Eynhallow

Eynhallow (9.142°N x 3.115°W) is a small uninhabited island within the Orkney Island group off the north of Scotland. It has an area of 0.75 km², and is located in a 3 km wide channel between the larger islands of Mainland Orkney and Rousay.

There are remains of a Norse church on the island, and evidence of regular inhabitation until the mid 1800’s. The island consists of low lying rough grassland and moorland, which is grazed seasonally by sheep, with steeper cliffs on its western side. During the late 1800’s and early 20th century, the island was used for sport shooting and as a holiday retreat by a local estate owner. From the 1930’s, the owners managed the island as an informal bird sanctuary. Orkney Island Council purchased Eynhallow in the 1980’s and the University of Aberdeen has maintained the one remaining house on the island as a seasonal field base for harbour seal and fulmar studies.

The small fulmar colony on Eynhallow has been monitored since 1950. These studies followed the early expansion of this species at Orkney sites, and were facilitated by the birds use of accessible low lying cliffs, old buildings and walls on the island as nest sites. At its peak in the mid-1980s the Eynhallow study colony contained over 200 nests, at a time when the total Orkney population was around 84,000 pairs. More recently, numbers have declined and only 75-100 nests are occupied each year.

Other seabirds breed on the island, but numbers are small and are not closely monitored. These include Puffins, Black Guillemots, Arctic Tern, Great Black-backed Gull, Common Gull, Arctic Skua and Great Skua.

Individual-based studies based upon colour-ringed fulmars have been carried out since 1950. GLS studies were initiated in 2006, resulting in recovered data from >100 individuals, in many cases for multiple years. GPS tracking data during incubation and chick rearing was also conducted on smaller samples of birds between 2009 and 2012.