The cormorant (Phalacrocoracidae) is a family of predominantly black birds with hooked, laterally compressed bills, naked, coloured skin on the throat and noticeably stiff tail feathers. Highly adapted to an aquatic environment (eg, all toes are connected by a web), cormorants are awkward on land. When standing or perching they assume an upright posture.
Thirty-seven species occur worldwide; 4 in Canada, 3 restricted to marine environments. The great cormorant (Phalacrocorax carbo, 2.4-5.3 kg) breeds along the Gulf of St Lawrence and the East Coast. Brandt's cormorant (P. penicillatusabout 2.1 kg) inhabits brackish to nearshore waters around Vancouver Island. The pelagic cormorant (P. pelagicus, 1.6-2.7 kg), Canada's smallest, most marine species, nests on cliffs along the BC coast, often wintering on the open ocean. The double-crested cormorant (P. auritus 1.7-3.5 kg) occurs across much of southern Canada, inhabiting freshwater lakes, brackish waters and marine islands.
Nests are on the ground or in trees, on islands or cliffs. Cormorants are susceptible to disturbance when nesting.
Cormorants are fish eaters. They forage gregariously and capture prey by diving from the surface. Frequently, swimming birds form a semicircle, driving their prey. Capable of diving up to 37 m, cormorants perhaps use wings as well as feet for underwater propulsion. Cormorants have been persecuted for depletion of economic fish stocks, although they subsist mainly on coarse fish.
Double-crested cormorant populations, greatly affected by habitat loss caused in part by the drought of the 1930s and by pesticides, have increased significantly in recent years, and their populations are now controlled in parts of their range in eastern Canada.