Earthsky

Private: Birdkiller!

A lot of people aren't going to want to know this ... It's information that's probably easier on dog lovers.

05-16-2007 - Biodiversity

In my yard, the songbirds have returned – they are noisily chirping right outside my window. They sound happy – at least they make me feel happy — and I wondered what dangers they had to overcome to make it back here to my yard from their winter south.

There have always been natural obstacles for migrating birds: bad weather, predators, and the struggle to get enough to eat.

But I wondered what new obstacles the modern human world has introduced.

I know there’s “towerkill”:http://www.towerkill.com. No one knows the exact number of songbirds killed in collisions with tall communications towers, but according to U.S. Fish and Wildlife Service, it’s somewhere between 5 to 50 million birds per year.

That’s seems like a lot of birds. Is that the worst the human world has dished out?

I asked “Cagan H. Sekercioglu”:http://www.stanford.edu/~cagan/main.html, conservation ecologist, ornithologist, tropical biologist, (and “nature photographer”:http://www.naturalphotos.com/sekercioglu/galleries.html) at Stanford University.

He told me that another important hazard is habitat loss.

bq. “_Millions of birds rely on critical migratory stopover sites that they have used for hundreds or thousands of years. If these sites are developed, when the birds come back next year, exhausted after a long flight (eg crossing Gulf of Mexico) and there is now suburban housing, then they are in big trouble._”

And here’s something else he said that I bet a lot of people won’t like to hear.

bq. _”In connection with that, increasing numbers of domestic and feral cats take a massive toll on migratory birds, especially songbirds.”_

How much of a toll?

“100 million birds are killed each year by house cats” – “National Audubon Society”:http://www.currykerlinger.com/birds.htm.
“39 million birds are killed by cats each year in Wisconsin alone” – “University of Wisconsin’s John Coleman and Stanley Temple”:http://www.ctaudubon.org/conserv/nature/cats.htm

Dr. Sekercioglu told me that birds are especially vulnerable during the migration seasons.

bq. _”After a long flight or after a storm birds can be so exhausted they can barely move. I witnessed this myself at High Island Texas, when one evening it was raining birds. The trees and bushes were full of yellow-billed cuckoos, painted buntings and many others that had just crossed the Gulf. These birds are very vulnerable to cats and other introduced predators.”_

Cats are now the most popular pet in the U.S. And they’re excellent hunters. Neither my brown dog nor my yellow dog is stealthy enought to get a bird.

So what to do? Many bird conservancy groups recommend keeping cats indoors. I don’t have a cat that I love, so it’s hard for me to know. But I imagine a lot of hair and scratched funiture …

Let me know where you stand.

Written by Eleanor Imster

16 Responses to “Private: Birdkiller!”

  1. Alley Cat Allies - www.alleycat.org says:
    March 28, 2007 at 2:44 pm

    I am appalled that Earth&Sky, a website claiming to be a clear voice for science, would endorse Stanley Temple and John Coleman as cat predation experts. Temple’s primary work on this subject has never been published or peer-reviewed and has been severely questioned by the scientific community for more than a decade. According to a published leader in the field, “Any bird populations on the continents that could not withstand these levels of predation from cats and other predators would have disappeared long ago.” (B.M. Fitzgerald, Ecology Division, Department of Scientific and Industrial Research, New Zealand).

    Two studies most often quoted to support placing blame on feral cats are the Stanley Temple study – mentioned above – (often called the “Wisconsin Study”) and the Churcher/Lawton study. Some individuals and groups use these studies in misguided efforts to discredit Alley Cat Allies’ and others’ work to humanely control feral cats. However, there are many other studies on feral cats written from different continents throughout the world—all showing three very important points:

    • Cats are opportunistic feeders, eating what is most easily available. Feral cats are scavengers, relying mostly on garbage and handouts from people;
    • Cats are rodent specialists. Birds make up a small percentage of their diet when they rely solely on hunting for food
    • And, cats may prey on a population without destroying it. If this were not so, there would no longer be any mice.

    Further, the Audubon Society’s 2004 State of the Bird report, the Watch List consisted of 201 bird species. In the discussions of why each species was listed, cats were only mentioned as a problem of any kind for 20 species, and 11 of those were in closed ecological systems on islands.

    For more information about Trap-Neuter-Return (TNR) as the management program for outdoor cats, check out http://www.alleycat.org.

    Reply
  2. Amy F. says:
    March 28, 2007 at 2:44 pm

    Yet another solid argument for keeping cats indoors, the others being it’s healthier for them (less exposure to disease) and safer (they won’t lose fights with cars, other cats, and other predators).

    Anyone who is uptight about hair and owns expensive furniture shouldn’t get a cat. :)

    Reply
  3. Reason says:
    March 28, 2007 at 8:32 pm

    Wow. 100 million. 39 million. Those are large numbers.

    If only this “news” article ALSO contained the total number of birds on the continent at any given moment, so that the “news” consumer would know whether 100 million was significant or not.

    Science? Reason? or just a different Religion?

    Reply
  4. Rubylikeaflame says:
    March 28, 2007 at 9:20 pm

    Answer to #3 above. Whether it’s 100 million or 39 million, that’s a lot of little bird deaths every year! I’d say it’s “significant.”

    Reply
  5. Kenneth Crook says:
    March 29, 2007 at 6:09 am

    Before modern man and the domestic cat there were many natural predators that took a large toll on song birds, such as hawks, foxes and bobcats, that are now in reduced numbers. So the current song bird loss to cats is probably not much changed from the past.

    Reply
  6. alice smith says:
    March 29, 2007 at 7:20 am

    Please give me a clue how i can deter cats from my yard!!!
    Thanks

    Reply
  7. Cagan Sekercioglu says:
    March 30, 2007 at 1:19 pm

    To keep your cat from killing birds, here is an interesting solution – the ‘cat bib,’ which I had recommended on NPR in 2004 : http://www.catgoods.com/index.html

    . .. and now this scientific study in the journal Biological Conservation has shown that it reduces bird predation by 72%. This 72% reduction in the numbers of birds caught by cats fitted with a CatBib compares favourably to the figures of 34% for bells alone and 38% for electronic warning devices alone (Nelson et al. 2005).
    http://www.kuow.org/defaultProgram.asp?ID=8165

    The cat bib is a cheap, effective product cats get used to in a day or two, and there is no justification for not using it. I don’t know these people and do not benefit from their sales.

    Cagan H. Sekercioglu, Ph.D.
    Senior research scientist
    Stanford University
    Department of Biological Sciences
    http://www.stanford.edu/~cagan/main.html

    Reply
  8. Eleanor Imster says:
    March 30, 2007 at 1:24 pm

    I found an estimate of US bird numbers by a very respectable ecologist. It is 5.7 billion birds.

    That means that there are only 19 birds for each person in the USA.

    Rosenzweig, M.L. (1995) Species Diversity in Space and Time. Cambridge: Cambridge University Press.

    Reply
  9. Eleanor Imster says:
    March 30, 2007 at 1:32 pm

    Contrary to the comments above, the Coleman & Temple paper not only has been peer-reviewed, but it has also been cited 22 times on ISI Science Index Citation – and that’s a very respectable number.

    (the Science Citation Index — http://scientific.thomson.com/index.html — is a way scientists measure their impact. It’s similar to Google Scholar, but it’s carefully checked to remove duplicate references etc.)

    Reply
  10. David LaFerney says:
    March 30, 2007 at 5:08 pm

    I don’t know what the “cat bib” is, but a little bell on the cat’s collar is the classic way for frustrating a cat’s (or dog’s) predatory instincts. Cheap, simple, effective.

    Reply
  11. Linda Keller says:
    March 31, 2007 at 1:38 am

    Just this morning while walking to my car I stopped and listened to the glorious sound of chirping birds. So what if I’m a minute late for work. Their sound says to me, everthing’s erased, this is a new day.
    I NEED THESE SONG BIRDS.

    Reply
  12. Allen Lipke says:
    April 2, 2007 at 9:33 am

    I have a cat we have had a cat for 25 years and it has NEVER been on the loose outside. I don’t see any reason to let it roam. It likes to sit in the sun on the deck but that’s far enough. I would like to see cities have leash laws for cats but I doubt that will happen. The bell around its neck is a good idea and works.
    It seems to help to have a dog to keep cats out of your yard. It must be a territory type thing.
    Al in Hibbing

    Reply
  13. jessie says:
    April 4, 2007 at 1:38 pm

    the kittie is sooooooooooooooooooooooooooooooo cute i just want to eat it up.Exsept for the fur part….. Fur ball

    Reply
  14. katapalooza says:
    April 10, 2007 at 1:55 am

    I hate to tell the guy with the yellow and brown dogs who don’t go after birds, my sister’s dogs (boxers&bulldog) all were vorascious killers of small critters including birds. Yes dogs are natural predators like cats and do kill small creatures. Further Idon’t by how cats are the scourge of the earth merely because they are predatory , yes they can have impacts on wild life but just how much of that is correct is open to serious debate. Habitat destruction takes a toll on more wild life than cats. People need to tread lightly on Mother Earth.

    Reply
  15. gale says:
    April 19, 2007 at 8:43 pm

    I just ordered the cat bib. My cat killed a beautiful bird yesterday with her bell collar on.

    Reply
  16. GEZ says:
    May 16, 2007 at 2:44 pm

    There are way too many birds in the world, eating all those seeds, causing global warming (this is a proven study but I can’t give you the details – it’s a secret). Birds also bring down airplanes by aiming for the engines. I also got pooped on a bird once. Let’s get more cats, then maybe I’ll get some sleep when the sun comes up in the morning!

    Reply

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