Do seabirds drink seawater? © Getty Images

Do seabirds drink seawater? And if so, how do they prevent salt poisoning?

Excess salt can have fatal effects on the body, but seabirds have an ingenious way to combat these.

Asked by: Simon Harvey, via Twitter

All seabirds drink seawater – yet birds have less efficient kidneys than mammals, and so excess salt is even more toxic to them than to us. Seabirds cope with this by using specialised salt glands next to their eye sockets. These look like miniature kidneys and work in a similar way, pumping salt ions out of the bloodstream against the normal flow of osmosis. The extra-salty water drips down the side of their beak.

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