Anne Cotton

A small colonial cavity-nesting corvid, with a breeding range extending across the whole of Europe (except at high altitudes and latitudes), from the  Mediterranean basin to the Urals  and eastwards to western Mongolia. Mostly resident, only Siberian populations are truly migratory, wintering in W Asia. Three subspecies breed in Europe: monedula in Fennoscandia and C Europe, spermologus in W and S Europe, including the British Isles, and soemmerringii in the NE and SE, eastwards to Siberia.

Season of assessment

B

Population trendIncreasing
Population size
(min-max, best estimate)		17800000-36200000,24700000
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
Mapa

Conectividad global para Grajilla occidental

Most European populations are resident, but there are some winter movements of individuals from populations breeding in N, C and E regions (Waterhouse 1949, Mirski et al. 2011). Overall direction of such movements is to the SW. Most recoveries are short-distance <200 km from ringing site, but there are a few recoveries beyond 1,000 km. Most distant movements are by first-winter individuals. Very few short-distance movements by birds from the W, SW and NW regions, which can be considered sedentary.

Recuperaciones por condición para Grajilla occidental

Most eraly recoveries are of birds found dead, but the recent development of colour-ringing schemes has shifted the balance towards a majority of live resightings. There is still a large proportion of shot-dead recoveries, as Jackdaws are considered to be an agricultural pest in some European countries and regulated as such.

Movimientos anuales para Grajilla occidental

SW  movements from C, E and N Europe towards occur mainly in Oct and Apr, but most individuals, paticularly of the subspecies spermologus and monedula, are resident or disperse locally in winter. Long-distance movements are few and concern northern monedula and eastern soemmerringii. Two tracking studies of spermologus confirm residency and short-distance winter dispersal.

Conectividad por mes por región para Grajilla occidental

Birds breeding in the N move to the SW from early Oct onwards (Kjellén 2019), with winter records mostly along North Sea countries, rarely down to the Mediterranean. Last departures of northern birds from western Europe is in early May. Birds breeding in Central Europe move from mid-Oct onwards, and are back in breeding regions from early Apr. Long-distance recoveries of breeders from E Europe are few, they have been recorded from the end of Oct to mid-Feb, but may well occur over a longer period.

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
Kjellén, N.2019 . Migration counts at Falsterbo, Sweden. Bird Census News 32: 27–37
Mirski P et al.2011 . Winter occurrence of the Jackdaw Corvus monedula subspecies in the selected Polish towns and cities. Acta Polonica 52: 97–106
Waterhouse, M.J.1949 . Rook and jackdaw migration observed in Germany 1942-1945. Ibis 91: 1–16

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