Sunday, 4 March 2007

Happy returns

It is wonderful to have the house sparrows back. There was a period of nearly two years when our local house sparrows ceased to visit the garden and the hanging feeders stuffed with tempting food. I am sure that it was the removal of the tall bushes next door that stimulated their disappearance. House sparrows like to feed from cover and they would raid from over the fence, retreating into the bushes if they felt threatened. Now that the new owners next door have reinstated the bushes, the house sparrows have made a welcome return. Bushes also serve another important purpose in sparrow society, providing a venue for the noisy communal gatherings that were once a common feature in our towns and cities. Such gatherings may well have an important social function, perhaps helping to maintain the colonial structure of house sparrow populations.

While the loss of our sparrows was a temporary one, it did mirror a widespread and longer-lasting phenomenon. House sparrow populations have declined across much of the country, the UK breeding population virtually halving in a little over two decades. Worrying though such a decline is, the house sparrow has not faired as badly as its county cousin, the tree sparrow. This now rather scarce bird has suffered from the loss of over-winter stubbles and other changes in farming practices, with a population decline of nearly 80% documented since the 1970s. Such changes stem from the demands that we, as consumers, place on the farming industry.

The two species are fairly easy to tell apart; the male house sparrow with his grey crown, white cheeks and black chinstrap, the latter extending down onto the chest in the form of a black bib. Female house sparrows (and young birds of both sexes) are a light sandy brown in colour with brown and grey streaks on the back and the wings. In tree sparrows the two sexes look identical and can be distinguished from house sparrows by the warm red-brown crown and the black spot that sits within the white cheek patch. There is also a narrow white collar and the black bib is smaller than that seen in the house sparrow. The two species are granivores, feeding on large seeds including cereal grains, and both share the relative large bill that is a feature of such seed-eaters. These immediately distinguish them from another small brown bird that is sometimes, quite wrongly, regarded as a sparrow. This is the dunnock, known by some as the hedge sparrow, a completely unrelated insectivorous species. While the sparrows are happy to feed from our hanging feeders, the solitary dunnock creeps about on the ground below, moving in a mouse-like fashion.

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