Great Black Cormorant

Great Black Cormorant D8881

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Great cormorant (Phalacrocorax carbo), known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, the large cormorant in India and the black shag further south in New Zealand, is a widespread member of the cormorant family of seabirds. The great cormorant is a large black bird, but there is a wide variation in size in the species wide range. They are tied as the second largest extant species of cormorant after the flightless cormorant. Great cormorants are mostly silent, but they make various guttural noises at their breeding colonies. This is a very common and widespread bird species. It feeds on the sea, in estuaries, and on freshwater lakes and rivers. The great cormorant often nests in colonies near wetlands, rivers, and sheltered inshore waters. Pairs will use the same nest site to breed year after year. It builds its nest, which is made from sticks, in trees, on the ledges of cliffs, and on the ground on rocky islands that are free of predators. The great cormorant feeds on fish caught through diving. This bird feeds primarily on wrasses, but it also takes sand smelt and common soles. The average weight of fish taken by great cormorants increased with decreasing air and water temperature. Cormorants consume all fish of appropriate size that they are able to catch in summer and noticeably select for larger, mostly torpedo-shaped fish in winter. Thus, the winter elevation of foraging efficiency described for cormorants by various researchers is due to capturing larger fish not due to capturing more fish. Many fishermen see in the great cormorant a competitor for fish. Because of this, it was hunted nearly to extinction in the past but nowadays with increasing populations have once again brought the cormorant into conflict with fisheries.