Thrush-bearing cloud
When I stepped out of the house at 07.00hrs the air was laden with moisture. The weather forecast was that of a nagging band of rain stretched across the south-east of England, and unlikely to clear until the afternoon - but it's proposed edge was tantalisingly close to Dorking (according to one satellite image that I had looked at.) So, instead of heading to Colley Hill as intended, I made my way to Box Hill, hoping that the extra few miles west might make a difference in the weather.
Arriving at Box Hill made clear that it hadn't. The roads were awash with standing water, although the headlights did pick out a few Song Thrushes having a bathe. The hill top was shrouded in mist, but walking a third of the way down the scarp allowed some semblance of visibility across Dorking and on towards the Greensand Ridge. Looking south-east I could also just about see aircraft taking off and landing at Gatwick Airport, so I was ready for action. The only problem was the persistence in the drizzle, enough to be a nuisance. This was solved by finding an isolated Yew tree on the slope which I commandeered as an umbrella - this spot gave surprisingly good views from east all the way round to south-west.
The first hour chugged along with a modest number of Redwings and Chaffinches, enlivened by a few Fieldfare and single Siskin and Brambling. With little changing in the weather it was a bit of a surprise to be suddenly hit by some large thrush flocks, mostly following the scarp-line but some coming along the River Mole. The low cloud had kept them to the south of the scarp, as the higher ground was hidden from view. This allowed me excellent observation, as many of them passed directly over my head. Until 10.30hrs these two streams kept going, with Redwings outnumbering Fieldfares three to one. Flocks were generally pure of species, although the odd mixed flock did pass south-westwards. Most of the thrushes moving were in sizeable flocks, 25-75 the average size, the largest being 250.
As the drizzle abated I ventured down the slope and further to the west by 100m. And it was here that I found what I believe to be the best spot on the hill to observe visible migration. I had a good view along the scarp (both east and west), along the river and across the mouth of the Mole Gap. I was able to watch thrushes arrive from all of these directions. At this point, no doubt due to the cloud lifting a bit, a number of birds started to appear high above the mouth of the gap, having, I assumed, arrived along the crest of the downs from the east (I would have been hidden from these birds when I was standing underneath the Yew, but as the cloud was so low then I doubt that I missed any.) A number of flocks started to pitch down at this junction, landing in a small area of Yew and Beech. All 500 or so left together after only a few minutes rest, flying out over the gap, circling high. I watched them split up, with half of them crossing to the Denbigh's scarp, the others bearing west to north-west (Norbury Park area). Very few birds called all morning.
By 11.45hrs it seemed to stop, with a short burst again at 12.15hrs. An hour later I packed up myself.
There was one highlight just before I left though. I picked up a flock of eight Ring Ouzel flying along the scarp underneath me, their long-winged sleek shapes at once alerting me. All seemed to be young birds or adult females, not an adult male among them.
Final totals of the big two movers were 2760 Redwing and 804 Fieldfare. Mostly south-west.
Arriving at Box Hill made clear that it hadn't. The roads were awash with standing water, although the headlights did pick out a few Song Thrushes having a bathe. The hill top was shrouded in mist, but walking a third of the way down the scarp allowed some semblance of visibility across Dorking and on towards the Greensand Ridge. Looking south-east I could also just about see aircraft taking off and landing at Gatwick Airport, so I was ready for action. The only problem was the persistence in the drizzle, enough to be a nuisance. This was solved by finding an isolated Yew tree on the slope which I commandeered as an umbrella - this spot gave surprisingly good views from east all the way round to south-west.
The first hour chugged along with a modest number of Redwings and Chaffinches, enlivened by a few Fieldfare and single Siskin and Brambling. With little changing in the weather it was a bit of a surprise to be suddenly hit by some large thrush flocks, mostly following the scarp-line but some coming along the River Mole. The low cloud had kept them to the south of the scarp, as the higher ground was hidden from view. This allowed me excellent observation, as many of them passed directly over my head. Until 10.30hrs these two streams kept going, with Redwings outnumbering Fieldfares three to one. Flocks were generally pure of species, although the odd mixed flock did pass south-westwards. Most of the thrushes moving were in sizeable flocks, 25-75 the average size, the largest being 250.
As the drizzle abated I ventured down the slope and further to the west by 100m. And it was here that I found what I believe to be the best spot on the hill to observe visible migration. I had a good view along the scarp (both east and west), along the river and across the mouth of the Mole Gap. I was able to watch thrushes arrive from all of these directions. At this point, no doubt due to the cloud lifting a bit, a number of birds started to appear high above the mouth of the gap, having, I assumed, arrived along the crest of the downs from the east (I would have been hidden from these birds when I was standing underneath the Yew, but as the cloud was so low then I doubt that I missed any.) A number of flocks started to pitch down at this junction, landing in a small area of Yew and Beech. All 500 or so left together after only a few minutes rest, flying out over the gap, circling high. I watched them split up, with half of them crossing to the Denbigh's scarp, the others bearing west to north-west (Norbury Park area). Very few birds called all morning.
By 11.45hrs it seemed to stop, with a short burst again at 12.15hrs. An hour later I packed up myself.
There was one highlight just before I left though. I picked up a flock of eight Ring Ouzel flying along the scarp underneath me, their long-winged sleek shapes at once alerting me. All seemed to be young birds or adult females, not an adult male among them.
Final totals of the big two movers were 2760 Redwing and 804 Fieldfare. Mostly south-west.
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| Flight-lines today: Orange (Mole Gap), Yellow (scarp), Purple (river). Optimum viewpoint marked by green circle |
Comments
Alastair - did you ever do any vismig when you lived in Hadlow? Wondering what the high ground in mid-Kent would be like.