Movements and Migration

A four-year study of post-fledging movements in southern Norway in Great Tit and Eurasian Blue Tit (Cyanistes caeruleus), with data pooled between species, found that family groups moved a mean distant from the nest of 134 m (range 6–1,036 m) and 4.8 m (range -23 to +69 m) upslope. The upslope movements could represent tracking a phenological gradient of delayed plant and insect growth at higher elevations, but territory defense may also play a larger role in restraining post-fledging movements (80 Slagsvold, T., A. Eriksen, R. M. De Ayala, J. Husek, and K. L. Wiebe (2013). Postfledging movements in birds: do tit families track environmental phenology? Auk 130(1):36–45. Close ).

Data summarized from Cramp and Perrins (19 Cramp, S., and C. M. Perrins, Editors (1993). The Birds of the Western Palearctic. Volume 7. Flycatchers to shrikes. Oxford University Press, Oxford, UK. Close ), unless otherwise stated.

Resident, altitudinal migrant, and partially irruptive. In central and southern Europe largely sedentary, but also eruptive in autumns when population high (and often when beech crop (Fagus sylvatica) poor and in conjunction with other factors).

In late summer and autumn, dispersing flocks of juveniles (which can include some only ca. 1 week out of nest) wander in random manner usually within a short distance of breeding range (second-brood young generally moving farther than those fledged earlier), but may gather in larger numbers at favorable feeding localities; by late autumn or early winter numbers within flocks usually reduced by ca. 50% through death or emigration, and flock usually more settled in area that it will occupy throughout winter. Adults (especially males) remain on breeding territory throughout year if conditions permit (including in areas of northwest Siberian taiga), but may join flocks for short periods in midwinter, especially when flocks pass through territory (in late winter, males more likely to remain within their territory in preparation for breeding season).

Evidence from ringing in Britain shows most movements within 10 km, and that 95% of females are recovered within 36 km of their place of ringing and same number of males within 20 km, exceptions being midwinter movements across North Sea to Netherlands and Lithuania. In irruption years, flocks usually totalling up to 2,000 individuals, mostly of first-year birds from northern populations (where winter daylight too short to find food), move south and west in September and October to the Baltic region (30% of recoveries from Moscow region within 100 km southwest of ringing site), Netherlands, Britain and Ireland; some travel further, as much as 1,700‒2,700 km, to as far south as the Balkans, the upper reaches of River Danube, Switzerland and northeast Italy; included in such movements are birds from Russia recovered in Germany, Netherlands and Britain, and in extreme cases individuals from Kaliningrad (western Russia) reaching southern Ireland and southwest France. In northwest Russia in vicinity of large cities, most first-years and adults are resident; mostly resident also in Latvia, but in Lithuania more migratory, with recoveries in southern France and Portugal; similarly, many first-years from west Siberia recovered south of breeding range in Kazakhstan. Return movements to breeding areas occur in February–March, but in eruption or invasion years individuals may remain to breed in areas occupied during the winter (spread of range into north Norway resulted from winter invasions). In Vladivostok region of southeast Russia, some resident but majority depart from breeding areas in September‒October and return March‒April.