Rob Robinson

A colonial corvid with a breeding distribution covering most of Europe, except Mediterranean and Arctic climates. In Fennoscandia, restricted to the SW and W coast of Finland. N European and Russian populations are migratory, spreading across more S latitudes from N Spain to Turkey in winter (Waterhouse 1949), although this is not reflected in the recovery map which shows most birds in W Europe.

Season of assessment

B

Population trendDecreasing
Population size
(min-max, best estimate)		11400000-21300000,15000000
Red List categoryVU
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
Mapa

Conectividad global para Graja

Most recovery distances are short, up to 1,000 km - some are dispersal. Migration is NE-SW, with birds breeding in European Russia moving to C, NW and W Europe in winter. Birds from Scandinavia mainly move to Denmark. Those from the British Isles disperse locally (Patterson et al. 1971, Wernham et al. 2002), as do birds from S Russia and the Caucasus. There is no evidence of age- or sex-specific migration strategies. There are a few data from satellite-tracking in Israel. Most spent the breeding season in Turkey, one in S Russia (Astrakhan), moved N in early Mar and arrived on the breeding grounds mid-Mar-mid-Apr. Breeders from Turkey left at the end of Oct and reached Israel in early Nov, starting to move N at the end of Feb and arriving on the breeding grounds in mid-Mar.

Recuperaciones por condición para Graja

Over half of recoveries are of dead birds (>56%), most of which have been shot for different reasons (not generally explained; 19% of all recoveries), including crop protection and nature conservation. There was a switch to a majority of birds reported alive (75%) after 1990, including a large proportion of recaptures by ringers. This introduces different biases to the data before and after 1990.

Movimientos anuales para Graja

Birds breeding in the British Isles remain for the winter, as do those in W Europe. Most birds from the E and C populations move SW from early Sep-Nov, although some remain in their breeding region in winter. In Scandinavia, breeding grounds are almost empty Dec-Jan; most birds have left the wintering grounds by May, and the first non-breeding records in the winter quarters are in Oct.

Conectividad por mes por región para Graja

Migratory populations are present on their N breeding grounds as early as Mar, while late birds leave the wintering grounds in W Europe in May. Mar-Apr are the main months when wintering Rooks move progressively NE, most being on the breeding grounds in May. After the breeding season, movements to the SW are mainly in Oct, with some in early Nov. The same applies to breeding birds from N, C and E Europe.

Referencias

Estadísticas Mapa
Nº de registros Nº de individuos Nº de recuperaciones
Datos en el mapa*
Total de datos disponibles
* Los datos del mapa incluyen solo recuperaciones lejanas (>= 50 km)
Referencias Mapa
2002 . The Migration Atlas: movements of the birds of Britain and Ireland. T. & A.D. Poyser, LondonEditor(s): Wernham, C.V., Toms, M.P., Marchant, J.H., Clark, J.A., Siriwardena, G.M., Baillie, S.R.
Patterson, I. J., Dunnet, G. M., & Fordham, R. A.1971 . Ecological Studies of the Rook, Corvus frugilegus L., in North-East Scotland. Dispersion. Journal of Applied Ecology 8 Link to Article (DOI: https://doi.org/10.2307/2402685) : 815–833
Waterhouse, M.J.1949 . Rook and jackdaw migration observed in Germany 1942-1945. Ibis 91: 1–16

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