Reindeer: The knees of many subspecies of reindeer are adapted to produce a clicking sound as they walk or run. The sounds originate in the tendons of the knees and may be audible from several hundred meters away.

Sei Whale: The name "sei" comes from the Norwegian "seje", used to describe a type of fish which gathers Norway's coast around the same time as sei whales.

Sumatran Rhinoceros: Sumatran rhinos like mud. Wallowing cools them and the mud prevents their skin from drying and cracking.

American White Pelican: Pelicans incubate eggs using their webbed feet, as they lack bare skin on their belly, known as a “brood patch”.

Smooth-Coated Otter: When swimming slowly, the otter uses all four of its paws to ‘doggy paddle’, but when swimming fast, it tucks its shorter front paws in, and uses its webbed hind feet and its tail for propulsion. It can close its ears and nostrils underwater.