Wednesday, 6 July 2011

The First Session in the Reedbed for the Year

The two sessions at Leith Hill (one morning and one evening) produced another 37 new Siskin including just two adults.  I have been measuring every juvenile Siskin I have caught (103) and there has been a real variation in the blotch size of between 18mm and completely dark tails.  Going on the paper by 'Marine and Copete' 53 would be male (below 28mm), 47 female (above 29mm) and three intermediates at 28mm or 29mm.  There are also definite peaks around 21/24mm (32), 32/33mm (21) and completely dark tails account for 12 individuals.  Also, a few of the juveniles are starting to moult and five were clearly males (below) which helped to see how reliable measuring the tail blotches are for sexing.  These five birds had blotches of 18, 19, 20, 22 and 25mm - all within the male range.

Nests this week have involved two Pied Wagtails (five chicks in each), the Whitethroat nest from a few weeks ago was ready (three chicks and two eggs - below top), one Robin (three chicks) and one Wren (five chicks).  Whilst a visit to another Barn Owl box at Leith Hill produced a new adult male and a Pheasant was found sat on eggs (below bottom).

This week also included my first visit to the reedbed at Warnham LNR where in three hours I managed to catch 60 new birds of ten species including six Robin, seven Chiffchaff, 14 Blackcap, 15 Reed Warbler (below top), a Reed Bunting and a real surprise was a Greenfinch!  Whilst the highlights of the already ringed included an adult male Great Tit ringed here on 18th Oct 2006 as an immature, a control 2nd year female Reed Bunting (below bottom) which was ringed 8km away in Capel, Surrey on 30th December 2010 and a control Reed Warbler (L400228) which I am yet to get details of.  Amazingly these are only the second and third controls caught at this well worked site since at least 2000!  The other one being an immature Blue Tit (V945935) caught on 23rd November 2009 which I have yet to find its origin!  Does anyone recognise these two?

Birds ringed:
Pied Wagtail - 10 nestlings
Robin - 7 + 3 nestlings
Siskin - 37
Whitethroat - 1 + 3 nestlings
Coal Tit - 1
Great Tit - 16
Blackcap - 15
Dunnock - 3
Reed Warbler - 15
Blue Tit - 7
Reed Bunting - 1
Chaffinch - 2
Wren - 5 + 5 nestlings
Chiffchaff - 7
Greenfinch - 1
Blackbird - 1
Barn Owl - 1

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