User:Chidgk1/sandbox2

Birds
The impact of wind energy on birds, which can fly into turbines, or have their habitats degraded by wind development, is complex. Displacement is thought to be more of a threat to species than collisions. Habitat loss is highly variable between species.

Hundreds of thousands of birds, including raptors and migrants,  are killed each year because of wind turbines and their power lines, but this is less than the number killed (or not born) because of fossil fuel (coal and gas) power stations. Wind farms are estimated to be responsible for losing less than 0.4 birds per gigawatt-hour (GWh) of electricity generated, compared to over 5 birds per GWh for fossil fueled power stations. As well as threatening extinction, one of the effects of climate change is to already cause a decline in bird population, and this is the main cause of bird loss from fossil power.

Turbines are banned on some important migration routes and birds may alter their flight paths to avoid them. Biological surveys beforehand and correctly siting turbines is very important, especially for raptors as they are slow to breed. Methods to help birds avoid turbines include painting of one of the turbine blades black, and making ultrasonic noise. Some approaching birds can be spotted, for example by avian radar, in time for turbines to be slowed to a speed which is safe for them. Wind farms may need more power lines, and lines may be made less damaging to compensate. Making permits for the number of birds (such as eagles) killed tradeable has been suggested, in order to save the most birds at the least cost.