If any wild animal is universally adored, it has to be the penguin. People seem to love their portly, torpedo-shaped bodies, striking black and white plumage, and their unintentionally hilarious waddling when on land. However, the penguin is uniquely designed for a life lived largely at sea. Since a penguin's diet consists primarily of seafood caught while swimming, it is inevitable that the birds will ingest seawater. To handle this, many marine birds have a gland near their eyes that efficiently filters out salt from the bloodstream. The salt is then excreted from the bird's body through the bill, making the bird appear to have a runny nose. Penguins frequently shake their heads to get the salt off their beaks, or they sneeze out the excess.
In general, however, penguins don't drink seawater to hydrate themselves. They usually drink from fresh water sources such as pools and snowmelt, or they eat fresh snow, in order to get an adequate amount of water. Penguins in captivity are usually kept in fresh water, and this doesn't seem to bother them. In fact, they seem to prefer fresh water when given the choice of where to swim.
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