What Does a Double-crested Cormorant Look Like?
This black waterbird isn’t quite as big as a Canada goose, but is much larger than a crow. The body stretches about 27 to 24 inches, with a long sturdy neck. Their wings span up to 4 feet.
Mature adults have fully black bodies, while juveniles have paler feathers on their head and breast. In breeding season, adults have bright orange patches around their dark hooked bill, while juveniles and non-breeders have lighter orange skin and a more yellow bill. Males and females look alike at both ages.
“This is a great bird to look for if you are just getting into bird-watching,” says Erika Zambello of Audubon Florida. “They are large, easy to see and identify, and live across the United States at different times of the year. If you’re near large water bodies, look for cormorants!”
Anhinga vs. Cormorant
Both anhingas and double-crested cormorants are dark birds that specialize in eating fish,” says Erika. “However, with a closer look they are relatively easy to tell apart. Anhingas swim beneath the surface of the water, with only their heads exposed. By contrast, cormorants swim with their bodies above the surface.”
She continues: “On land, it’s important to look for overall bill and body shape. Cormorants have hooked bills, while anhingas have long, pointed bills and a longer tail.”
Anhingas are almost never found far inland away from the coasts, so if you’re in the middle of the country, your bird is almost certainly a cormorant.
Range and Habitat
Cormorants are aquatic, often found around big bodies of water like large lakes or the ocean. They also need plenty of perching space, so look for them in trees or on exposed rocks in the sun. This water bird is present year-round in Florida and other coastal areas around the country, and spends its winters in the south, especially along the Gulf Coast.
During the summer breeding season, this fish-eater expands its range throughout the whole country and up into Canada. You’ll find them just about anywhere there’s a river or lake big enough to support their fish-heavy diet.
Nesting Habits and Eggs
These are gregarious birds, often assembling in large flocks, and their nesting behavior reflects that. Many birds gather together in a nest colony (sometimes up to 4,000 strong), usually on top of trees or rocks over water.
Males choose a nest site, then advertise for a mate by standing with their heads and tails pointed directly up, displaying small tufts of feathers on each side of their head. They wave their wings to attract attention, and when a female arrives, open their bill to flaunt the bright blue skin inside their mouth.
Pairs build their nest together from small sticks, and line it with grass. A clutch can contain one to seven eggs, pale blue and up to 3 inches long. The eggs take up to a month to hatch, after which the parents work together to feed them until they leave the nest.
Fledglings take their first flight at around five to six weeks, and set out on their own by about 10 weeks old. They often return to the same nesting colonies a few years later to find mates of their own.
Learn about great egrets nests and courtship.
Double-Crested Cormorant Diet
“Studies have shown that this species of cormorant eats more than 250 species of fish,” Erika says. They also occasionally eat crustaceans and amphibians. Cormorants dive for their dinner, pushing themselves along with powerful webbed feet.
They bring their catch to the surface, then flip it into the air and catch it again, positioned so that it will slip easily down their throat. Their throats expand to accept surprisingly large prey, and watching the meal slide down can be a real show.
Unlike other water birds, cormorants don’t have as many preen oils on their feathers, allowing them to dive deep and navigate smoothly underwater. “People will often see cormorants standing with their wings outstretched,” says Erika. “They need to do this in order for their wings to dry in between fishing trips.”
Sounds and Calls
Bird sounds courtesy of the Cornell Lab of Ornithology
These are not melodious birds, and you’re most likely to hear their grunts and squawks as they take off or land. A colony together can be louder, as they gargle and croak in large numbers.
Double-Crested Cormorant Controversy
Large flocks of these birds also descend on commercial fisheries from time to time, as well as local lakes and ponds stocked for anglers. This, plus their habit of nesting in huge numbers, have given them a bit of a bad reputation. Their droppings are extremely acidic, causing damage to trees and eventually killing them off entirely. Some consider them serious pests.
Erika feels this is unfair in many cases. “Cormorants are sometimes considered a nuisance because they are noisy and their scat, like most wildlife, can smell. They can form large nesting colonies in residential areas, and heavy nests can damage vegetation,” she acknowledges.
“But it is important to remember that these birds are just doing what they know best, and it is up to us to ensure that we can strike a balance between human and wildlife needs. This is their home too, and we can all live successfully and safely together.”
About the Expert
Erika Zambello is the communications director for Audubon Florida. A former National Geographic Young Explorer, she has a master’s degree in environmental management, ecosystem science and conservation from Duke University.
Sources
- All About Birds – double-crested cormorant
- National Audubon Society – double-crested cormorant
- https://www.aphis.usda.gov/sites/default/files/Cormorants-WDM-Technical-Series.pdf
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