Gunther Zieger

A diving duck with a high latitude, circumpolar breeding distribution, restricted in Europe to the Nordic countries and Siberian Russia. Winters mainly at sea or on coastal eutrophic lagoons in W and N Europe, with very small numbers on inland lakes in C Europe and along Mediterranean coasts. The European wintering population of Greater Scaup has declined significantly over the last 20 years, apparently because of short stopping and changes in food resources on the wintering grounds  (Cervencl & Fernandez 2012, Marchowski et al. 2020).

Season of assessment

B

Population trendDecreasing
Population size
(min-max, best estimate)		96400-170000,128000
Red List categoryLC
Franks, S., Fiedler, W., Arizaga, J., Jiguet, F., Nikolov, B., van der Jeugd, Ambrosini, R, Aizpurua, O., Bairlein, F., Clark, J., Fattorini, N, Hammond, M., Higgins, D, Levering, H., Skellorn, W., Spina, F, Thorup, K. Walker, J., Woodward, I. and Baillie, S.R. (1) (2022) Online Atlas of the movements of European bird populations. https://migrationatlas.org EURING/CMS (1) Principal investigator
Map

Overall Connectivity for Greater Scaup

The distribution of recovery distances is quite uniform from few 100 to few 1,000 km, illustrating the short- to long-distance movements of the species in winter. These movements are mainly orientated from Iceland to the SE to reach W Europe (British Isles and the N Sea), and from the Baltic Sea and Siberian Russia to the SW, mainly to reach the Wadden Sea. There are no obvious sex- or age-specific patterns. Most recoveries are from the 1970s-1990s,. There has been minimal ringing effort in recent years during the period of decline, so the patterns deduced from ringing data are based upon recovery data obtained decades ago. 

Recoveries by Condition for Greater Scaup

The majority of recoveries across the periods are of dead birds (~82%), even during the decades providing numerous recoveries (80%). Recent records are very few and are almost all (~93%) of dead birds, illustrating that this declining diving duck is still hunted in some European countries.

Annual Movements for Greater Scaup

Greater Scaup of varying summer provenance start to move back to the breeding grounds in Apr, where females with their offspring remain into late summer. Males leave the breeding gounds on moult migration, where they remain in Aug-Sep, before all age and sex classes begin to move to the winter quarters in Oct. This is a species about which we know very little, especially as our understanding based on patterns obtained from recoveries is heavily influenced by the timing and distribution of hunting activities.

Connectivity by Month by Region for Greater Scaup

The recoveries of Icelandic birds in the British Isles and adjacent continental European coasts are in Oct-Feb i.e. mainly during the hunting season, with a few in late summer. Birds from the Baltic Sea reach the N Sea in Sep, although some arrive in late Jul, with the latest record in March. Siberian birds are present on their breeding grounds from May onwards, although some are still present on the wintering grounds in Apr. There are a few recoveries in Arctic bays (e.g. Pechora) in Sep, probably of birds that moulted there, and as late as Oct from Russia, but recoveries from Nov onwards are only from the wintering sites from N Sea coasts to Spain.

Frédéric Jiguet

References

Statistics Map
N records N individuals N recoveries
Mapped data*
Total available data
*Mapped data include only distant (>= 50 km) recoveries
References Map
Cervencl, A., Fernandez, S.A.2012 . Winter distribution of Greater Scaup Aythya marila in relation to available food resources. Journal of Sea Research 73 Link to Article (DOI: https://doi.org/10.1016/j.seares.2012.06.006) : 41–48
Marchowski, D., Ławicki, L., Fox, A.D., Nielsen, R.D., Petersen, I.K., Hornman, M., Nilsson, L., Haas, F., Wahl, J., Kieckbusch, J., Nehls, H.W., Calbrade, N., Hearn, R., Meissner, W., Fitzgerald, N., Luigujoe, L., Zenatello, M., Gaudard, C. et al.2020 . Effectiveness of the European Natura 2000 network to sustain a specialist wintering waterbird population. Scientific Reports 10 article no.: 20286

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