A party of four EUROPEAN HONEY BUZZARDS drifted south over the Ivinghoe Hills escarpment today
TUESDAY 9 SEPTEMBER 2008
(A day of moderate SE winds, veering SW and freshening in the evening; dry during the morning but from midday onwards, heave rain set in and continued into early evening. Warm, with temperatures reaching 18 degrees centigrade)
WILSTONE RESERVOIR
(0910-0930 hours; water levels risen remarkably, so much so that only limited mud now available)
LITTLE EGRETS - 4 birds now present, 3 showing very well from Drayton Bank Hide
COMMON GREENSHANKS - 3 juveniles remaining
HOBBY - 1+
HOUSE MARTINS - 125+
*MEDITERRANEAN GULL - a first-winter flew over at 1925 (Steve Rodwell only)
*BLACK TERNS - 5 juveniles arrived at Startopsend Reservoir at 0823 hours, with 4 further birds shortly later; all then quickly relocated to Wilstone, where they all remained until at least 0900 (Steve Rodwell). All had disappeared by 0925, but 8 'new' moulting adults arrived late afternoon on Wilstone (Dave Bilcock/LGRE), At 1905 hours, they circled very high and disappeared into the clouds as they headed west towards Buckinghamshire (Steve Rodwell).
COMMON TERNS - 3 adults were present from 1815-1845 (SR)
Common Starlings - a feeding flock (mainly on Blackberry bushes) was by the roundabout NW of Startopsend Reservoir. The flock numbered at least 105 birds.
STARTOPSEND RESERVOIR
Northern Shoveler - 18
House Martins - 60+
SAND MARTIN - at least 10
IVINGHOE HILLS NATURE RESERVE
I moved up to Ivinghoe mid-morning in the hope of a flyover Tree Pipit or some migration in the light SE winds and intermittent cloud cover. I parked up in the main car park and sat down on the adjacent slope to 'scope the sheep pens. After scanning the fences to no avail, I panned around the far hills towards Dagnall and Whipsnade and in doing so, came across a small group of migrating raptors. My initial thought was of a family of local Common Buzzards but as they were very close together and two were extremely white on the underparts, I had immediate suspicions that they were not.
The group were flying very low over the Icknield Way footpath and as they drifted up over the far ridge (the ridge where the recent Short-eared Owl was last seen), they seemed to intermingle. They flew along the entire ridge towards me and at 350 yards east of the summit, I was able to confirm that they were a close-knit flock of EUROPEAN HONEY BUZZARDS. In fact the downcurved nature of their flight silhouette had already put me off Common Buzzard. They gradually flew closer and drifted very low along the eastern side of the hills, eventually passing me at 100 yards range as I sat on the hillside.
I had initially picked them up at 1016 hours, and it was not until 1023 that they were downslope of the car park. Once I had confirmed their identity, I attempted to alert other local birders, but because of serious 'phone problems at this site, I was only able to get hold of Peter at Rare Bird Alert. I shouted some 'pigeon english' direction down the phone and then tried to text the news to Dave Bilcock, Francis Buckle and others I knew were in the vicinity.
They kept low until they reached the far slope covered in hawthorn and they then drifted together upwards in a 'kettle'. They gained sufficient height to skirt the woodland and headed off strongly in the direction of Ringshall and Don Otter's cottage. In order to keep on them, I had to physically run down to the lower Icknield Way footpath and then attempt to follow them as they approached the Gade Valley and the escarpment south of Dagnall. Unfortunately, at the same time, my attentions were diverted to dealing with a Caspian Stonechat report (a potential 3rd for Britain) and then shortly later, a Spotted Crake at Dunstable Sewage Farm. Attempting to get a phone signal proved frustrating and in the end, I had to forsake the buzzards, and lost them as they headed quite rapidly towards a narrow window of sunshine and patchy cloud towards Hemel Hempstead at 1038 hours.
I eventually managed to talk direct to both JT and FB but by then, the birds had totally disappeared from my view and I could no longer give them specific directions on where to relocate them (FB had managed to position himself somewhere near Dagnall). In the meantime, Mike Collard had phoned, and he was able to relay information to the email groups. I guess the four birds entered Buckinghamshire, Hertfordshire and Bedfordshire airspace as they migrated south, but throughout much of my observation, they kept within Bucks.
DESCRIPTION
For several minutes, I obtained excellent views of the quartet, two birds being obvious pale morphs and the other two dark. It was clear that one bird was an adult male - he had a predominantly pale grey head with somewhat paler sides and was grey on the upperparts with distinct blackish bars on the upper tail and upperwings.The black trailing edge to the wings was broad and distinct, with black tips to the primaries and a noticeable broad band to the tail at the tip. The lower underparts were strongly barred, with a dark suffusion of brownish feathers towards the breast. In profile, he looked very small-bodied (and small-headed) with long wings. In fact, his wings were noticeably longer than the other three individuals accompanying him.
The other three birds were remarkably variable, with completely black outer primaries and noticeably darker secondaries, leading me to believe they were juveniles. One bird was very dark, being dark to medium brown on the entire underparts, on the underwing-coverts and on the head. It had strong contrast in the underwing, with blackish outer 'hand' and whitish, rather sparsely barred inner primaries. The tail was fairly dark also, making it difficult to discern the patterning of the tail bars.
Two individuals were pale morph, with the underparts predominantly whitish bar a few heavy streaks on the upper breast. However, the two birds were quite different individually, especially in the amount and positioning of the light streaking. The underwing coverts and axillaries were also very clean and pale, showing a considerable contrast between the blackish carpal-patch and the neatly barred flight feathers. Once again, the outer primary feathers were all dark (right down to the base), with the secondaries darker-based (the pattern was slightly reminiscent of the Ospreys of the previous day). The tail pattern was far more significant than on the dark juvenile, with three regularly spaced dark bars being apparent.
It was the characteristic shape and profile when in gliding flight that was most defining. Head-on over the slope, the silhouette was rather flat, with the wings of the male noticeably downcurved, or occasionally slightly upturned when thermalling upwards. As they took to more active flight across the downland, the flaps were high and cumbersome, and the small-head and long tail combination was unique. Often the flapping reminded me of Short-eared Owl and was much more labouring than Common Buzzard.
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