Aythya marila (Linnaeus, 1761)
Family: Anseriformes > Anatidae
This black and white diving duck is a winter visitor to the loughs, lochs and shallow inshore waters of the UK.
Scaup begin arriving in Britain & Ireland during the second half of October from breeding grounds in Iceland, Scandinavia and western Russia. Numbers continue to build throughout the winter months and, as might be expected, birds from the western part of their range largely occur in western Britain and those from the east in eastern Britain.
The Wetland Bird Survey shows that around 3,000 Scaup winter in the UK with the largest gatherings found in Northern Ireland and Scotland. Individuals begin to head back to their breeding grounds in March. Breeding occurs in the UK only sporadically, only involving one or two pairs in any given year.
Select a topic for more facts and statistics about the Scaup
Scaup identification is sometimes difficult. The following article may help when identifying Scaup.
Dabbling ducks are so familiar, but there is also a group of common ducks that actively dive on freshwater for food. One or other is likely to be encountered on still or moving freshwater or even at sea so let this workshop help you to decide which diving duck you are seeing.
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Status and Trends
Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.
This species can be found on the following statutory and conservation listings and schedules.
|UK winter population||-66% decrease (1995/96 to 2020/21)|
Scaup occupy a wide range of coastal and inland areas, though the greatest numbers are found on the coast in northern and western Britain and northeastern and southwestern Ireland.
Occupied 10-km squares in UK
|No. occupied in breeding season||5|
|% occupied in breeding season||0.2|
|No. occupied in winter||669|
|% occupied in winter||22|
European Distribution Map
Scaup winter range has exanded by 57% since the 1981–84 Winter Atlas with gains in some coastal areas, including the Northern Isles, Moray Firth and southwest England, and also at inland sites. This contrasts with a marked population reduction, especially in Ireland.
Change in occupied 10-km squares in the UK
|% change in range in breeding season (1968–72 to 2008–11)||-37.5%|
|% change in range in winter (1981–84 to 2007–11)||+56.4%|
Scaup is a localised winter visitor, present from September to March, though some birds occasionally summer.
Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.
Lifecycle and body size information about Scaup, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.
View number ringed each year in the Online Ringing Report
|Maximum Age from Ringing||8 years 4 months 30 days (set in 1971)|
|Typical Lifespan||3 years with breeding typically at 2 year|
|Field Codes||2-letter: SP | 5-letter code: SCAUP | Euring: 2040|
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