For some years we've been very worried about the decline in house sparrow numbers in Ormsaigbeg. Our concern was shared - the RSPB website here suggests there has been a steady fall in numbers over a long period, with a 71% drop between the years 1977 and 2008, to the extent that they are now red-listed as a species of high conservation concern.Red listed! Sparrows used to be as common as the dust they bathed in. One could hardly imagine a world without them. The idea that this noisy, quarrelsome, gregarious and cheeky little bird might disappear was too horrific to contemplate. Research was being done to discover the causes before there was a catastrophe.
Well, we're pleased to report that, whatever the trends elsewhere, our sparrows showed a sudden, amazing resurgence during the summer. It was getting to the point where they were becoming a nuisance again, and we'd have been quite pleased if the researchers had come and helped themselves to a few to take away for research purposes and to reintroduce them in places where they were needed.
During the breeding season, mothers and fathers were bringing their young along to our feeders and explaining how to out-compete the chaffinches which had, until then, been our main customers.
With the onset of winter things began to change again. The sparrows didn't disappear, but their numbers started to fall. Part of the trouble seemed to be that they were being buried under chaffinches.
Chaffinches are simply better at doing everything. They're supposed to be ground-feeding birds - the finches that turned over the chaff for seed that had been left after harvest - but now they're almost as good as the tits at hanging off windswept peanut feeders. For all their valiant efforts, the sparrows are simply being out-competed for food.
As the winter draws to an end, we only have a few sparrows coming in for food, but the important thing is that they have survived. Here's hoping that they have a good nesting season and become a nuisance once again.
In Achnaha, a significant factor in the decline in the number of sparrows between summer and autumn is the presence of a very active sparrowhawk. Like you we saw a good increase in sparrow numbers last summer, with many nesting over a period of several months, but the sparrowhawk was constantly present in the autumn, to the extent that we had to take the feeders down.
ReplyDeleteHere in rural East Yorkshire the sparrow numbers seem to be picking up a bit; it's lovely to hear a hedge full of bickering birds! Still not the numbers there used to be though.
DeleteWe had a theory that the decline in numbers coincided with the introduction of unleaded petrol; that shouldn't have made much difference in your area though.
Certainly chaffinches are competing much more; it has only been in the last few years that they have learned to feed from our garden feeders though.
Although one sparrowhawk could have a very localised effect, I'm surprised it would predate sparrows more than other garden birds; our local sparrowhawk is happy with anything up to the size of a collared dove.
Finally please forgive me if I end up posting two replies again; I'm having trouble with Google!
Sparrowhawks take sparrows as the name denotes. No surprises there then. Raptors are predators and as such will take small birds from human placed feeders which are really like a free MacDonalds for wee birds of prey. I would really welcome the visit of a sparrowhawk anytime at mine. Especially if they took the jackdaws which I find a bit of a pest here. Sparrow numbers are on the increase again in this area and I am sure predation has very little lasting effect on numbers. I really don't see any point in feeding in the summer and the breeding season anyway. I saw some nice tree sparrows at Caerlaverock yesterday and a peregrine and a nice wee male sparrowhawk.
ReplyDeleteI appreciate that where I live (the Carse of Gowrie, by Dundee) is very different agriculturally from Ardnamurchan, but although Sparrow numbers have dropped in suburban gardens here, their numbers increased in the villages along the Carse. Their numbers & location (i.e. garden bird feeders - or not) seems to depend very much on what crops are being grown in the fields.
DeleteAlan G