the water. They then have to perch on shore and spread their wings in order to dry out.