Recoveries by Condition for Black Guillemot

Game species in Iceland and Greenland, protected species in most of Europe.

N & NW Europe account for most of the encounters – ca. 86 and 11% respectively. Most encounters (ca. 67%) come from the period Jun-Jul, mainly due to juveniles ringed. Encounters based on dead birds decreased from 90% pre-1960 to 54% after 1991; those based on alive birds increased from 3% before 1960 to 42% after 1991. The latter is mostly due to ringing recoveries. Shooting was an important factor mainly in the past – 45% of all cases pre-1960, currently these cases account for less than 1%. Nowadays 15% of all recoveries come from by-catch casualties (40% in 1961-1990). Vulnerable to oil pollution (Wernham et al. 2002).

Most of the distant (>=50 km) recoveries are spread primarily throughout the Baltic region and the British Isles.

Annual Movements for Black Guillemot

Post-breeding dispersal starts in Aug. The species undergoes a flightless wing-moulting period after breeding season (Butler et al. 2020).

Icelandic breeders take either SW routes to overwinter in SW Greenland (Dec) or head W towards E Greenland where encountered Sep-Nov, joining the wintering local population (Lyngs 2003). British Isles population is primarily sedentary, dispersing locally – most encounters are from the Irish Sea and Orkney/ Shetland regions. Barents Sea population is largely resident (Flint, Golovkin, 1989; Noskov et al. 2016), but a juvenile from NW Russia was found wintering in C Norway (Nov). S Fennoscandian and Baltic Sea region breeders are mostly local dispersers, some reaching W France (Dec) & British Isles (Feb) during winter. Juvenile from the Finnish population was found wintering inland – SW Russia (Feb), close to Volga River.

Connectivity by Month by Region for Black Guillemot

Dispersal movements after the breeding season start in late summer. Icelandic population takes SW & W routes to winter in SW & E Greenland (encounters from early autumn to early winter). Birds breeding in the British Isles are largely sedentary and locally dispersive.

N European population (Norway, Russia) is mostly resident, but overwintering birds are encountered along the coast of C & SW Norway from mid-autumn to mid-winter. Birds breeding in S Scandinavia and the Baltic Sea region are mainly sedentary, some spreading to France and UK (mid- to late winter records).

Return to breeding sites takes place from early to late spring, depending on the latitude and sea ice conditions.

The species is known to be philopatric, but levels of philopatry and dispersal distance varies between colonies (Frederiksen, Petersen, 1999; Johnston et al. 2018).