As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

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.

The Canada goose is our most familiar goose, although it is not actually native to the UK. A common and bold bird, it can be found around most parks, lakes, reservoirs and gravel pits.

Cotoneaster was introduced to the UK in 1879 from Eastern Asia as an ornamental plant. It is now an invasive non-native species which is taking over valuable habitats including limestone…

The eerie, 'cur-lee' call of the curlew is a recognisable sound of wet grasslands, moorlands, farmland and coasts. Its long, downcurved bill is an unmistakeable feature and perfect for…

As its name suggests, giant hogweed it a large umbellifer with distinctively ridged, hollow stems. An introduced species, it is an invasive weed of riverbanks, where it prevents native species…

The common carp is a very large fish that is popular with anglers due to its size and fighting spirit. It frequents ponds, gravel pits and lakes, but is not native to the UK, being introduced in…

The Scots pine is the native pine of Scotland and once stood in huge forests. It suffered large declines, however, as it was felled for timber and fuel. Today, it is making a comeback - good news…

Yellow corydalis is a familiar 'weed' of gardens, walls and rocky places. It is a garden escapee in the UK, so is not a native plant. Try choosing natives for your garden to prevent…

The comma has distinctively ragged wing edges, which help to camouflage it - at rest, it looks just like a dead leaf! It prefers woodland edges, but can be spotted feeding on fallen fruit in…