Altamont Wind Pass and Bird Mortality

Altamont Pass Wind Farm

And now for a drastic change in course…

(In case you’re wondering, yes, I skated. Sort of. I shuffled across the ice while wearing skates, and then I fell on my ass and bruised my tailbone so badly I could hardly walk the next day. Very graceful! But I will be skating again, and probably soon.)

The Altamont Pass Wind Farm, located in California and built during 1981 after the energy crisis, is a favourite plank of the anti-wind argument. Why? Because approximately 4,700 birds, 1,300 of them raptors,* die there every year. Therefore, anti-wind advocates claim, wind farms slaughter birds and industry claims that turbines kill on average one bird each per year are obviously lies.

No one disputes the avian death toll at Altamont. Thousands of birds die there every year.

But this leaves much out: the turbines are thirty years old; they were sited before environmental assessments changed the way major projects are constructed, and back then no one considered the impact on birds. Altamont Wind Pass is a major migratory route and population centre for many sensitive raptor species, including golden eagles.

But the most important, most overlooked fact?

Altamont Wind Farm has just under 4,500 turbines.**

Therefore, each turbine kills on average about one bird per year.

Now. An annual slaughter of 4,700 birds, even if it is a low number per turbine, is clearly not a good thing. No one wants to kill birds. (Except hunters, but I think they’d find this method rather unsatisfactory.) But whatever the pros and cons of Altamont may be, it is a lousy argument against modern wind farms, which require environmental assessments, avoid migratory routes and avian population centres, and benefit from thirty years of additional research and design to minimize collisions. Not to mention that climate change will kill birds too. It’s not like this is a uniquely human catastrophe.

So the next time you hear or read someone argue that wind energy is mass extinction for birdkind because Altamont kills 4,700/year, remember: the first large-scale wind facility in North America, constructed before environmental assessment was introduced, with at its peak nearly 9,000 small, old-style turbines constructed in a major migratory zone and population centre for birds, still kills only about one bird per turbine per year. Therefore one can assume that the half-dozen-odd new turbines constructed in a farmer’s field will kill only a few birds per year, which is on the order of how many birds likely fly into your lighted windows, to die on your driveway and be eaten by the neighbourhood cats.

We absolutely can and should do everything we can to minimize bird fatalities at wind energy facilities. There’s nothing to be gained from doing otherwise. But having minimized it, we need to accept that there will be some losses and get on with it–just as hundreds of birds die every year flying into the average mirrored skyscraper, and, hell, thousands of people die on highways every year, but we don’t stop building those.


*Raptors are birds of prey such as hawks and eagles. All predators are highly sensitive to even small losses because their populations are so small to begin with: a large population of plants supports a smaller population of herbivores supports a smaller population again of omnivores supports a very small population of carnivores, a la the trophic pyramid. Thus while fairly large losses of herbivores can be sustained without threatening the species as a whole (I’m not saying that’s a good thing), the same cannot be said for predators. Many raptors are already endangered, and have difficulty sustaining even small additional losses.

** As of the end of 2005, according to an email with Bob Aldrich of the California Energy Commission in December of 2008. This number declines every year as older, smaller turbines are taken out of commission and replaced with fewer, larger ones.

Looking for more information? Try the Audubon Society and the American Bird Conservancy, both of which support wind energy. So does Canada’s World Wildlife Fund, though we lack a bird-specific equivalent. Wind power: good for wildlife.

2 thoughts on “Altamont Wind Pass and Bird Mortality

  1. I’m reviewing the Altamont Bird Strike studies.

    Smallwood reports nearly as many Altamont owl deaths in the winter months as in the summer months. However, wind barely blows in the winter months and in some winter months the windmills will spin 1 or 2 days at most. As I read through all the studies I’m trying to understand how a non-spinning windmill can kill birds nearly as efficiently as spinning windmill.

    He reports 1/7 of the burrowing owls kills in Jan and Feb where less than 3% of the power is produced and most of that power is gathered in just a few days of the month.

    Further, I also note that nearly each time a study is made, the rate and number of Altamont bird strike deaths goes up despite fewer wind mills in operation over the years.

    Anyways, I would dispute or at least I’m very skeptical of the claim that Altamont Pass Wind Farm is killing a lot of birds.

  2. Good point. It does suggest that something other than windmills may be responsible.

    As far as increasing bird deaths go, though, that depends. The methodologies for counting fatalities have changed quite a bit over the years, and now capture a lot more than they used to (they look farther afield, look for bird pieces as well as entire birds, try to get there before the scavengers do and account for what scavengers have already picked up, and so on). Some of the increase is almost certainly due to simply getting better at counting.

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