Mudwr sy’n teithio'n dda ac mae'r fantell dramor yn cyrraedd yma bob haf o Ewrop ac Affrica. Mae'r glöyn byw oren a du hardd yma’n ymweld â gerddi yn rheolaidd.

Known in America as the 'Eared Grebe' because of its golden ear tufts, the black-necked grebe is a rare nesting bird in the UK. It is easiest to spot around southern coasts in winter.…

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…

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…