A Census of the Atlantic Puffins Fratercula arctica breeding on Orkney in 2016

Abstract

Atlantic Puffins Fratercula arctica were counted at all known colonies in Orkney (excluding Sule Skerry) during the 2016 breeding season. Counts of individuals (IND) were made during pre-laying and incubation at all 20 sites and at six sites where burrows where physically accessible. In 2016 the Atlantic Puffin population of Orkney was estimated to be 6,675 breeding pairs (based on the counts of apparently occupied burrows [AOB] where available, and assuming that one individual represented one breeding pair for the other sites). AOB counts were higher than the IND counts at all six colonies where both methods were used. Previous Orkney Atlantic Puffin population estimates of breeding pairs were mostly based on counts of individuals on land (INDL) made during late incubation and chick rearing. While caution must be used when comparing INDL counts between years the results suggest a decline in line with studies of other Northern Isles colonies.