The rare Adonis blue can be spotted on sunny chalk grasslands throughout summer. Males are a dazzling sky-blue in colour, while females are duller brown.

Often confused with the larger but similarly shaped lion’s mane jellyfish, the blue jellyfish can be colourless when young and develop a striking blue-purple bell as it matures.

Despite its name, the large blue is a fairly small butterfly, but the largest of our blues. It was declared extinct in 1979, but reintroduced in the 1980s and now survives in southern England.

A familiar garden bird, the blue tit can be seen around bird tables and feeders, as well as in woodlands and parks. Listen out for its trilling, 'tsee-tsee-tsee' song. It is smaller than…