These guys feed primarily on fish, and they can dive up to 100 ft. after their prey using their feet for propulsion. They can stay below water for 30-70 seconds. They will also eat crustaceans and amphibians. Unlike the anhinga that spears its prey, these guys grab prey in their bills.
Double-crested cormorants are monogamous and form large breeding colonies. The nests are large flat nests usually made from sticks and moss that is then covered with excreta. The nests are built anywhere from 10 to 40 ft up in the air in trees. Inland they will use cypress trees but coastal colonies typically use mangroves. both sexes incubate the nests for 28-30 days and the young remain with the nest for the next 21-28 days. Their numbers decreased substantially in the late 19th and early 20th centuries because of human persecution. However now this species is expanding their range and their numbers are increasing. Conflicts with humans arise because of this increase in numbers, and some people believe they are play a part in some fisheries collapses, but the evidence to support these claims are meager. Recently their has been proposed legislation to control their numbers because they will eat fish from fish farms.
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