The exotic and beautiful swallowtail is the UK's largest butterfly. A strong flier, residents can be spotted over wetlands in Norfolk during summer. Migrants occasionally appear in southern…

Lilac is an introduced species in the UK that can sometimes be found in hedgerows and along woodland edges. Flower spikes appear in spring, beautifully scented and packed with small, lilac-pink…

The serotine is one of the first bats to appear at night and can be seen around lamp posts chasing moths, or at treetop height. It likes to roost and hibernate in old buildings in the south of the…

The distinctive spiky, or 'bearded', green flower heads of wall barley appear from June to July and are easy to spot in an urban environment as they push their way up through pavements…

In spring and summer, look out for 'cuckoo-spit' - the frothy mass of bubbles that appears on plant stems everywhere. This is actually the protective covering for the nymphs of the tiny…

Flowering rush is a pretty rush-like plant of shallow wetland habitats, such as ponds, canals and ditches. Its cup-shaped, pink flowers appear in summer, brightening up the water's edge.

Mainly found in Southern and Eastern England, the Common hornbeam is a tall tree of ancient woodlands. Its large catkins appear in spring, and its winged seeds are dispersed by the wind in autumn…

A common thistle of roadside verges, rough grassland and waste ground, the Musk thistle has large, purple, nodding flower heads that appear in summer. It is attractive to a wide range of insects…

The streamlined black-throated diver is a superb swimmer and diver, but not so graceful on land! During the summer, the distinctive black patch on its throat appears, heralding the breeding season…

The common spotted-orchid is the easiest of all our orchids to see: sometimes, so many flowers appear together that they create a pale pink carpet in our woodlands, old quarries, dunes and marshes…

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…

Mackerel are a sign of summer's arrival, when they appear inshore in huge numbers all around the UK. As well as being a sustainable seafood choice, they are an important food source for many…