In May, our hedgerows and woodland edges burst into life as Midland hawthorn erupts with masses of pinky-white blossom. During the autumn, red fruits known as 'haws' appear.

Look for the wood warbler singing from the canopy of oak woodlands in the north and west of the UK. Green above, it has a distinctive, bright yellow throat and eyestripe.

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.

The lesser-black backed gull can be spotted around the coast in summer, with the biggest colony on Walney Island, Cumbria. Look for it over fields, landfill sites and reservoirs during winter.

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…