Mae'r rhywogaeth yma o siarc main a chain i'w gweld yn aml yn agos at y lan o amgylch ein harfordiroedd a gall dyfu i fod hyd at 6 troedfedd o hyd.

The wigeon is a colourful duck that can often be spotted wheeling round our winter skies in large flocks. A dabbling duck, it surface-feeds on plants and seeds in shallow waters.

Tansy is an aromatic plant of rough grassland, riverbanks and verges that has button-like, yellow flower heads. It is the main foodplant of the rare Tansy Beetle, now found at only two places in…

A non-native species originating from Asia, the harlequin ladybird is prevalent in towns and gardens.

This purply-brown seaweed is a common feature on our rocky shores and on our dinner plates.

Sika deer were introduced to the UK in the 19th century. They are native to eastern Asia.

Look out for the swallow performing great aerial feats as it catches its insect-prey on the wing. You may also see it perching on a wire, or roosting in a reedbed, as it makes its way back to…