Escaped or intentionally freed from fur farms in the 1960s, the American mink is now well established in the UK. Its carnivorous nature is a threat to our native water vole and seabird populations…

The graceful great crested grebe is a familiar sight on our lakes and reservoirs, and is well-known for its elaborate courtship dance, during which it rises vertically out of the water and shakes…

The vast, green mats that sometimes cover the surface of still water, such as ponds, flooded gravel pits and old canals, are actually Common duckweed. A tiny, single plant, it groups together to…

The gadwall is a dabbling duck, feeding at the surface of shallow water by 'upending' - putting its head down and its bottom up! Only a small number of gadwall nest in the UK, but large…

The humpback whale is making a comeback, with more and more individuals being seen in UK seas every year. They are well known for their acrobatic behaviour - so don't be surprised to see them…

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 small, shaggy-furred Brandt's bat roosts in all sorts of houses, old or modern. It is similar to the whiskered bat and they often roost together, but in separate colonies. It feeds low to…

The land caddis is the only caddisfly in the UK to spend its entire time on land, with no stage in water. Look in oak leaf litter over winter to see the grainy cases of the larvae, in which they…