Nudibranchs, also known as sea slugs, are much like their land-based relatives that you may spot in your garden. But, unlike your regular garden slug, the nudibranch can incorporate the stinging…

Largely confined to the north of the UK, the rare pine marten is nocturnal and very hard to spot. Reintroductions are helping it make a comeback.

The tiny, brown-and-white sand martin is a common summer visitor to the UK, nesting in colonies on rivers, lakes and flooded gravel pits. It returns to Africa in winter.

As its name suggests, the house martin can be spotted nesting in the eaves of houses in our towns and villages. Its intricate mud nests take days to build and are often returned to and used in…