Brünnich's Guillemot recolonises breeding site after 40-year absence

Brünnich's Guillemot has recolonised a former breeding site in Greenland following a 40-year absence to the surprise of conservationists, with the nearest extant colony some 150 km away.

The site at Salleq, in the west of the territory, supported an estimated 500,000 birds in 1920 and 150,000 in 1949, making it one of the largest in west Greenland. 

However, a drastic decline followed, with merely 4,500 recorded in 1975 and, by 1984, only 150. By 1987, a paltry 50 birds were logged, with the site deserted by 1990. Excessive hunting and fishing bycatch were thought to be the main drivers behind this decline.

Brünnich's Guillemot forms vast breeding colonies, sometimes comprised of more than a million breeding birds, on narrow ledges and steep cliffs (Ed Stubbs).

Back from the brink

Fast-foward to 2022 when a local skipper, Paaluk Kreutzmann, reported sightings of Brünnich's Guillemots on the water below the seabird cliff at Salleq. This observation was confirmed on 10 August 2022 when 30 adults and at least two large chicks were observed on five ledges in a discrete area of the Salleq cliff, surrounded by at least 1,000 Kittiwake nests and 15 Razorbills – both species that too had abandoned the site. This remarkable return was documented in The Seabird Group's journal, Seabird.

It is unclear where these Brünnich's Guillemots have come from. The nearest thriving colonies in Greenland are 150 km further north in the Upernavik district, with others at Innaq in Disko Bay (270 km south of Salleq, at sea distance), and Kingittoq near Upernavik (275 km north of Salleq). Both colonies are declining and it is questionable whether they are producing enough offspring to be capable of establishing a new breeding site. Indeed, the nearest thriving colonies in Greenland are 150 km further north in the Upernavik district. 

However, it's thought the birds may have arrived from the Canadian side of Baffin May – more than 600 km away – where colonies are stable. Birds ringed at these colonies have been seen elsewhere in Greenland.

Reference

Boertmann, D. 2023. Re-establishment of an extinct breeding colony of Brünnich’s Guillemot Uria lomvia in West Greenland. Seabird. DOI: doi.org/10.61350/sbj.35.4