_{^{A Double-crested Cormorant outstretches its wing to dry in the sun, a signature pose for the species, by The Lake in Central Park. Photo: Billy3001/CC}}

Don Riepe, Publications Committee | June 3, 2025 

With their striking silhouettes, Double-Crested Cormorants are a familiar sight along New York City's waterfront. There are approximately 40 species of cormorants in the world, and they are found on every continent except Antarctica. The Double-crested Cormorant is the most common of all the cormorant species and most widely distributed of the six species found in North America, ranging from Alaska to Mexico and throughout the lower 48 states. 

In 1980, I found the very first cormorant nest in lower New York Harbor, on Hoffman Island just south of the Verrazano Bridge. One nest, one chick. Today, there are hundreds of nests on Hoffman and nearby Swinburne Island, as well as many other islands in the harbor and in Jamaica Bay. The Double-crested Cormorant has become one of the most prolific colonial nesting birds in New York Harbor, sharing nesting grounds with Great and Snowy Egrets, Black- and Yellow-crowned Night Herons, Glossy Ibis, and Little Blue and Tricolored Herons, collectively known as the Harbor Herons. 

For over 40 years, NYC Bird Alliance has conducted annual Harbor Heron surveys, monitoring NY Harbor island colonies to count nests and young, and to assess habitat conditions. Cormorant nests are rather messy affairs built from large sticks and, in New York City, are often mixed with man-made materials such as netting, rope, and trash. Cormorants nest in large colonies, though their guano can kill the trees in which they nest, altering habitats that could otherwise be used by nesting wading birds.

Cormorants nest in big colonies and usually fledge three to four young each year. After leaving the nest, the young form juvenile bands, upwards of 30 birds clustered together. 

Unlike other waterbirds, cormorants lack the productive oil glands that keep feathers waterproof, making the birds less buoyant and more agile swimmers, which allows them to dive underwater to catch their food. The drawback of this adaptation is that they must dry their wings in the sun. You can easily spot Double-crested Cormorants with their signature outstretched wings sunning themselves on piers throughout the harbor.