Aron Tanti

Garden Warbler is a long-distance migratory passerine, which breeds in temperate latitudes from W Europe to C Asia; wintering around equatorial Africa (BirdLife International 2021). Insectivorous, though highly frugivorous during the non-breeding period.

Season of assessment

B

Population trendDecreasing
Population size
(min-max, best estimate)		23200000-38900000,30200000
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 Garden Warbler

The many encounters in Africa show parallel migration patterns, which give rise to relatively strong connectivity. W European Garden Warblers winter in W Sahel, while those breeding in N and E European winter in C Africa. Migration occurs in a broad front, with birds migrating over open sea and deserts.

Recoveries by Condition for Garden Warbler

Overall, most (>95%) of recoveries are of birds captured alive, usually in ringing campaigns. However, most recoveries before 1961 were of birds found dead (shot ~25%; other dead, sick or wounded 32%). This pattern clearly changed during 1961-1990, and since 1991 very few birds are reported dead (<2%).

Annual Movements for Garden Warbler

Autumn migration starts in Aug and is widespread across Europe in Aug-Sep. There are encounters in the sub-Saharan belt by Sep. Spring passage in Europe starts in Mar and is obvious in Apr, with the Scandinavian breeding quarters being reached in May.

Connectivity by Month by Region for Garden Warbler

In autumn, fuelling before crossing the Sahara takes place in S Europe, increasing progressively as birds approach the N border of this desert (Biebach 1990). Mediterranean peninsulas/islands are important fuelling areas in autumn (e.g. Fransson et al. 2008). Return from Africa starts in Feb-Mar, with obvious passage in Apr across the entire Mediterranean region, including NW Africa (there are no encounters in NE Africa and the Middle East in Mar-Apr). Migration in spring is very fast, thanks to fuelling in equatorial Africa (Pilastro & Spina 1997).  Birds start to arive on the breeding grounds in C and W Europe in Apr.

Juan Arizaga

References

Statistics Map
N records N individuals N recoveries
Mapped data*
Total available data
*Mapped data include only distant (>= 50 km) recoveries
References Map
Biebach, H.1990 . Strategies of trans-Saharan migrants. In: E. Gwinner (Eds.), Bird migration. Springer Heidelberg, Berlin: 352–367
BirdLife International 2021 . Species factsheet: Sylvia borin.
Fransson, T., Barboutis, C., Mellroth, R., Akriotis, T.2008 . When and where to refuel before crossing the Sahara desert - extended stopover and migratory fuelling in first-year garden warblers Sylvia borin. Journal of Avian Biology 39: 133–138
Pilastro, A., Spina, F.1997 . Ecological and morphological correlates of residual fat reserves in passerine migrants at their spring arrival in Southern Europe. Journal of Avian Biology 28: 309–318

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