Saturday 27 September 2008

27 SEPTEMBER 2008 - VISIBLE MIGRATION OVER IVINGHOE HILLS WHILST EVERYWHERE ELSE WAS FOGBOUND





















TODAY'S IMAGES
The view across the Chiltern Hills this morning showing the extent of the fog and the clear summit of Ivinghoe Hills (Dave Bilcock)
Three FIRECRESTS were present with a mobile Goldcrest flock (Bob Duckhouse/Dave Hutton)
Large numbers of Goldfinches remain, with an influx of both Jays and Song Thrushes (Mike Lawrence)
SATURDAY 27 SEPTEMBER 2008

At 0800 hours, birding in the vicinity of Amersham was out of the question, as dense fog was covering the entire region. Likewise, the Aylesbury Vale and Tring Area were equally out of bounds, so it was with some surprise to hear Dave Bilcock inform me of a Grey Plover that Mike Wallen had seen fly over Ivinghoe Beacon at 0720 hours. However, on speaking direct to Dave, I was amazed to hear that the very tip of the Beacon and the Top Scrub was completely clear......and more to the point, full of migrants.

I immediately made my way up and arrived shortly prior to 0900 hours.

IVINGHOE HILLS NR (0900-1100 hours)
(Dave Bilcock and Mike Wallen were both present, whilst I spent some time birding with Steve Rodwell)

Although clusters of dense fog drifted in and out during the period I was present, the Beacon, Top Scrub and upper slope of Steps Hill were largely clear, with blue skies and warm sunshine. Vismig was quite impressive, and amongst the highlights were 8 migrant Coal Tits, 3 Firecrests, large numbers of Song Thrushes and a large throng of mobile Jays.

For the first half hour, at least 107 HOUSE MARTINS graced the summit, commuting between the clear Beacon (where many were resting on the wires and perching on Hawthorns) and the scrubby area opposite the main car park. Some 25 BARN SWALLOWS were also associating with them.

In the tall Beech trees that border the road and the scrub between the car park and Steps Hill, a total of 8 different 'migrant' COAL TITS were encountered, at least two of which had bluish-grey upperparts and a striking white nape patch indicative of the migrant continental nominate form 'ater'.

Further migrants included 25 Goldcrest, amongst which were 3 FIRECRESTS, all actively moving along the line of mist on the upper reaches of Steps Hill (DB had also seen a single FIRECREST in scrub opposite the car park), as well as at least 17 BLACKCAPS and a single LESSER WHITETHROAT.

Equally impressive were the number of JAYS and CONTINENTAL SONG THRUSHES present. There were at least 27 of the former, with a tight flock of 12 birds constantly circling high above the scrub and attempting to fly out into the fog. After every attempt, they returned to the Top Scrub. Song Thrushes seemed everywhere, with their 'ticking' coming from every other Hawthorn bush as they flew out of cover. Numbers were difficult to estimate, but involved at least 30 birds.

MW and DB had also earlier recorded TREE PIPIT (4 flyovers) and REDWING (5 birds), whilst MW had seen a GREY PLOVER fly west at 0720 hours.

More resident 'fare' included 88 Goldfinch, 2+ Bullfinch, 2 MARSH TITS, 3 Common Treecreepers and Linnet, with 2 Magpies overhead, Skylark passage totalling 12 birds, Meadow Pipits 23 and Chaffinches 25. Three Mistle Thrush were also noted.

Woodpigeon 'vizmig' included 9 at 0948 (flying high SW), with 4 SISKINS.

There was much butterfly activity in the sunshine, with large numbers of Speckled Woods seen, and a few Red Admirals.

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