Lesser Scaup

Aythya affinis

Introduction

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.

Key Stats

Status

Rare

Weight

800g

Seasonality

<1%

BTO Records

8.1k records

Population and distribution stats for:

No data

No current data

No current data

No data

No current data

% expansion

Status and Trends

Population size, trends and patterns of distribution based on BTO and partnership surveys and atlasses with data collected by BTO volunteers.

Conservation Status

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This species can be found on the following statutory and conservation listings and schedules.

IUCN Red List of Threatened Species (global)

Least Concern

Schedule 1 Licence required (to disturb)*

Birds Directive Annex 1

* A guide only. Check details with the original legislation, especially those marked with an asterisk. See About Birdfacts for more information.

Population Size

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BOU Category

Source

First Record*

Staffordshire, 1987

* First documented occurrence. Most species undoubtedly occurred before this. See About Birdfacts for more information.

Population Change

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Population trends of this scarce species are not routinely monitored.

Distribution

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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

These figures come from Bird Atlas 2007 and indicate how widespread a species is.

No. occupied in winter

% occupied in winter

Bird Atlas distribution maps show where bird species breed or winter in Britain and Ireland. For breeding maps, larger dots indicate higher certainty the species bred in that area.

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

To view and download up-to-date distribution information aggregated from across BTO and partnership surveys and schemes, see our data holdings on the NBN Atlas.

Distribution Change

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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.

Bird Atlas distribution change maps show how bird distributions have changed through time. Coloured upward-pointing triangles show places apparently colonised over the period; grey downward-pointing triangles show places apparently vacated. Shading show places occupied.

Winter Distribution change for Lesser Scaup

Click the map to enlarge,
or view it on Bird Atlas Mapstore.

Seasonality

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

Weekly pattern of occurrence

The graph shows when the species is present in the UK, with taller bars indicating a higher likelihood of encountering the species in appropriate regions and habitats.

Phenology graph — 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.

Movement

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

Britain & Ireland movement

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View a summary of recoveries in the Online Ringing Report

Foreign locations of birds ringed or recovered in Britain & Ireland

Dots show the foreign destinations of birds ringed in Britain & Ireland, and the origins of birds ringed overseas that were subsequently recaptured, resighted or found dead in Britain & Ireland. Dot colours indicate the time of year that the species was present at the location.

Winter (Nov-Feb)
Spring (Mar-Apr)
Summer (May-Jul)
Autumn (Aug-Oct)

Foreign locations of birds ringed or recovered in Britain & Ireland

European movements

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EuroBirdPortal uses birdwatcher's records, such as those logged in BirdTrack to map the flows of birds as they arrive and depart Europe. See maps for this species here.

Biology

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

Survival and Longevity

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Survival is shown as the proportion of birds surviving from one year to the next and is derived from bird ringing data. It can also be used to estimate how long birds typically live.

View number ringed each year in the Online Ringing Report.

Classification, names and codes

Taxonomy, names and species codes for Lesser Scaup

Classification and Codes

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Order: Anseriformes
Family: Anatidae
Scientific name: Aythya affinis
Authority: Eyton, 1838

BTO 2-letter code: AY
BTO 5-letter code: LESSC
Euring code number: 2050

Alternate species names

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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
Welsh: Hwyaden Benddu Fechan

More Evidence

More evidence from Conservation Evidence.com

Partners

Birdfacts is based on data collected by volunteers participating in surveys that are organised and funded by BTO, RSPB, Esmée Fairbairn Foundation, JNCC and other partners.

BTO

Esmée Fairbairn Foundation

JNCC

RSPB

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