Puffins also known as the clowns of the sea are the best known of the British auks which also include the guillemot, razorbill and various auks.
Puffins are short, stocky black and white sea birds with small but powerful wings which they use to their advantage above and beneath the waves to catch fish with.
The large beak for which they are so well known, is only colourful during the summer months when it's used to attract a mate with.
Any food caught is held between the tongue and upper mandible, enabling them to hold many sand eels and small fish at once and continue fishing.
Though only a very few puffins breed on the British mainland, there are many colonies on offshore Islands.
In Wales they can be seen off the coast of Pembrokeshire, on the Islands of Skomer where there are approximately 6,000 pairs and Skokholm, which is home to around 2,000 pairs.
The best time to see puffins in Wales is from around April onwards when the puffins return to claim their burrows, fighting with each other and manx shearwater which also nest underground.
But they don't arrive in significant numbers until June-July. By August, however the birds are already beginning to leave so don't leave it too long if you're planning an island visit.
As well as puffins, over 200,000 Manx shearwater nest on Skomer and have a similar black and white makeup, although with the latter being nocturnal they are rarely seen in daylight hours.
Puffins form long-term pair bonds with the female laying a single egg and both parents taking turns to incubate the egg and feed the chick which emerge as a large, ugly ball of black fluff - in stark contrast to their parents.
Once the chicks have fledged they will remain out at sea for up to two years before returning to land, to find a mate and breed.
Research on Skokholm and Skomer's puffins has been carried out for many years and the first studies were carried out by Ronald Lockley back in the 1930s on Skokholm.
Nowadays Skomer Island has a dedicated warden and you can even stay overnight on the island or volunteer if you wish to stay longer.
You can keep up to date with island life via the Skomer Island blog.
Try one of the walks from Derek's latest walking series on BBC One Wales.
Find out about the wildlife you can find on your doorstep.