Every year I look forward to the return of the Double-crested Cormorant on the river where I canoe. I find them a lot of fun to watch and who could resist those gorgeous blue eyes?! They can be a challenge to photograph if the lighting isn’t just right because they are all black so it’s easy to lose the details on the feathers but once in a while I get it right…
Cormorants diet consist mainly of fish so you’ll find them where there is good enough fishing to support their diet and they’re not particularly choosy about which fish they eat. They have an interesting fishing technique: they float low on the water and then dive and chase the fish underwater. The tip of a cormorant’s upper bill is shaped like a hook, which is helpful for catching prey. Their webbed feet help propel them through the water and they can dive anywhere from 4-24 feet underwater, holding their breath from 30-70 seconds at a time.
Comorants spend their time divided into eating or resting. They like to rest on an exposed spot such as a bare branch, log or rock and will spread its wings out. This behavior is thought to be a means of drying their feathers after fishing. Cormorants have less preen oil than other birds so they don’t shed water like ducks do and they can tend to get a bit water soaked. Although this might seem like a problem for a bird that has to dive for it’s dinner the wet feathers most likely make it easier for the cormorant to hunt underwater increasing it’s agility and speed.
Their population has fluctuated but as of right now they are rated an 8 out of 20 on the Continental Concern Score and they are not on the 2016 State of North America’s Birds Watch List. They’ve had a challenging history though: in the 1800 and early 1900s they were frequently shot and their numbers declined with westward settlement. They also suffered significantly from pesticide use which they ingested via the fish they ate which in turn caused their eggshells to thin. But with the ban on DDT in the 70s their population has grown and rebounded quite successfully.