Bird watchers get nervous when they see wind turbines (风力涡轮机) are never a rare sight nationwide. When the wind gets going, their blades can turn around at over 200km per hour. It is easy to imagine careless birds getting cut to bits. Campaigners often point to the possibility when trying to stop the building of new wind farms.
No one doubts that wind turbines do indeed kill at least some birds. But a new analysis of American data, published in Environmental Science & Technology, suggests the numbers are very small, and have little impact on bird population.
Wind power has expanded dramatically in America over the past 20 years. Many studies have analysed the effects in specific locations or on specific bird species. But few have looked at the effects on wildlife at the population level. Dr. Erik Katovich, an economist at the University of Geneva, made use of the Christmas Bird Count, a citizen- science project run by the National Audubon Society, an American non-profit organization. Volunteers count birds they spot over Christmas, and the society brings together the numbers and has kept the records for about a century.
Dr. Katovich assumed reasonably that if wind turbines harmed bird population, then the numbers seen in the Christmas Bird Count would drop in places where new turbines had been built. He combined bird population and species maps with the locations and construction dates of all wind turbines in the United States between 2000 and 2020. He found that building turbines had no noticeable effect on bird population. That finding held true even when he looked specifically at large birds like hawks, and eagles that many people believe are particularly likely to be struck.
"Wind power not only produces much less planet-heating carbon dioxide and methane than fossil fuels. It appears to be far less damaging to wildlife, too. Yet that is not the impression you would get from reading the news," said Dr. Katovich, "In 2020 alone, there were 173 stories in major American news agencies reporting the negative effects that wind turbines had on birds. The fact is, wind turbines might look dramatic. But their effect on birds is not."
