Springwatch British Wildlife: Accompanies the BBC 2 TV series. Stephen Moss
Читать онлайн книгу.
occurs after a spell of rain, as the frost covers up their food supply beneath the bark of trees. Numbers often drop heavily following such weather, though within two or three years the population usually bounces back.
©Paul Hobson/FLPA
With its colourful plumage and striking black mask, the nuthatch is one of the easiest woodland birds to identify.
©Mike Lane/FLPA
©Jurgen & Christine Sohns/FLPA
The house sparrow and the dunnock are often ignored in favour of more colourful garden birds, but show some fascinating behaviour.
Three birds in Britain share the name ‘sparrow’, two of which are true sparrows: the house and the tree sparrows. The third, the so-called ‘hedge sparrow’, is now more properly known as the dunnock. A member of the accentor family, it is completely unrelated to the seed-eating sparrows. Despite the name change, however, many people still refer to this charming little bird as a hedge sparrow.
Of all the birds that are seen in our gardens, towns and cities, surely the most familiar is the house sparrow. Sparrows have almost certainly lived alongside human beings longer than any other species of wild bird. They have done so from early times for one simple reason: our ancestors grew grain, which the sparrows could steal for food. We soon got our own back: communal nests of house sparrows, in the walls and roofs of our homes, were regularly raided for eggs to supplement a meagre diet.
As they have lived alongside us for so long, we have tended to take house sparrows more or less for granted. Their appearance doesn’t do them any favours. They are the classic ‘little brown job’, though the male, at least, can claim to be a little more handsome than his mate, with his grey and brown cap and smart black bib. Female and juvenile house sparrows really are the archetypal small brown bird, with few distinctive markings, apart from a pale stripe running behind the eye.
In recent years, many of us have taken to giving sparrows a helping hand by putting up communal nest boxes. The house sparrow is a sociable bird, which prefers to nest in colonies, so a box with several entrance holes and chambers is likely to encourage them. And they need this help. In the past few decades, the sparrow has declined faster and more seriously than almost any other garden bird. This is despite the fact that we now feed wild birds much more than previous generations, which should help one so tied to human habitation as the house sparrow.
The reasons for its rapid decline are complex. It is almost certainly down to a combination of factors, each of which may affect different populations of sparrows, and other birds, at different stages of their lives. We know that changes in farming practices – especially the sowing of winter wheat in autumn, which removes the amount of seed left on the land in winter – have affected sparrows as well as finches and buntings, their close relatives.
The ‘yuppification’ of our towns and cities, with loft conversions and the general tidying-up of homes, has undoubtedly reduced the number of places available for sparrows to nest under the eaves of houses. But the biggest problem may be an unseen one. It is thought that the change from leaded to unleaded petrol may have introduced a chemical into the atmosphere of our cities that kills off the small caterpillars on which baby sparrows are fed during the first two or three days of life.
If anything, the house sparrow’s country cousin, the tree sparrow, has fared even worse during the past few decades. Populations as a whole have declined by almost 90 per cent, which means the species has disappeared from many places where it used to thrive. Along with other seed-eating farmland birds, such as the linnet and yellowhammer, it has undoubtedly been hit hard by modern farming methods, which reduce the amount of available food and places for the birds to nest.
If you are lucky enough to find a flock of tree sparrows, they will all appear to be males. That is because the sexes are similar. Both male and female are a shade smaller than the house sparrow, with an all-brown cap, a brighter overall plumage, and a distinct black spot just behind the ear.
The dunnock is superficially similar to a sparrow, but if you take a closer look, you will notice its more horizontal posture, slender bill, and neat, plum-and-chestnut-coloured plumage. Whereas sparrows are usually seen in flocks, the dunnock is a solitary bird, hopping about beneath the bird table and minding its own business. In spring, though, dunnocks are transformed into sexual predators. Both males and females are highly promiscuous, seeking out other partners, despite being paired up with their original mate.
©Roger Tidman/FLPA
The tree sparrow is one of our fastest-declining woodland and farmland birds.
©Derek Middleton/FLPA
©Mike Lane/FLPA
The grey wagtail tends to prefer more watery habitats than its cousin the pied wagtail.
If there’s a bird walking purposefully, if a little erratically, across your closely cropped lawn, picking up insects and pumping its tail up and down as it does so, there’s a pretty good chance it is a pied wagtail. The commonest of our three wagtail species, the pied is also the easiest to identify: no other British breeding bird has the combination of black and white plumage, slender shape and long tail.
Yet, despite its elegant appearance and endearing habits, the pied wagtail is often overlooked. Perhaps this is because it does not join the tits, finches and sparrows squabbling on the bird table or seed feeders.
Instead, it wanders quietly but efficiently around short grass or pavements, using its sharp bill to grab the tiniest insects and other invertebrates that hide away between blades of grass or paving stones – an ecological niche it appears to have taken for itself alone.
Male and female pied wagtails do have different plumages, though you may need a close look to be of which one you are looking at. Males have a dark, almost black, back, and a black bib and throat contrasting with snow-white cheeks. The female also has white cheeks and a black bib, but her back is greyer. Youngsters have a less contrasting plumage, with a yellowish tinge to the head and face, giving them a rather dingy appearance, as if they forgot to wash.
The other two kinds of wagtail found in Britain are often confused with each other. Both have varying amounts of yellow in their plumage, but while one is, appropriately, called the yellow wagtail, the other, equally attractive bird is saddled with the rather misleading name of grey wagtail. So people often claim to have seen ‘yellow wagtails’ in the middle of winter, when this species has already migrated to Africa, and what they are actually seeing is a grey wagtail sporting a lemon-yellow plumage.
Confused? Well, the name ‘grey’ isn’t entirely wrong: grey wagtails do have a grey head and upper parts, while the yellow wagtail is olive-green above. Yellow wagtails are also much more yellow overall, with the colour extending from the face and throat all the way down the under parts, whereas the yellow on a grey wagtail is confined to the breast and belly. Female grey wagtails, and males in winter, have even less yellow on them: just a small patch underneath the tail.
The two differ in their chosen habitat as well. Grey wagtails are birds of fast-flowing rivers and streams. Like the dipper, they perch on rocks on the bank or in midstream, bobbing up and down before flying into the air to seize an unsuspecting fly. They usually build their nest in a small crack or crevice in the stone beneath a bridge. In winter, they will venture farther afield, sometimes turning up in unexpected places such as shopping-centre car parks, where, like their cousin the pied