Some tits exploring the neighborhood feeders, others fly up to the window and look at me as if asking: when will finally be eating ?! I look at them and remorse because I do not believe that the food would be, or what they will get their favorite treats.
Recently, I wrote that the tits are able to sniff out the insects and thus help the trees, and along with the people who care about the fate of the plant. After this article, I received a lot of letters with questions of when and how to begin to feed the birds, and helps if such feeding insect control, which we consider pests. On the second question I will answer immediately. Where the birds are fed, they are becoming more – including insectivores, which include tit. They eat our treats, and at the same time actively combing the forest floor (if it is not covered with snow) and nearby trees, eating there wintering insects and their eggs. Of course, the best bird feeders clean neighborhood: the farther away, the more insects survive.
On issues related to feeding, there is, unfortunately, a serious problem. In light of the research results, which were published this year in the journal Nature, it turns out that it is better not to feed the birds. I know, I know, many of you are now stirred their hair: How’s that ?! Do not feed the birds in winter? Then, when they so need our help ?! Well, if we talk about aid, it has long been known that birds are not so much in need. All kinds of birds, of which we are now Feeding the without problems experienced thousands of years when winters were much more severe than it is now.
Feeding – the phenomenon is quite modern. It appeared when we humans began to produce more food than they could eat themselves. This is especially true of mass feeding of birds that can be observed today. I could not find data for Poland, but the figures that lead scientists in relation to other countries, show how a large-scale phenomenon we are dealing with. For example, in the United States in 2002 hit 450 million kilograms of grain in the trough, and in 2006 alone, the volume of the US market, associated with the dressing of birds, estimated at $ 4.5 billion. In the UK, where the birds are fed at 75% of individual households, in the year for that purpose spent about 300 million pounds. According to scientists, if we take the most popular forms of visiting local feeder (titmice, finches, thrushes, robins), then one has to only nine feeder birds. Is it good or bad? Of course, people (eg, such as I), which, thanks to the feeder can watch the birds and take pictures of them, like this activity, but scientists are increasingly vocal about him skeptically. It is not the first year indicate that the trough, where the birds are going to become a breeding ground for diseases. Called the simplest single-celled parasite trichomoniasis, which destroyed a lot of British linnets and finches, rapidly spread because of the feeder network.
But let us return to the study, which Nature wrote. The bad news even more. Scientists from the University of Exeter, the British Ornithological Foundation and their Italian colleague from Turin decided to find out what impact feeding birds has on their reproduction. In the center of the study was tit, blue tit – the most frequent visitor to our feeders. To study did not interfere with the external factors, especially other people, three populations tits were chosen for the experiment, found in the woods. Since (as is well known to every child) tits love fat, scientists have suggested this particular birds feed. One group received pure lard, the second – with the addition of vitamin E, as a third did not receive anything. Birds, especially such small as tit, can not be put off fat reserves. So theoretically the amount eaten should not influence their shape during the breeding season, which begins in a few weeks after the end of winter feedings. However, fine fat soluble different substances, including vitamins and antioxidants which remain in the body for a long time.
When the researchers compared the results of observations in three years, they in for a surprise. It turned out that much more successfully bred those tits who did not receive supplementary food: the yolk in their eggs were larger and the chicks leave the nest, were stronger and healthier. Indicators tits receiving the E vitamin, were slightly better than those receiving a simple fat, but the chicks in both groups significantly lagged behind those whose parents were left to themselves. How can this be explained? As a result, feeding disrupted natural selection, form a bird that would not survive the winter, or would be so weak as a result of a family that did not dare to start young. Feeding can also disturb the birds estimate future breeding territory: since there is food, it may seem appropriate to them, but do not be so in reality. And it is impossible to feed the chicks food from bird feeders, they need insects. Finally, a dressing may cause that a natural feathered refuse to consume food or her less. And it is more balanced and nutritious than food offered by the man – bird fast food, use of which can not affect the state of birds.