Sunday, 27 March 2011

Rare visitor amid the throng

Each morning, the Siskin flock announces its arrival at the garden feeding station with a cacophony of twittering calls. Perched at the top of the neighbouring sycamore, the Siskins will soon drop down through the branches to the feeders below. Despite the busy appearance of the flock itself, the birds are initially reluctant to move from the security of their lofty position. Perhaps the uncertainty stems from this tiny urban garden being so different to the acres of conifers and riverside alders that these birds will have been using over previous weeks.

Siskins are winter visitors for most of us, moving into gardens from February or March once the crops of wild seed are depleted. Many will have come from breeding grounds further north but some, notably in the west of the county, may be local breeders from Thetford Forest. The arrival of the Siskins is predictable, even if their numbers are not, but this year they have been joined by unusually large numbers of redpolls, which intermingle with their more common cousins. Redpolls are small finches, generally off-white and grey in appearance, with a prominent red forehead and soft brown nape and back. When seen alongside other visiting birds, they are fairly obvious.

Our redpoll was thought to be a subspecies of the Common Redpoll until fairly recently, subtly different in plumage, voice and behaviour. However, during the 1990s it was discovered that our redpoll is actually a different species and, having been elevated to full species status, it was given the name of Lesser Redpoll. Understandably, with many of the bird books on our shelves pre-dating the ‘discovery’ of this new species, there is still a fair bit of confusion among more casual birdwatchers, not least because the Common Redpoll is no longer the common species here! Having said this, Common Redpolls do turn up in Britain but always in much smaller numbers; their breeding grounds are positioned well to the north and east of us, stretching across the birch forests of northern Europe.

This winter has seen both increased numbers of Lesser Redpolls at garden feeders and an unusually large number of Common Redpolls in the country. With the former fairly regular in the Siskins flocks doing the rounds of Thetford’s feeding stations it is perhaps not surprising that there has been the odd Common Redpoll tagging along as well. Several have been caught and ringed by BTO staff at the various feeding stations operated throughout the Brecks and I was amazed to see one here in the centre of town. A neighbour, and fellow bird ringer, had caught it in his garden, a wonderful thing to see and something that made my week!

No comments:

Post a Comment