Altamont Pass may be an anomaly, but it is not the only threat to birds. The sagebrush plains of Wyoming and Montana have areas that are excellent for wind power but are also the habitat for the endangered sage grouse. The major problem for the sage grouse is not flying into the rotors but the very presence of the tall towers. The natural predators for sage grouse are raptors that like to perch on high structures to spy their dinner, so sage grouse instinctively avoid areas where wind turbines are installed. Wyoming has acted to put a voluntary sage grouse protec­tion plan in place by identifying core areas for sage grouse and restricting activi­ties in these areas. The areas were identified largely with the oil and gas industry in mind, however, not the wind industry. As a result, 23% of the class 4 or higher, and half of the class 6 and 7, winds are excluded from wind power development. This puts the oil and gas energy companies at odds with the wind energy com­panies, but oil and gas pay more of the state’s bills and have more clout (66). The outcome of this battle is uncertain but is emblematic of the problems that wind power faces.

Montana faces similar issues. The Nature Conservancy did a study to identify core areas for wind power that are relatively free of conflicts with sage grouse and other bird species (67). They estimate that of the 17 million acres of good to superb wind energy potential, about 7.7 million acres have a high potential for risks to breeding and resident bird species, including sage grouse, numerous grassland endemic species, piping plover and interior least tern, waterfowl, and bats. They concluded that Montana has about 9.2 million acres of land that could sustain wind power development without endangering native species.

So how many birds are killed by wind power? That is a difficult question to answer and the few studies are not very definitive. A National Academy of Sciences study of environmental effects of wind power (68) concluded that the average death rate for raptors is 0.03 per MW of rated power per year. At Altamont Pass, though, the rate for raptor kill is 1.94 per MW (69). But about 80% of birds killed are not raptors but passerines, mostly songbirds that are protected by the Migratory Bird Treaty Reform Act of 2005. The death rate varies widely between studies but most fall within the range of 2-4 birds killed per MW per year, though one study was as high as 12. With the current 50 GW of installed wind capacity, that would mean 100,000 to 200,000 birds killed per year and over half a million at the highest reported rate. The Fish and Wildlife Service (FWS) estimated in 2009 that 440,000 birds are killed by wind turbines each year (70). Of course, as wind power is scaled up, the number of birds killed would be expected to increase proportionally unless siting of wind farms is done to protect birds. Scaling up the FWS estimate to the DOE scenario of 20% of electricity in the United States from the wind would mean the possibility of over 3 million birds killed per year.

Bats are another issue for wind power. For reasons that are not entirely clear, bats seem to be killed at higher rates than birds. One hypothesis is that the tall white towers act as visual beacons to attract insects and bats. Another possibil­ity is that the audible and ultrasonic sounds of wind turbines may either attract bats or confuse their echolocation process (68). Bats are killed at high rates along forested ridge-top wind farms in the East, ranging from 15 to 41 bats killed per MW per year. Generally, the rates have been lower in the West and Midwest, ranging from 0.8 to 8.6 bats per MW per year, but a study in southwestern Alberta, Canada, showed high kill rates, similar to those of ridge-tops in the East (68). Bats are of particular concern because they are already threatened from the white nose syndrome that is killing millions of bats (71). Additional killing from wind turbines could be the straw that broke the bat’s back. A wind farm in Pennsylvania was shut down for a month and a half during the bat migration sea­son because a state — and federal-protected Indiana bat was killed. Another wind farm in West Virginia reached a court settlement that it could operate 24 hours a day from mid-November until April 1 when bats are hibernating. During the other months, the farm cannot operate at night (72). Bats are extremely impor­tant for both the vast quantity of insects they eat as well as the pollination they provide for many plants. It is very important to minimize bat killing from wind turbines.

But we need to keep this in perspective. According to the National Academy of Sciences report:

Collisions with buildings kill 97 to 976 million birds annually; collisions with high-tension lines kill at least 130 million birds, perhaps more than 1 billion; collisions with communications towers kill between 4 and 5 million based on “conservative estimates," but could be as high as 50 million; cars may kill 80 million birds per year; and collisions with wind turbines killed an estimated 20,000 to 37,000 birds per year in 2003, with all but 9,200 of those deaths occurring in California. Toxic chemicals, including pesticides, kill more than 72 million birds each year, while domestic cats are estimated to kill hundreds of millions of songbirds and other species each year. (68)

These numbers have a huge amount of uncertainty, but even so, it is clear that wind power is not going to be the major killer of birds. However, that does not mean that wind farm development should not take bird killing into account. Major flyways of migratory birds in Nebraska, Kansas, and the Texas panhandle are prime areas for wind power development. To avoid unnecessary killing of these birds, ecologically important areas need to be excluded from wind power development, following the approach used in Wyoming and Montana. The US Department of the Interior, in collaboration with environmental groups, recently issued guidelines on siting wind towers to assess and minimize their impacts on wildlife and their habitat, a good step in the right direction (73).

There are other environmental issues associated with wind power. The network of wide roads necessary to install the wind turbines and the trenches to bury the wires collecting the generated power disrupt natural areas, particularly in the northeastern mountains. Trees on ridgelines have to be cut down in an area of several acres around each tower so they don’t block the wind. These roads and cleared areas cause habitat fragmentation and increase the spread of invasive spe­cies. The net effect of these environmental insults is not clear, but they are clearly disruptive to some degree (68).

Humans react differently to the tall towers that are popping up like mushrooms throughout the country. Some people like them, or at least are not opposed to them, and some farmers and ranchers especially like the financial benefits that they get from leasing land for wind turbines. Wyoming ranchers can get $4,000 per MW per year for wind turbines on their property and more generally rates range from $4,000 to $6,000 per MW installed capacity (66, 74). But other peo­ple, including myself, have concerns about these huge industrial wind farms and associated transmission lines popping up in beautiful places. Mountain ridges are prime areas for wind turbines because of the high wind rating. To put wind tur­bines on mountain ridges or passes or undeveloped natural areas destroys the essence of what is most compelling about undisturbed nature—the sense of peace and tranquility and unity with nature that is a balm to the human soul.

I, for one, do not welcome wind turbines that destroy the viewshed in these places, and I am not alone. Colorado State University wanted to build a wind farm to generate up to 200 MW on a ranch it owns near the Colorado-Wyoming border. The project was met with vociferous opposition by the people living in the area who had unbroken views of the mountains but would now see wind tur­bines. Extensive wind farms are being proposed in Vermont, and there are many people opposed to them because of the environmental and visual effects (63). A proposed wind farm in the Flint Hills of Kansas was met with a lawsuit by the Flint Hills Tallgrass Prairie Heritage Foundation and the Audubon Society of Kansas because of danger to migratory birds and aesthetic views (75). In 2011 the governor of Kansas designated nearly 11,000 square miles of protected land in the Flint Hills that cannot have wind farms (76). For years there was opposition to the development of wind power off Cape Cod. A quick Google search on opposition to wind farms or solar power gets over 6 million hits for each. And so it goes.