Winter: brrrr.....

Saturday, 09 January 2010

My first entry for a while and how things have changed! The weather in the UK now dominates every news flash and conversation and, of course, thoughts about the effect of it on our wildlife. The temperatures haven’t been that low (and are currently forecast to rise) and certainly not as low as that experienced by the UK’s wildlife in similar weather in the early 1980’s. Nevertheless, with temperatures falling to minus 6.4 degrees Celsius at Farlington Marshes recently and daytime temperatures rising little above freezing this will undoubtedly have a significant effect on bird populations. But it’s not really (or just) low temperatures that are affecting the birds. The most significant feature and product of the current weather is the ice and snow cover. Many smaller water bodies are completely frozen over and larger ones almost so. The landscape is also at least ankle-deep in snow which is severely limiting the availability of open ground on which many species need to find food in order to survive. The knock-on effect of widespread snow cover was immediately evident last Wednesday (06 January) after a night and morning of almost continual snow across Britain: thrushes, larks, plovers and pipits were all on the move, despite the grim travelling conditions. Thrushes, especially refugee Redwings and Fieldfares, can now be seen almost anywhere with bare areas of ground (e.g. under hedgerows and trees) or berries (often on ornamental trees and shrubs in parks and gardens). Many Lapwings have left southwards (to France and Spain) and those that remain are mostly confined to the open mudflats and saltmarhes which so far haven’t frozen (at least locally). Skylarks and Woodlarks were also travelling in numbers but have now stopped. Hopefully they have all found a place to feed otherwise their future is bleak.

Farlington Marshes and the Langstone Harbour islands are snow-covered (just in case I didn’t make that clear!) and look like I have never seen the area before. The very wet and mild late autumn of last year now seems like a distant memory. All the ponds, lakes and ditches are frozen over, with open water confined almost entirely to the stream overlooked by the reserve’s information building. Most of the ducks and geese have abandoned the site and can now be found only in the harbour, with concentrations along the north shore (especially Broadmarsh and Southmoor).

At least two Pale-bellied Brent Geese are now in residence around the reserve, and several elsewhere in the harbour. They can be found with the large flocks of Dark-bellied Brent Geese but often take time to find. As their names suggest the most obvious differences between these two “forms” of Brent Geese relate to the tone of their bellies. Importantly, Pale-bellied Brents have the white of their vent extending between their legs and onto their bellies; Dark-bellied Brents are dark in this area. Also, the flanks of Pale-bellied Brents are conspicuously white and frosty; Dark-bellied Brents have smaller off-white flank patches contrasting less with the upperparts. Other subtle differences include: Pale-bellied Brents have browner upperparts whereas Dark-bellied Brents are greyer; Pale-bellied Brents rarely have much more than two small triangular white patches on each side of the neck, whereas Dark-bellied Brents are more variable and often have fuller and more extensive patches extending into the front of the neck. Just to give an example, here’s a short video clip I took a few weeks ago (after the December snowfall) at Farlington of one of the wintering Pale-bellied Brent Geese. The foreground Dark-bellied Brent Goose does provide a useful comparison even if it almost gets in the way!

The reedbed at The Marsh is half flattened by the weight of the snow and has left the Bearded Tits vulnerable to predation from birds of prey. I watched a hungry male Sparrowhawk hunting along the edge of the reeds yesterday which almost took one and persisted for a while looking for more chances as it perched on the open ice before finally giving up and flying off. I wasn’t quite quick enough with my camera and telescope setup to capture this on film, but in true “and here’s one I took earlier” style I did take some video clips of the Beardies feeding near the front edge of the lake a few weeks ago. This is still a good place to look for them, as up to 30 have gathered here to feast on the reed seeds which are clearly abundant this year. Reed Buntings can also been seen well in this area, also feeding on the reed seeds.

Bearded Tits can also be prone to predation from Marsh Harriers, and today one appeared in the area and roosted in the reedbed at Farlington. Earlier in the day it had been hunting over the harbour islands, where there were also two male Hen Harriers. The latter are rarities in the area mid-winter, and another attractive and spectacular species. Their pale grey ghost-like appearance as they quartered over the saltmarhes and islands was a delight to see. Their prey is mostly ground-dwelling birds (e.g. Skylark) and mammals. I would favour the former though. Other birds of prey today included the regular wintering Merlin which seems to live on North Binness and Long Islands, the huge adult female Peregrine, and several Common Buzzards, two of which have recently taken to hunting for Rabbits over the fields at Farlington.

Other scarce birds which have appeared during the last few days as a result of the weather include: a Bittern at Farlington yesterday which landed in the reedbed with prey early afternoon but left west at dusk; a group of four Red-crested Pochards on Thursday which spent much of the day in Bedhampton Creek before leaving east; and a drake Green-winged Teal at Budds Sewage Farm pools, found this morning, which will hopefully stay around a while like the last one at Farlington Marshes did in October/November 2008. Some definitely settled birds (not associated with the recent cold weather) include: two Long-tailed Ducks now in residence in the harbour south of Broadmarsh; up to 37 Avocets in the harbour just west of Farlington Marshes; and up to 20 Black-necked Grebes and three Slavonian Grebes in the main Langstone Channel off West Hayling Oysterbeds.

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