Puffins

Puffin at Oiseval St.Kilda

The Arctic Puffin (Fratercula arctica) is a member of the Alcidae or Auk family. In Gaellic they are called Buthaid. Apart from their unmistakable colourfull bill, their bright orange feet are equally striking. They are really amusing to look at. They are not real good flyers, and they have difficulties to fly off from the surface of the water as well as to land.

On St. Kilda the colony of Puffins is the largest breeding concentration of Puffins in Britain. The majority breeds on Boreray and Soay, but on Dún are also large numbers, and Dún is more accessible for investigation. Puffins breed on the slopes in burrows they dig out themselves. They usually lay only one egg. After about 40 days from hatching, the pufflins fledge. The parents don't abandon  the chicks, but they are feeding them less food. Especially in darker and mistier nights, these young pufflins are attracted to the sounds and the lights in the street on Hirtha.
Since 1973 until 1996 these stranded young Puffins were collected, counted, ringed and weighted in order to studie the breeding success and fledging conditions of Puffins (Harris, Murray & Wanless, Bird Study, 1998).

The results show a decline in breeding success and condition of the young Puffins in the period between 1973 - 1998. Successfull breeding and good condition of chicks depend on the time the breeding season for the Puffins start and the amount of Sprat in the diet of young Puffins.
Puffins on St. Kilda start breeding later when the temperature of the sea is warmer. The later the Puffins start to breed, the smaller the breeding success. More Sprat in the diet of Puffin makes the young Puffins heavier.
Whether there is also an influence of predation by the increasing amount of Bonxies in the period, is not considered in the study.

In the "Seabird and Marine Ranger Annual Report St. Kilda 2013" Gina Prior describes a research on breeding success of Puffins she conducted in 2013 on Dùn.
The conclusion of this research is the same; a decline in breeding success and lighter fledglings. This trend is not just seen on St. Kilda, but also on Skomer, Isle of May and Fair Isle, although the breeding success there is better than on St. Kilda.
She doesn't consider the start of the breeding season in her research.

In the pub someone told me he found a pufflin once, but didn't recognise it. Young Puffins are entirely black, and they don't have the distinct white/black head and colourfull bill yet.