Double-crested Cormorant

Photos by Stan Tekiela

by Stan Tekiela
© NatureSmart

September 30, 2024

We people love to assign blame or shame no matter the situation. For some crazy reason this translates over to our view of nature. There are a number of species that people don’t seem to like at all, based on nothing other than our desire to assign blame. The Double-crested Cormorant (Nannopterum auritum) is a classic example of a species of bird that people don’t like and have piled on a heap of blame upon.

These birds have been vilified and persecuted by people going back hundreds of years. For example, Elizabeth the First, the Queen of England, in the late 1500’s declared this bird to be a pest and put out a bounty on cormorants. She said they were pests and needed to be eliminated.

To add to this, many books, movies, and poems all depict the cormorant as a bad bird and many associated it with the devil. With this kind of bad press, you can see why this bird is hated even by those who don’t know anything about it. So, let’s learn a few things about the cormorant.

There are many different species of cormorant, approximately 40 in the world. The most common in North America is the Double-crested Cormorant so let’s learn about this one. The Double-crested Cormorant is a large, all black waterbird, with large, webbed feet and an impressively large, hooked bill. They are only about 2-5 pounds. They have a yellow patch of skin under their lower bill, called gular skin. They have sparkling blue eyes and lining of their mouth, which isn’t very common in birds.

The common name “Double-crested” refers to special feathers on either side of their head that can stand up and away from the head, so it looks like they have two crests. They don’t display these crests very often, so most people never see it, which also contributes to the misunderstanding of this bird.

They have relatively short wings, but they are still very strong flyers. Their bill is long and thin and a strong down-curving tip, call the nail. They use their bill to catch fish underwater. They use their large, webbed feet to propel them through the water, leaving their wings folded at their sides. So they don’t “fly” through the water. They are true swimmers.

After spending time under water, the cormorant often sits out in the sun to dry out. Cormorant feathers, more specifically the contour feathers that cover the bird’s body, are different from other birds. At the base of the feather the structure is tight and repels water, but the outer part of the feather is open and absorbs water, rather than shedding it, like other bird’s feathers. So, part of the feather gets waterlogged. This helps the bird stay underwater with less effort, allows it to be more agile and increases maneuverability. After all they need to overtake fish underwater to catch something to eat.

In the past it was assumed that the cormorants didn’t have the oil producing gland near the base of their tail, called the preening gland. The oil excreted from the gland was believed to give birds their waterproofness. Now we know that it is the feather structure that makes a bird waterproof. Recent studies show that cormorants do have the preening gland and it’s fully functional. So once again we were wrong after making assumptions when we see bird behaviors.

More recent studies show that birds who are “sunny” themselves, might be doing more than just drying feathers. There is some evidence that the birds are using the sun to raise their body temperatures and thus increase their digestion rate. Others suggest that the increased UV light from the sun helps them break down and digest their food. Whatever the reason, I am hoping we have learned that making quick assumptions or playing the quick blame game is often proved to be wrong. Until next time…

Stan Tekiela is an author / naturalist and wildlife photographer who travels extensively to study and capture images of wildlife. He can be followed at www.instagram.com and www.facebook.com. He can be contacted via his website at www.naturesmart.com.