Lesser Scaup

Aythya affinis (Eyton, 1838) AY LESSC 2050
Family: Anseriformes > Anatidae

Lesser Scaup, Simon Gillings

Difficult to separate from the more familiar (Greater) Scaup, so the first accepted record of this rare visitor from North America was only in the 1980s. Most arrive in winter but several individuals have stayed on beyond this.

Lesser Scaup chicks are capable of diving under water when they hatch but are too buoyant to stay under. By the time they are five to seven weeks old they can dive for up to 25 seconds and swim underwater for 50 to 60 feet.

Select a topic for more facts and statistics about the Lesser Scaup

8.1k records observations recorded by BTO surveyors
8.1k records



Lesser Scaup identification is often difficult.

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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.


We have no population estimates for this scarce species.


This species is a rare vagrant and was recorded during Bird Atlas 2007–11 as shown on the map.

Occupied 10-km squares in UK


This vagrant has been recorded in several atlases so we have been able to map distribution changes. However, as a rarity these may not show a consistent pattern of change.


Lesser Scaup is a rare vagrant, mostly recorded in winter.

Weekly occurence of Lesser Scaup from BirdTrack
Weekly occurrence patterns (shaded cells) and reporting rates (vertical bars) based on BirdTrack data. Reporting rates give the likelihood of encountering the species each week.


Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.


View a summary of recoveries in the Online Ringing Report.

Foreign locations of birds ringed or recovered in Britain & Ireland

Foreign locations of Lesser Scaup ringed or recovered in Britain & Ireland
Encountered in: Winter (Nov-Feb); Spring (Mar-Apr); Summer (May-Jul); Autumn (Aug-Oct)


Lifecycle and body size information about Lesser Scaup, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.


Sample sizes are too small to report Productivity and Nesting statistics for this species.


For information in another language (where available) click on a linked name

Welsh: Hwyaden Benddu Fechan
Catalan: morell petit
Czech: polák vlnkovaný
Danish: Lille Bjergand
Dutch: Kleine Topper
Estonian: väike-merivart
Finnish: pikkulapasotka
French: Petit Fuligule
German: Kanadabergente
Hungarian: búbos réce
Icelandic: Kúfönd
Irish: Mionlacha Iascán
Italian: Moretta grigia minore
Latvian: maza kerra
Lithuanian: mažoji žiloji antis
Norwegian: Purpurhodeand
Polish: ogorzalka mala
Portuguese: negrelho-americano
Slovak: chochlacka vlnkovaná
Slovenian: ameriška rjavka
Spanish: Porrón bola
Swedish: mindre bergand

Links to more information from ConservationEvidence.com

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