A stocky, little sandpiper, the knot can be spotted in estuaries from August onwards, migrating here from the Arctic where it breeds. Look out for it probing the muddy sand with its specialised…

The muntjac deer was introduced into the UK from China in the 20th century. It has gained a stronghold in southeast England, where it can cause damage to our woods through browsing.

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…

A summer visitor, the wheatear is a handsome chat, with black cheeks, white eyestripes, a blue back and a pale orange chest. Look for it on upland heaths and moors.

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…

Dittander is a herb of coastal saltmarshes and damp ground. Its waxy leaves and long roots help it to survive in this harsh environment. Due to its peppery taste, it has also become a popular…

Like many of our farmland birds, the yellowhammer has declined in number in recent years. Spot this bright yellow bird singing from the top of a bush or fence, or in a mixed-species flock in…