Michele Mendi

The species occupies for breeding various types of freshwater or brackish wetlands (both natural and artificial), usually large and shallow, with abundant emergent and submergent vegetation (Keller et al. 2020). It has wide distribution across the Holarctic: W & C North America, from Iceland and most of Europe to Japan and Kamchatka, locally in NW Africa (Leschack et al. 2020).

Eurasian-African/Asian migrant. Strongly migratory in the N of its range, the populations in temperate regions largely resident, like in W & S Europe.

Its population trend in Europe is increasing. Evaluated as “Least Concern” (BirdLife International 2021).

Season of assessment

B

Population trendIncreasing
Population size
(min-max, best estimate)		164000-262000,202000
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 Gadwall

General movement pattern in migratory populations follows NE – SW direction. Breeding birds from Fennoscandia, Denmark, the Baltic region, NW Russia and most of those from C Europe migrate towards W & SW Europe and W Mediterranean (exceptionally NW Africa) for wintering. Birds wintering in the Black Sea and E Mediterranean region originate mainly from E Europe/ European Russia, and also partly from C Europe, while those in the Caspian Sea region – from W Siberia. Icelandic population travels SE to winter around the British Isles where it joins part of the local birds; the remaining birds breeding in UK and Ireland move towards W Europe. C Mediterranean region holds mostly migrants from C Europe. W European populations (France, Iberian Peninsula) are largely sedentary or locally dispersive.

Recoveries by Condition for Gadwall

Game species in some European countries. Most encounters are obtained from the mid-1970s to 1991 and after 2004. The encounters are almost equally spread throughout the year, except for the period Mar-May which produced the lowest number of them; a single peak is evident in Jan (ca. 15% of all encounters). NW Europe holds the bulk of encounters (37%), followed by W and C regions (ca. 19% each). The encounters based on dead birds (mostly as a result of shooting/ hunting) fluctuated over time (49% pre-1960, 82% in 1961-1990, and 34% after 1991), while those based on alive birds – markedly increased (from 4% pre-1960 to 65% after 1991). The latter is largely due to ringing recoveries and identification from a distance (wing tags) – coming mostly from W & C Europe.

Annual Movements for Gadwall

The breeding grounds are left by males in early Jul, preceding the females and young about a month (Scott, Rose, 1996). The species undergoes a flightless wing-moulting period in late summer at suitable locations (Leschack et al. 2020) – moulting concentrations are known from W & C Europe and Volga Delta, before the birds continue to their wintering grounds (Scott, Rose, 1996).

Autumn movements take place as early as Sep, mostly in Oct-Nov; the final wintering sites are usually reached by Dec. Small number of encounters exists from coastal wetlands in N Africa between Nov and Feb. Return movements in spring take place mostly in Mar-Apr. Single birds remain in their wintering areas until May.

Although the timing of the breeding season varies geographically the species typically nests later than other Anatini (Leschack et al. 2020).

Connectivity by Month by Region for Gadwall

Males, non-breeding females and failed breeders perform moult migrations starting from mid-summer; the successfully breeding females moult near brood-rearing areas (Leschack et al. 2020). Satellite tagging of birds from a moulting location to an autumn staging site in C Europe revealed multidirectional movements (Gehrold et al. 2014). Autumn migration is evident from the start of the season but is more intensive mid- to late autumn. The wintering grounds are normally occupied in early winter. Some birds overwinter as far S as N Africa and Tigris-Euphrates river system. Return migration takes place mostly early- to mid-spring, the breeding sites in the extreme N of species range can be reached in late spring (Noskov et al. 2016).

Boris Nikolov

References

Statistics Map
N records N individuals N recoveries
Mapped data*
Total available data
*Mapped data include only distant (>= 50 km) recoveries
References Map
2020 . European Breeding Bird Atlas 2: Distribution, Abundance and Change. European Bird Census Council & Lynx Edicions, BarcelonaEditor(s): Keller, V., S. Herrando, P. Voříšek, et al.
BirdLife International2021 . Species factsheet: Mareca strepera. Downloaded from http://www.birdlife.org on 27/07/2021.
Gehrold, A., Bauer, H. G., Fiedler, W., Wikelski, M. 2014 . Great flexibility in autumn movement patterns of European gadwalls Anas strepera. J Avian Biol. 45: 131–139
Leschack, C. R., S. K. McKnight, and G. R. Hepp 2020 . Gadwall (Mareca strepera), version 1.0. In Birds of the World Link to Article (DOI: https://doi.org/10.2173/bow.gadwal.01) Cornell Lab of Ornithology, Ithaca, NY, USA
Noskov, G. A., Rymkevich, T. A., Gaginskaya, A. R. 2016 . Migration of Birds on Northwest Russia. Non-Passerines. ANO LA “Professional”, Saint Petersburg
Scott, D. A., Rose, P. M. 1996 . Atlas of Anatidae Populations in Africa and Western Eurasia. Wetlands International , Wageningen, The Netherlands

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