Er ei fod braidd yn swil, mae’r mamal morol rhyfeddol yma i’w weld yn agos at y lan mewn dyfroedd bas. Os byddwch chi’n llwyddo i fynd yn agos ato, cofiwch wrando am y sŵn ‘pwffian’ uchel mae’n ei…

The Sitka spruce was introduced into the UK from North America in the 19th century. It has been widely planted as a forestry tree; look for classic needle-like leaves and pale brown, domed cones…

Introduced from Japan in the 19th century, Japanese knotweed is now an invasive non-native plant of many riverbanks, waste grounds and roadside verges, where it prevents native species from…

These non-native limpets arrived from America in the 19th century and are now widespread in the UK. They form stacks and have a specially adapted shell which, when flipped upside down, looks like…

Our smallest breeding seabird, the storm petrel is barely larger than a house martin! They mostly nest among rocks or in burrows on small offshore islands.

Introduced into the UK in the 19th century, the diminutive little owl can now be seen along hedgerows, on farmland and in parkland across England and Wales. It often perches on a pole or rock,…

Have you ever seen those worm-like mounds on beaches? Those are a sign of lugworms! The worms themselves are very rarely seen except by fishermen who dig them up for bait.