Cormorants on Our Coast

As the Jersey shore's winter bird residents return to our waterways for the season, you'll start seeing a lot more of one distinctive-looking avian: the double-crested cormorant.

What it is: The double-crested cormorant is a large black diving seabird with a long neck and a slightly hooked beak. The beak and lores – the area around the bird's eyes – are yellow to orange. It can grow to about 35 inches long, with a wingspan of up to 4 feet. 

Cormorants are unusual among water birds in that their wings aren’t fully waterproof. Ornithologists used to think this was because they didn’t produce enough of the oil that typically repels the water from most birds’ feathers. As it turns out, it has more to do with structure. Cormorants’ feathers are specialized to allow them to become waterlogged, so that the birds can dive deeper and more easily.

The flip side is that those wet wings have to be dried. That’s why you’ll often see cormorants perched with their wings spread. This wing-drying or sunbathing posture is also employed by other species who use to regulate body temperature, but cormorants appear to only need to use it to dry out their plumage.

Double-crested cormorants gather in large groups to nest on north Atlantic and Pacific coasts and in the U.S. interior. They tend to hang together wherever they overwinter, too, and you’ll likely see them in groups as they fish and dry their wings.

Where to find them: Once threatened because of the pesticide DDT, cormorants have made a major comeback, and are now a common sight along North America’s coasts and interior waterways.

Look for them on any big, open body of water, especially the tidal areas of rivers and at inlets. They’re easy to spot when perching with wings spread, and almost as recognizable when swimming; they sit low in the water, with the head held at an upward angle.

Why bother: Cormorants are another bird conservation success story. The species has rebounded from the devastating effects of DDT in the middle of the last century to become widespread once again – so much so that they’ve become controversial, due to their appetite for some commercial harvested fish.

Not all scientists agree that cormorants are a significant factor in the decline of some fisheries, but there’s enough concern over their growing numbers that the U.S. Fish and Wildlife Service has begun to allow culling of some populations.

Their population swings aside, cormorants are an interesting subject for birdwatchers due to their unusual wing-drying behavior and dramatic dives.