Gavia arctica -- (Linnaeus, 1758)ANIMALIA -- CHORDATA -- AVES -- GAVIIFORMES -- GAVIIDAECommon names: Arctic Loon; Black-throated Diver; Black-throated Loon

European Red List AssessmentEuropean Red List Status

LC -- Least Concern, (IUCN version 3.1)

Assessment InformationYear published: 2015Date assessed: 2015-03-31Assessor(s): BirdLife InternationalReviewer(s): Symes, A.Compiler(s): Ashpole, J., Burfield, I., Ieronymidou, C., Pople, R., Wheatley, H. & Wright, L.Assessment RationaleEuropean regional assessment: Least Concern (LC)EU27 regional assessment: Least Concern (LC)

In Europe this species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern in Europe.

Within the EU27 this species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern in the EU27.

OccurrenceCountries/Territories of OccurrenceNative:Albania; Austria; Azerbaijan; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Czech Republic; Denmark; Estonia; Finland; France; Georgia; Germany; Greece; Hungary; Ireland, Rep. of; Italy; Latvia; Lithuania; Macedonia, the former Yugoslav Republic of; Moldova; Montenegro; Netherlands; Norway; Svalbard and Jan Mayen (to NO); Poland; Romania; Russian Federation; Serbia; Slovakia; Slovenia; Spain; Sweden; Switzerland; Turkey; Ukraine; United KingdomVagrant:Armenia; Faroe Islands (to DK); Luxembourg; Portugal; Canary Is. (to ES); Gibraltar (to UK)

PopulationThe European population is estimated at 53,800-87,800 pairs, which equates to 108,000-176,000 mature individuals. The population in the EU27 is estimated at 17,500-20,400 pairs, which equates to 35,000-40,700 mature individuals. For details of national estimates, see Supplementary PDF.

TrendIn Europe the population size is estimated to be decreasing by less than 25% in 29.4 years (three generations). In the EU27 the population size is estimated to be stable. For details of national estimates, see Supplementary PDF.

Habitats and EcologyThis specialist breeds on deep, productive, freshwater lakes (Carboneras and Garcia 2014) or extensive pools with islets, peninsulas and other inaccessible nesting sites (Snow and Perrins 1998). Outside of the breeding season the species is most common on inshore waters along sheltered coasts (Carboneras and Garcia 2014),

occasionally also frequenting large inland freshwater bodies (Flint et al. 1984, Carboneras and Garcia 2014) such as natural lakes or barrages, lagoons and large rivers (Snow and Perrins 1998). It breeds in isolated solitary pairs (Snow and Perrins 1998, Carboneras and Garcia 2014) from April onwards (Flint et al. 1984), although nesting occurs later further to the north depending on the timing of the thaw. The nest is a heap of plant matter placed near the water's edge (Carboneras and Garcia 2014) on islets or hummocks emerging from the water, sometimes also on clumps of grass on the shore (Flint et al. 1984). Clutches are almost always two. Its diet consists predominantly of fish although aquatic insects, molluscs, crustaceans and some plant matter may also be taken. This species is migratory and dispersive, generally moving south post-breeding (Carboneras and Garcia 2014).Habitats & Altitude

Habitat (level 1 - level 2) Importance OccurrenceMarine Neritic - Estuaries suitable non-breedingMarine Neritic - Macroalgal/Kelp major non-breedingMarine Neritic - Pelagic suitable non-breedingMarine Neritic - Seagrass (Submerged) major non-breedingMarine Neritic - Subtidal Loose Rock/pebble/gravel major non-breedingMarine Neritic - Subtidal Rock and Rocky Reefs major non-breedingMarine Neritic - Subtidal Sandy major non-breedingMarine Neritic - Subtidal Sandy-Mud major non-breedingWetlands (inland) - Permanent Freshwater Lakes (over ha) major breedingAltitude max. 500 m Occasional altitudinal limits

ThreatsDuring the breeding season the species is threatened by the acidification of breeding waters, heavy metal pollution and water level fluctuations (Carboneras and Garcia 2014) especially during the incubation period (Gotmark et al. 1989, Hake et al. 2005). It also suffers from lower reproductive success due to human disturbance (Carboneras and Garcia 2014) (e.g. from tourists or wetland visitors) (Gotmark et al. 1989) and is indirectly affected by breeding habitat alteration (e.g. afforestation) (Carboneras and Garcia 2014). During the winter the species is highly vulnerable to coastal oil spills, especially in rich fishing grounds where large congregation may occur, and is commonly caught and drowned as bycatch in fishing nets (Carboneras and Garcia 2014). The species is also highly sensitive to disturbance from coastal wind farms (wind turbines) (Garthe and Huppop 2004) and is susceptible to avian influenza so may be threatened by future outbreaks of the virus (Melville and Shortridge 2006).Threats & Impacts

Threat (level 1) Threat (level 2) Impact and StressesAgriculture & aquaculture

Agro-industry plantations

Timing Scope Severity ImpactOngoing Majority (50-90%) Slow, Significant

DeclinesMedium Impact

StressesEcosystem conversion; Ecosystem degradation

Biological resource use

Fishing & harvesting aquatic resources (unintentional effects: (subsistence/small scale) [harvest])

Timing Scope Severity ImpactOngoing Majority (50-90%) Slow, Significant

DeclinesMedium Impact

StressesSpecies mortality

Biological resource use

Hunting & trapping terrestrial animals (intentional use - species is the target)

Timing Scope Severity ImpactOngoing Majority (50-90%) Negligible declines Low Impact

StressesSpecies mortality

Climate change & severe weather

Habitat shifting & alteration

Timing Scope Severity ImpactFuture Whole (>90%) Unknown Unknown

StressesEcosystem degradation; Indirect ecosystem effects

Energy production & mining

Renewable energy Timing Scope Severity ImpactOngoing Majority (50-90%) Negligible declines Low Impact

StressesSpecies mortality

Threats & ImpactsThreat (level 1) Threat (level 2) Impact and Stresses

Human intrusions & disturbance

Recreational activities

Timing Scope Severity ImpactOngoing Majority (50-90%) Negligible declines Low Impact

StressesSpecies disturbance; Reduced reproductive success

Invasive and other problematic species, genes & diseases

Avian Influenza Virus (H subtype)

Timing Scope Severity ImpactPast, Likely to Return

Majority (50-90%) Slow, Significant Declines

Past Impact

StressesSpecies mortality

Pollution Industrial & military effluents (type unknown/unrecorded)

Timing Scope Severity ImpactOngoing Majority (50-90%) Slow, Significant

DeclinesMedium Impact

StressesEcosystem degradation

Pollution Oil spills Timing Scope Severity ImpactOngoing Majority (50-90%) Slow, Significant

DeclinesMedium Impact

StressesEcosystem degradation

ConservationConservation Actions UnderwayCMS Appendix II (Gavia arctica arctica). EU Birds directive Annex I. Bern Convention Appendix II. Artificial nesting areas have been created to improve breeding success of this species and in Sweden nesting islands and the surrounding areas have been included in sanctuaries (Sibley and Monroe 1990).

Conservation Actions ProposedKey breeding sites should be identified and site protection implemented against development and human disturbance. Tighter legislation should be developed as well as penalties (national and international) associated with oil pollution from offshore developments and transport. Promote the proper use of corrective measures in longline fisheries to avoid accidental capture of birds.

BibliographySibley, C.G. and Monroe, B.L. (1990) Distribution and Taxonomy of the Birds of the World. Yale University, Connecticut.Carboneras, C. & Garcia, E.F.J. (2014). Arctic Loon (Gavia arctica). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/52474 on 22 January 2015).Flint, V. E.; Boehme, R. L.; Kostin, Y. V.; Kuznetsov, A. A. 1984. A field guide to birds of the USSR. Princeton University Press, Princeton, New Jersey.Garthe, S.; Hüppop, O. 2004. Scaling possible adverse effects of marine wind farms on seabirds: developing and applying a vulnerability index. Journal of Applied Ecology 41(4): 724-734.Götmark, F.; Neergaard, R.; Åhlund, M. 1989. Nesting ecology and management of the Arctic Loon in Sweden. Journal of Wildlife Management 53: 1025-1031.Hake, M.; Dahlgren, T.; Ahlund, M.; Lindberg, P.; Eriksson, M. O. G. 2005. The impact of water level fluctuation on the breeding success of the black-throated diver Gavia arctica in south-west Sweden. Ornis Fennica 82(1): 1-12.Melville, D. S.; Shortridge, K. F. 2006. Migratory waterbirds and avian influenza in the East Asian-Australasian Flyway with particular reference to the 2003-2004 H5N1 outbreak. In: Boere, G.; Galbraith, C., Stroud, D. (ed.), Waterbirds around the world, pp. 432-438. The Stationary Office, Edinburgh, UK.Snow, D. W.; Perrins, C. M. 1998. The Birds of the Western Palearctic vol. 1: Non-Passerines. Oxford University Press, Oxford.

Map (see overleaf)