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| 17 06 12 http://lbcarchive.co.uk/forum/viewtopic.php?f=3&t=17067 |
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| Author: | John Walker [ Mon Jun 18, 2012 6:50 am ] |
| Post subject: | 17 06 12 |
3 flocks of juv starlings c 1000 in total along sea bank and saltmarsh Horseshoe point to Grainthorpe, and 2 pairs grey partridge. regards John |
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| Author: | Stuart Britton [ Mon Jun 18, 2012 2:01 pm ] |
| Post subject: | Re: 17 06 12 |
Is it common to just have juveniles in these large flocks - any ideas on the wehereabouts of the adults? |
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| Author: | Stuart Britton [ Thu Jun 21, 2012 9:07 am ] |
| Post subject: | Re: 17 06 12 |
Can any regular coast watcher help re my query? |
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| Author: | Graham Catley [ Thu Jun 21, 2012 9:27 am ] |
| Post subject: | Re: 17 06 12 |
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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| Author: | Kev Wilson [ Thu Jun 21, 2012 10:36 am ] |
| Post subject: | Re: 17 06 12 |
Unfortunately, no comprehensive counts of starlings at Gib since the recent influx began - clearly a large throughput of birds with flocks of up to 300 moving south and small numbers apparentoly coming in off the sea too. With the recruitment of so many juvs evident in these big annual summer flocks, it does make you ponder how this species is in trouble ! From a small sample that I have seen, I would estimate less that 5% adults. This mornong was my chance to get out and look but the coincidence of moderate rain and time off recently is not funny ! Cheers Kev |
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| Author: | Stuart Britton [ Thu Jun 21, 2012 6:49 pm ] |
| Post subject: | Re: 17 06 12 |
Thank you Graham for your comprehensive reply and Kevin for your observations. I think we take Starlings for granted but they obviously have a very complex post juvenile dispersal throughout Europe. |
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