Every year in late April to early May, seabirds known as double-crested cormorants (Phalacrocorax auritis) make their homes on and near Alberta lakes and rivers to breed and raise their young. So named because of the long, fine feathers that appear behind each eye in spring, they are one of approximately forty sub-species in the world.
The name cormorant is a contraction of two Latin words; corvus and marinus which when put together mean “sea raven”. With their penchant for fishing and their black colour it is easy to see why.
The double-crested cormorant is a large black bird with a long sinuous neck and a yellow-orange throat patch. They weigh between 1.2 and 2.5 kilos and are exceptional divers, some able to dive to depths of 45 meters using their powerful webbed feet and using their wings as rudders. Cormorants eat a wide variety of fish along with some crustaceans, amphibians and insects. Their long beak, with the tip of the bill shaped like a hook, is an excellent aid in catching prey.
A cormorant’s time is spent almost equally between fishing and resting. Some people believe that their oil glands are insufficient for waterproofing, and although these oil glands may help them be a better diver, it also means they must spend a large portion of time drying their wings. Observers will often find cormorants on top of tall trees of telephone poles with their wings outstretched to catch the drying rays of the sun.
Cormorants are colonial nesters whose guano has been known to kill the very trees they perch upon. At the very least, it will stain and discolour any rocks below. Cormorants are also known to create pellets of undigested bones and fish scales which they expel much the same as some species of owls.
If spring ever comes, we can expect to see double-crested cormorants soon after!
By Linda J. Schlegel, AIWC Volunteer
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