Though not exactly singers, double-crested cormorants do grunt and caw. In the warmer months, they can often be seen swimming and diving from the surface of the water for fish. They breed in colonies on Swinburne and South Brother Islands in June and July, sporting the breeding plumage -- double "crests" above their eyes -- for which they are named.

Above: A double-crested cormorant drying his feathers.