Migration reaches a peak in September when huge numbers of adult and young birds pass into, out of, over and through the country. The Park is not a notable stop-over place for migrants, common or otherwise; its size for one matter means that migrants can turn up almost anywhere undetected. There are, however, a few “hot-spots”: the enclosures by Conduit Wood; the high ground behind Holly Lodge and the Pen Ponds. It was at the latter where two unusual migrants, for the Park at least, were found on two early mornings. A Dunlin and a Greenshank, two species of wading or shore bird, found the fringe of mud around the Pen Ponds a useful place to feed and rest, at least until they were disturbed by visitors. Maybe more of these kinds of birds would be seen at the Pen Ponds if there was a stretch of undisturbed shoreline. The Dunlin was only the 7th record for the Park, the previous being 22 years ago.
The other highlight of the month was the unprecedented number of 19 Buzzards seen one late afternoon. A handful of birds are usually noticed silently making their way over the Park each year, many more doubtless pass high overhead undetected: but not so on the 19th. Alerted by Buzzard flocks seen elsewhere in west London, two local birders stationed themselves at either end of the Park and scoured the skies. For an hour very little happened until a group of four birds was sighted soaring high over Roehampton Gate. Further birds were seen including two low flyers, each noisily attended by mobbing Crows and Parakeets. Forty minutes later the passage peaked with a spectacular 'kettle' of a dozen birds circling over Sawyer's Hill, before drifting westwards. Several more birds were seen on subsequent days.
Another bird of prey became more frequent in the Park from mid-month. Hobbies were seen on several dates including one hunting bats over the Pen Ponds one evening. Swallows, House and Sand Martins streamed southwards with several sizeable flocks noted while scanning for raptors. Warblers continued their migration with Chiffchaff becoming the dominant species with up to eight birds being seen, usually with roving flocks of Tits. Three Sedge Warblers, a couple Lesser Whitethroats and a Garden Warbler were also noted. Of the chats, Wheatears and Whinchats continued their brief stop-overs, with another peak of three of the latter on the 12th. The first Stonechat of the autumn arrived on the 17th, Meadow Pipits increased to c.75 on the 21st and two scarce Yellow Wagtails flew over on the 5th.
Next month will see the arrival of winter visitors and increasing numbers of diurnal (day-flying) migrants passing over the Park. A postscript to last month's notes, both Great Crested Grebes and Swallows in fact raised four young each.
Jan Wilczur, September 2009