Puffins are Scotland’s smallest and most distinctive breeding auk species. Returning onshore in the spring they nest underground in burrows before the pufflings' emerge in the summer. The adults bill appears large and colourful during the breeding season. The colourful outer part of the bill is then shed after the breeding season, revealing a smaller and duller true bill beneath.

After breeding, puffins winter at sea, usually far from coasts and often extending south of the breeding range and the new pufflings will return to land to breed once they mature after three or four years spent at sea.