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.

A scarce but distinctive brown seaweed with curved, funnel-shaped fronds. It is a warmer water species at the northern edge of its range on the south coast of England.

The raven is famous for being the imposing, all-black bird that guards the Tower of London. Wild birds live in forests, and upland and coastal areas in the north and west of the UK.

Once widespread, this attractive plant has declined as a result of modern agricultural practices and is now only found in four sites in South East England.

The tiny firecrest vies with the goldcrest for the title of the UK's smallest bird. Once just a visitor, the firecrest can now be found breeding in woodlands in the south of England.

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.