Contrôles par Condition for Bécasseau variable

Most encounters are obtained after the mid-1970s. They come mainly from Jul-Sep – 52% combined (late breeding season and early autumn migration). Most encounters from late Aug to mid-Oct are based primarily on juvenile birds. Majority of encounters (ca. 93%) are recorded in NW, N, C and W Europe (36, 24, 23 and 10% respectively). The encounters based on dead birds decreased markedly over the years: from 74% pre-1960 to 5% after 1991; those based on alive birds considerably increased from 18% before 1960 to 95% after 1991. The latter is mostly due to ringing recoveries and colour mark records. Shooting as а factor has been largely reduced from 56% pre-1960 to less than 1% after 1991.

Most of the distant (>=50 km) recoveries are less than 2000km away (but some are more than 5000km).

Annual Movements for Bécasseau variable

Post-breeding movements start late Jun-Jul, adults preceding juveniles about a month (Delany et al. 2009, Noskov et al. 2016). Autumn migration is evident mostly Aug-Nov, depending on latitude and region. N & NW African coasts are reached as early as Aug, the birds stay in their wintering grounds (S to W Africa) mainly until Mar-Apr, sometimes until mid-May. Major wintering regions in Africa are some coastal habitats in Tunisia, Morocco and from Mauritania to Guinea. 

Breeding sites are usually occupied in Apr-May, those in high Arctic – in Jun.

Tracked birds from the Baltic breeding population used staging sites at Wadden Sea and locally in W Europe to and from their wintering sites in Mauritania, showing rapid jump migration in the autumn and slower skipping type spring migration (Pakanen et al. 2018).

Connectivité par mois par région pour Bécasseau variable

General migration patterns are also supported by genetic evidence – Greenland, Iceland & N European populations are predominant in the W African wintering grounds, while those wintering in W Europe originate from more eastern breeding grounds (e.g. N Russia) (Lopes et al. 2008).

Wadden Sea, Wash (UK), the Baltic Sea and Azov-Black Seas are important moulting grounds for the species (Delany et al. 2009). SW Europe, as well as N & NW Africa serve as stopover and wintering regions for migration routes of broad geographic range (Lopes et al. 2005, Thorup et al. 2009).

Possible loop migration in Europe has been suggested (Bairlein et al. 2014).

Black Sea region spring encounters suggest overland routes across E Europe to the W Siberia, which breeders undertake the longest routes within the region. W Siberian birds are encountered wintering in the Caspian Sea region from late autumn to late spring (Ilichev 1985).