When it comes to disrupting the winter nesting of farmland birds, wind turbines don't appear to ruffle too many feathers. Researchers have found that the energy-generating machines caused only 1 out of 23 species studied to change its behavior. That's welcome news for both environmentalists and wind-energy companies looking to produce environmentally friendly power at low cost to local ecology.
The European Union recently set a goal for 20% of Europe's energy supply to come from renewable sources by 2020. A substantial amount of that energy will likely come from onshore and offshore wind farms. So far, most wind-energy companies have focused their efforts on building offshore wind turbines, and consequently most studies into the environmental effects of wind turbines have looked at their effects on coastal bird populations. These studies have shown that offshore wind farms are largely safe for migrating birds. But a few have studied the impact of wind farms in onshore environments, such as farmlands and moorlands. More and more European energy companies are looking to windswept lowlands for potential development, says Mark Whittingham, an ecologist at Newcastle University in the U.K., who decided to find out whether wind turbines on farmlands might displace local bird populations.
Whittingham and his colleagues surveyed birds near two wind farms in East Anglia, an eastern peninsula of England. They canvassed the farmlands and plotted the individual birds they encountered over 2 months in the winter of 2007. In total, the team recorded nearly 3000 birds from 23 different species, including five of high concern to conservationists: the yellowhammer, the Eurasian tree sparrow, the corn bunting, the Eurasian skylark, and the common reed bunting. Whittingham then analyzed the distribution of these birds at various distances from the turbines to almost a kilometer. He found that only one species, the common pheasant, seemed to nest farther away from the turbines--a nonissue, Whittingham says, because pheasants can easily adapt to new locations. The rest paid them no heed. The turbines, it turned out, don't seem to disrupt the birds' choice of grazing and nesting locations, the team reports this week in the Journal of Applied Ecology.
That suggests to Whittingham that farmlands might make suitable real estate for future wind-farm developers, although more research is needed to examine potential effects. For one, he says, the timing of his study might matter. Birds' winter behavior might differ from their behavior at other times of the year. Also, his team didn't look at how many birds are killed by the turbines themselves, Whittingham says, but he thinks that it's unlikely to be a significant number. Farmland birds, he says, are typically relatively small and can easily maneuver around turbines. (Turbine blades are much more dangerous for bats, though. See ScienceNOW, 25 August).
John Quinn, a zoologist at Oxford University in the U.K. who studies bird behavior, says the study "seems like a solid piece of work--the results are pretty convincing." But he echoes Whittingham's concerns about the study's limitations. A number of factors besides raw population distribution should be considered for future research, Quinn says. For instance, turbines might displace younger birds because they aren't as accustomed to the turbines, which could have implications for their future nesting choices. "You'd also want to be careful drawing conclusions to other habitats" and species, he says.