Great cormorants, Hesse, Germany
© Wilfried Martin/Getty Image
Found in Europe, Asia, Australia, Africa and North America, great cormorants are experts at diving under the water's surface to catch bottom-dwelling fish. They sometimes even swallow pebbles to increase their weight, which enables deeper and longer dives. But these underwater fishing trips come at a price: Ironically for a water-diving bird, the great cormorant's plumage isn't sufficiently waterproof. As a result, cormorants must come ashore to dry themselves by spreading their wings open for long periods. This behaviour may also help with digestion or control their body temperature.