Double-crested Cormorant (Phalacrocorax auritus)
Excited for the Vancouver International Bird Festival? The double-crested cormorant is one of the many amazing local bird species you will be able to learn about during the festival. Join one of our bird walks in Stanley Park to discover more about this unique diving bird!
Did You Know?
- Unlike the pelagic cormorant, the double-crested cormorant has a distinctive orange gular region (upper part of throat).
- Double-crested cormorant feathers lack waterproofing, decreasing the birds’ bouyancy to enhance diving.
- Their nests are made of bulky materials and will often include junk that they find on the coast such as rope and fishing nets!
Double-crested cormorants are large black waterbirds with a metallic gloss. They have a long hooked beak, bare orange skin around their face, and bright distinguishable turquoise eyes. Cormorants develop their black plumage in adulthood and therefore young cormorants are a lot browner than the adults.
Double-crested cormorants are widely distributed as they are the most widespread cormorant in North America. They are found in many types of aquatic habitats including ponds, lakes, rivers, lagoons and coastal areas. They breed mainly along the coasts, the Great Lakes and other inland bodies of water.
The Double-crested cormorant’s diet consists mainly of fish but they also eat other aquatic animals, insects, and amphibians. Their diet varies with seasonality and place and therefore can include crabs, fish, frogs, eels, mollusks and plants depending on where they are situated.
Double-crested cormorants can nest in colonies in trees, on the ground, or on cliffs. Both parents incubate the pale blue-green eggs for a one-month duration. Typically the clutch size of these cormorants is three to five. The chicks fledge (develop grown feathers) after 35-40 days and are then ready for flight.
In the 1900s, the population of double-crested cormorants was reduced by hunting and pesticide use. However, the population regained its numbers in the 1970s (some areas even saw an explosion of birds). Double-crested cormorants can be a nuisance to fish farmers and in some areas they have been blamed for the collapse of fisheries.