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Stuart
I will try and look it up but if you have BWP have a check in there -- the June movements of flocks of mostly juv STarlings were a huge feature of days gone by when the British population was much higher; STarlings of course have synchronised breeding with all the juvs in an area hatching and fledging within a few days and hence the large flocks of juvs accompanied by adults forming on local playing fields and meadows in late May; the flocks appear to amalgamate and I guess that the local adults then tend to drop out of the flocks as June progresses but all of the flocks I have seen of late have held about 5% adults; on a very specific period around June 19th - 23rd there would always be a westerly passage of flocks of juveniles up the Humber that lasted for 2-3 days and could account for up to 5000 birds in a day -- whether these movements also went south down the coast I could be checked in past reports and I guess they may still be seen at Spurn (worth checking their web site)
1977 15000N at Saltfleetby June 19th
Barrow Haven 3500 west 20th 3250 west 21st
From BWPi
in summer, roosts larger with substantial segregation of adults and juveniles (Tahon et al. 1978);
Fledge at 19–22 days; rarely return to roost in own or another nest after fledging (C J Feare). Duration of family bonds after fledging not known with precision; rapidity with which some pairs re-nest after successful fledging of 1st brood suggests dependence on parents can only last a few days, but can be longer, especially with 2nd-brood young, some of which appear to stay with parents for 2–3 weeks (C J Feare).
Young disperse or, in some populations, undertake more extensive directional movements. Where resident, as in Britain, juveniles disperse after attaining independence from parents.
Juveniles of migratory populations undertake longer and more directional movements, as demonstrated in Switzerland (Studer-Thiersch 1969); juveniles in summer travel over 500 km north-west to Low Countries and northern France. From here begin autumn migration, initially mainly to Algeria, but during winter move west to Morocco and Iberia where many Swiss adults winter. Post-breeding movements of Polish juveniles also take them to Low Countries; although earlier than adults, this route nevertheless similar to that taken by adults (Gromadzki and Kania 1976). Young of 2nd broods tend to migrate shorter distance and winter closer to breeding area (Fliege 1984).
Where a summer migrant, among earliest bird species to return to breeding area. In Belgium (where partially migratory), arrival begins with older males in February, older females some days later and younger males and females as late as April–May (Verheyen 1969a); in Poland, migration begins February, peaks March (Gromadzki and Kania 1976); in southern Sweden, arrives late February to early March (Karlsson 1983); in southern and western Finland mid-March to mid-April (Korpimäki 1978); around Arkhangel'sk, arrives April (Dementiev and Gladkov 1954); further east, arrives later, in Kazakhstan 2nd half of March to late April (Sema 1978); in north-east of range in Perm' area (58°N) does not arrive until mid-April (Dementiev and Gladkov 1954).
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