|Scientific Name:||Bucephala islandica (Gmelin, 1789)|
|Taxonomic Source(s):||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Facilitator/Compiler(s):||Ashpole, J, Butchart, S., Calvert, R., Ekstrom, J.|
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
|Previously published Red List assessments:|
|Range Description:||The major breeding range of this species is along the western coast of the U.S.A. from southern Alaska to northern California. Breeding colonies are also found in Labrador (Canada), south-west Greenland (to Denmark) and Iceland. Some populations (e.g. Iceland) are sedentary, whereas others undertake longer trips to winter along the Pacific coast of Alaska and Canada, and the north-eastern coast of North America (del Hoyo et al. 1992).|
Native:Canada; Iceland; United States
Vagrant:Czech Republic; Faroe Islands; France; Germany; Korea, Republic of; Montenegro; Norway; Russian Federation (European Russia); Serbia; Spain; Svalbard and Jan Mayen; United Kingdom
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The European population is estimated at 800-900 pairs, which equates to 1,600-1,800 mature individuals (BirdLife International 2015). However Europe represents <5% of the global range.|
Trend Justification: This species has undergone a large and statistically significant increase over the last 40 years in North America (171% increase over 40 years, equating to a 28.3% increase per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). The European population trend is unknown (BirdLife International 2015).
|Current Population Trend:||Increasing|
|Habitat and Ecology:||This species breeds on freshwater lakes, pools and rivers in open or wooded country. It can be seen nesting as high as 3,000 m in the Rocky Mountains (U.S.A.). The species uses relatively productive lakes and rivers in Iceland. It is a hole-nesting species using natural holes in lava fields and nest boxes erected on farmhouses at the edge of the breeding area (Tucker and Heath 1994). Laying is usually from mid-May although slightly earlier if using nest boxes. It lays 8 to 11 eggs (Carboneras and Kirwan 2016). It feeds mainly on benthic invertebrates (Tucker and Heath 1994). It is largely sedentary in Iceland (Carboneras and Kirwan 2016). Summer foods include insects and their larvae and plant material, whereas winter diet consists mainly of molluscs and crustaceans (del Hoyo et al. 1992). The species is not truly migratory, with some populations mostly sedentary and others moving distances of >1,000 km (Carboneras and Kirwan 2016).|
|Systems:||Terrestrial; Freshwater; Marine|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Generation Length (years):||8.1|
|Movement patterns:||Full Migrant|
|Congregatory:||Congregatory (and dispersive)|
|Major Threat(s):||In Europe this species is mainly confined to NE Iceland, where 85–90% of the local population occurs at Lake Mývatn and on the River Laxá, and c. 50% of population disappeared in 1989 due to a crash in foraging resources (Carboneras and Kirwan 2016). Plans to introduce Atlantic salmon (Salmo salar) into the river system (Einarsson and Magnúsdóttir 1993), along with sediment dredging that occurs, could negatively affect future food availability (Kear 2005). Eggs are harvested by local people but this is considered sustainable as each nest is subject to a quota. There is a comparatively large sexual imbalance in the Icelandic population with rarely more than 400 females available in any given breeding season (Carboneras and Kirwan 2016). Forestry regulations that do not promote the retention of either large trees or older forests reduces the availability of potential nest cavities (Robert et al. 2010). The species is hunted in North America although overall numbers harvested are not great. Northern Pacific populations are known to be susceptible for short-periods to broad-scale oceanic regime changes (Carboneras and Kirwan 2016).|
Conservation Actions Underway
Bern Convention Appendix II. CMS Appendix II. Listed as Endangered on Icelandic National Red List (Institute of Natural History 2000). The species is fully protected from hunting in Iceland (Carboneras and Kirwan 2016).
Conservation Actions Proposed
Research should be undertaken into the species's ecology, habitat and foraging needs. An assessment of the impacts of S. salar introduction and sediment dredging should be made as well as ensuring the sustainability of local egg harvesting. Research studies into the causes of the population sexual imbalance should be developed.
|Citation:||BirdLife International. 2016. Bucephala islandica. The IUCN Red List of Threatened Species 2016: e.T22680459A89366763.Downloaded on 22 October 2017.|
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