The linnet can be seen on farmland and heathland across the UK. But, like so many other farmland birds, linnets are declining rapidly, mainly due to agricultural intensification.

The Sessile oak is so-called because its acorns are not held on stalks like those of the familiar English oak. It can be found in woodlands mainly in the north and west of the UK.

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…

The coal tit is mainly found in coniferous woodland, but can also be spotted in gardens and parks. It is smaller than the great tit, but has a similar bicycle pump-like song.

The grey long-eared bat certainly lives up to its name - its ears are nearly as long as its body! It mainly forages over grassland and meadows, but is very rare in the UK.

As it names suggests, the common crossbill has a large bill that is crossed at the tip - perfect for picking the seeds out of pine cones. Look for it in conifer woodlands, mainly in the north and…

The adder's-tongue fern is so-named because the tall stalk that bears its spores is thought to resemble a snake's tongue. An indicator of ancient meadows, it can be found mainly in…