How dangerous are magpies?
The magpie problem rouses passions and is difficult to answer satisfactorily. Magpies have been blamed for wiping out a neighbourhood's songbirds and causing the national decline of the song thrush. There is no doubt that magpies raid nests for eggs and nestlings. The question is whether this reduces the population, or whether the birds are still producing enough young to maintain the numbers of the adult population. The RSPB and other organisations have investigated the problem of magpies' affecting small bird populations and have failed to find any clear link. For instance, nationwide surveys of bird populations show there is no general link between rising magpie numbers and falling songbird numbers. With song thrushes and some other species, it has been found that they are still producing plenty of young. The decline is caused by increased mortality of adult birds in winter, presumably through shortage of food. This does not mean that magpies do not have an effect in some local situations. However, no one has done a controlled experiment of removing magpies, by trapping for instance, to see if other birds then increased. If it proved to be the case, we would then have the problem that control would have to be repeated when more magpies move in to fill the void. In suburban/village areas, we have provided ideal conditions for magpies: birdtables, abandoned burgers and other edible litter, and plenty of flattened carrion on roads, provide an abundance of food to maintain an artificially high population. One hopeful point is that it seems that magpies raid nests mostly when they have their own young to feed. As magpies nest early, second broods of smaller birds may be more successful. Early nests tend to be more vulnerable anyway because the vegetation has not grown up to provide cover. My garden is home to magpies, crows and jays, also sparrowhawks and cats, but I also have plenty of song thrushes, long-tailed tits and other small birds. Should feeding be continued in
summer? The received wisdom used to be that feeding birds in summer was a bad thing, partly because of the danger of nestlings choking on peanuts but also because it was felt that they ought to be receiving 'natural food'. When I argued otherwise, I had my wrists slapped, but summer feeding is now recommended by the RSPB and British Trust for Ornithology. The arguments are as follows. Ornithologists who examine hundreds of nests while ringing nestlings say that choking on nuts is extremely rare. The nestlings may be receiving nuts, scraps etc only because better food is not available, so the nuts may not be the prime cause of death. Gardens are short of natural bird food. They do not harbour so many insects as woods and hedgerows because pruning, weeding and mowing reduce the amount of foliage where insects live. And gardeners do not encourage caterpillars and aphids! This situation is made worse by bad weather: rain washes caterpillars from leaves and dry spells sends worms and snails under cover. Supplementary food can, therefore, be a positive boon for garden birds in summer. It may be most valuable when the young are just out of the nest. They need plenty of food but are still unskilled at finding it. There is evidence, including my own observations, that tits feed their young on insects but break off for a quick meal of nuts for themselves (treating the feeder as a fast food outlet for busy workers, so to speak.) So continue feeding through the year. To be on the safe side, make sure that the peanuts are provided in good quality feeders with strong wire mesh. This ensures that the birds cannot remove the nuts whole and have to chip out fragments. Is the bald bird in my garden
suffering from something nasty? In late summer, it is not unusual to see birds with heads and necks completely devoid of feathers. At one time my garden had a blackbird and a magpie with bald heads that made them look like ridiculous caricatures of tiny vultures. This is the time of year that many birds moult their feathers and baldness is a consequence of something going wrong with the normally orderly sequence of feather replacement. The moult is a time of stress for two reasons. The bird needs extra energy to grow new feathers, while at the same time, they use extra energy to fly and keep warm because of the gaps caused by shed feathers. A bald head creates an even greater stress because the brain is the one part of the body that must be kept warm at all costs. Without the insulating covering of feathers, there will be an enormous loss of heat from the head. The situation is made yet worse because the moult takes place after the nesting season when birds may be already in poor condition from the effort of rearing their families. Sometimes they are in such a feeble state that feather replacement has to slow down. The bird goes bald because the head is the last part of the body to moult and, under extreme conditions, the feathers, which have been weakened by fungi and other micro-organisms, are shed before the new feathers are ready. So everything is conspiring against these odd-looking birds, and they should be objects of pity rather than ridicule. Why have all the birds disappeared? This is often asked in the late summer months. After the bustle of the nesting season, the garden goes quiet. The newly fledged young, if they survive the first few weeks of independent life, are seeking a niche for themselves. Their parents are undergoing the moult (see above) which taxes their reserves and they spend their time quietly under cover. After a few weeks, they come out again and singing resumes in a sort of Indian summer. Why do birds strike/tap windows? My father was very interested in the problem of birds striking windows and corresponded with many people and visited some problem birds, but he never got to the bottom of the problem. The standard answer is that the window is in the bird’s territory and when it catches sight of its reflection mistakes it for a rival. This certainly seems to be the answer to some instances but it is not always so simple. The bird can be so obsessive that it attacks every window in a house, every day. And I have seen this behaviour in non-territorial females. This makes the cure more of a problem! You can try stringing enough strands of cotton to actually keep the bird away from the panes. According to the RSPB, the only way to prevent the attacks is to cover the glass with clear, non-reflecting plastic or, less effectively, hang a curtain of plastic strips that flutter in the breeze. This is not always practicable or desirable. So my rather negative answer is to hope that the bird goes away, dies or gives up! I rarely hear the final outcome from correspondents but, in my experience, the attacks eventually stop, presumably because the bird has died, gone away or lost interest. One consolation is that you are lucky not to suffer like one house my father visited. The daily attacks by their problem crow were so violent they left the windows covered in blood. What plants are worth growing to attract birds? When researching my book The Bird Garden, I browsed the pages of the massively huge and comprehensive volumes of The Birds of the Western Palearctic. It lists the foods eaten by every species and a very wide variety of plants are mentioned. Some plants appear to attract a wide variety of birds but this does not mean that a plant is commonly eaten by birds. Sometimes the listing referred to a single observation. I would grow only a few plants with the hope that they would significantly attract birds into the garden or contribute to their nutrition. But it is difficult to give a comprehensive list because there are local preferences: plants attacked avidly in one neighbourhood may be shunned in another. My suggestion is: I would grow other plants for their horticultural interest and be delighted if I found birds feeding on them.
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