Which Kills More Birds?

Windmill and Cat named Lilith (photos from Wikimedia Commons)

In case you missed it last week, the numbers have changed.

The Smithsonian Conservation Biology Institute and U.S. Fish and Wildlife Service developed a mathematical model, used data from 21 of the most rigorous cat-wildlife studies, and ran the numbers on cats.

The results were quite surprising.  2.4 billion birds are killed by cats every year in the U.S.  That’s two to four times the old statistics.

Compare this new data to other human-induced causes of bird mortality(*) and cats are now on top.

  • Cats: 2.4 billion
  • Windows: 1.0 billion
  • Power lines: 0.174 billion
  • Communication towers: 0.051 billion
  • Windmills: 0.0004 billion

So you can stop worrying about windmills.

If you want to save birds’ lives, keep your cat indoors.  I do.


Read more about this study including information on feral and pet cats in the New York Times.

(photo of windmill and a former stray cat named Lilith, both from Wikimedia Commons.  Click on the imbedded links to see the original photos)


(*) p.s. I’m not sure where habitat loss fits in now, but it has always been the leading cause of human-induced bird mortality.

p.p.s. I love both birds and cats.  Here are two posts about my beautiful indoor cat Emmalina (also known as Emmy):  Mouse in the House and Animal, Vegetable.

4 thoughts on “Which Kills More Birds?

  1. There was an article in our local paper recently about feral cats impact on the bird population. The writer was not in favor of a program which captures feral cats, neuters and releases them. There’s lots of emotion on all sides of this problem and no easy answers, as far as I can see.

  2. Wow that’s a lot of birds….can you imagaine what the bird populations would be like if there was no human-induced mortalities?

  3. Karen…I CAN imagine it…
    although I will never get the chance to see the passenger pigeon as it had existed…My anscestors robbed me of that experience…..
    Here is a newer book to look up for the info on that extinct species:
    The Passenger Pigeon: Its History and Extinction
    A.W. Schorger

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