A pretty and distinctive little waterbird, the mandarin duck was introduced from the Far East as its name suggests. Oddly for a duck, it nests in trees, sometimes high above the water.

Only a few pairs of snow bunting breed here, so look out for this striking black-and-white bird in winter around Scotland, the North West and the East coast of England.

The sweet chestnut is famous for its shiny brown fruits, or 'chestnuts', that are wrapped in a spiky, green casing and make a tasty winter treat. Look for this tree in woodlands in South…

Europe's largest frog is not naturally found in the UK, but was introduced to Kent and has spread throughout the southeast.

This common fungus puffs out clouds of spores when it's mature.

The sinuous otter is an excellent swimmer and can be seen hunting in wetlands, rivers and along the coast - try the west coast of Scotland, West Wales, the West Country or East Anglia for the best…