Rare Bird Alert weekly round-up: 01 - 07 August 2012

The weeks highlights
Black-winged Pratincole on Lewis
Stilt Sandpiper in Northumberland
Feast of Great and Cory’s Shearwaters
Alpine Swift pleases the crowds in Norfolk

Weather-wise, the week was dominated by a slow-moving low pressure area to the west of Ireland. It remained almost anchored there from 1st to 3rd, feeding west or southwest winds into southern Ireland and southwest England. By 5th, however, it had moved across Britain and weakened before moving out into the North Sea. For most, the week was one of warm temperatures, only light to moderate winds and a succession of sometimes torrential showers. Despite the presence of a continental anticyclone to the east, it remained too distant to exert any influence and winds remained in the west throughout.

Headline birds
The star bird this week was a Black-winged Pratincole found in the early afternoon of 2nd at Loch Stiapabhat, just south of the Butt of Lewis, Western Isles. It then remained to 6th. Pratincoles are strange birds, combining features of both waders and terns, but their overall appearance still manages to be highly pleasing, particularly on the wing, and this must have been a fine sight hawking along the edge of the loch and consorting with Lapwings and Golden Plovers.

August is a good time for this species but the location is not a typical one. It illustrates once again the vagrant-producing potential of these furthest-flung outposts, both Shetland and the Western Isles acting as huge ‘heligoland traps’ for lost birds with, to stretch the analogy, their extremities acting as efficient ‘catching boxes’.

The next rare bird highlight of the week was a fine adult Stilt Sandpiper at Low Newton-by-the-Sea, Northumberland on 5th. Found in the evening, it was still present on 7th. This is still a very rare bird, with only 28 recorded in Britain to the end of 2010. Even better for those resident nearby, it was the first for Northumberland.

Meanwhile, despite the winds being only moderate in strength, the headlines were well and truly grabbed by a terrific movement of large shearwaters off southwest Ireland and then, on a smaller scale, off southwest England. After a handful of birds at the end of last week, events this week began with 4 Great Shearwaters off Galley Head, Cork on 1st and another off Old Head of Kinsale, also Cork, followed by larger numbers on 2nd, most notably 38 off Galley Head. On 3rd largest counts were 90 past Galley Head and 70 past Old Head of Kinsale. Fewer were seen away from Ireland though 5 were off Scilly on 2nd, 22 off Porthgwarra, Cornwall on 3rd with another off Orcombe Point, Devon and on 4th another 2 off Porthgwarra with other singles off Start Point and Berry Head, both Devon. Finally, 3 more passed Porthgwarra on 7th.

Cory’s Shearwaters were on the move too, with larger numbers of this species recorded. On 2nd 103 passed Ram Head and 150 passed Helvick Head, both Waterford, but larger numbers were off Cork - 277 off Cape Clear, 334 off Ballycotton and at least 1,000 off Galley Head. Counts remained almost as high on 3rd with 464 off Galley Head, 322 off Cape Clear and 267 off Seven Heads the largest numbers recorded. Away from Ireland, 11 were off Scilly on 2nd but, as with the Greats, sightings soon followed from the English mainland. The first was off Porthgwarra, Cornwall on 1st but 115 passed there on 3rd, on which date there were also 120 past St.Agnes, Scilly, in a single hour, 30 off St. Mary’s, Scilly and a single off Mousehole, Cornwall. Fifteen were off Porthgwarra on 4th and singles penetrated as far east as Prawle Point, Devon on 4th and Abbotsbury, Dorset on 5th. Another was off Porthgwarra on 7th.

These regular though erratic and unpredictable events in Ireland and the Southwest are exciting but such experiences are sadly but a dream for most British seawatchers for whom a glimpse of just a single Cory’s or Great Shearwater would constitute a good day.

Alpine Swifts are not always headline grabbers but this week’s long-staying bird at Sheringham, Norfolk became a real crowd-pleaser, often favouring the prominent clifftop hill known as ‘Beeston Bump’. This is again a classic example of how birds are ‘funnelled’ by geography. Arriving overland from the south, this northeast corner of East Anglia represents a ‘dead end’. Faced with the open sea, birds must choose whether to turn west or east or whether to simply linger. Local geography is then important. With its (by Norfolk standards) hilly terrain with cliffs and buildings offering potential roosting opportunities and shelter from the wind, the stretch of coast from Sheringham to Cromer offers a perfect mini-environment for swifts. This is at least the eleventh Alpine Swift for the area (though the first in August), making it one of the most reliable locations in the country for this species. It was still present on 6th.

Much more in the full online round-up
Seawatching roundup with great photos
- Video of Stilt Sandpiper
- migrant waders
- Gull-billed Tern in Wales
- First passerines of autumn

Plus lots of great photos, analysis, and predictions for next week...