State of the Planet

News from the Columbia Climate School

Cats and Wind Turbines – A Bird’s Two Greatest Fears

Gray Catbird seen in Washington, DC, USA.

First reported in a NY Times article, a new study in the Journal of Ornithology reports that cats are responsible for the death of many gray catbirds in Washington D.C.. Seeking to calculate the fraction of bird deaths attributed to cats, researchers at the Smithsonian Institution and Towson University placed radio transmitters on baby catbirds. According to their results, they found that close to 80 percent of the birds had been killed by predators; cats were responsible for 40 percent of those deaths. Emphasizing the importance of addressing cat predation, The American Bird Conservancy estimates that pets and feral cats kill nearly 500 million birds each year. Still, more danger lurks for birds in places cats cannot reach.

According to the United States Fish and Wildlife Service, wind turbines kill nearly 450 thousand birds each year; this number is expected to increase dramatically as demand for wind farms are met. Let’s face it – birds have a knack for colliding with human-made objects, crashing full speed ahead into freshly cleaned windows and stealthy power lines. Why do birds fail to avoid structures of impending doom?

Recently published in the International Journal of Avian Science, this new study helps us better understand the world through the lens of a bird. Professor Martin from Binghamton University explains in Science Daily the complexities of a bird in motion -“When in flight, birds may turn their heads to look down, either with the binocular field or with the lateral part of an eye’s visual field,” said Martin. “Such behaviour results in certain species being at least temporarily blind in the direction of travel.” In addition, the researcher explains that birds detects movement, rather than spatial detail, and are restricted to only a few flight speeds, making it difficult for them to stop in time. When rain or lights further cloud visual information, it becomes increasingly harder for a bird to navigate the sullen skies.

If we want to reduce bird collisions, keeping the cats inside and leaving the windows dirty may not be enough. The study reminds us that humans see the world differently than their co-animalia-inhabitants; we must account for such sensory variation to develop and deploy effective efforts of conservation.

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Recent record-breaking heat waves have affected communities across the world. The Extreme Heat Workshop will bring together researchers and practitioners to advance the state of knowledge, identify community needs, and develop a framework for evaluating risks with a focus on climate justice. Register by June 15

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Peter J. Wolf
13 years ago

I’d like to clarify/correct a few points, if I may…

The NYT story, like those on the Smithsonian Website and elsewhere, is highly misleading.

As the paper published in the Journal of Ornithology makes clear, the researchers witnessed just SIX catbird deaths due to predation by cats. That’s six of 42 total mortalities. They then attributed THREE more to cats on the basis of decapitated remains because, as they explain, “we are unaware of any other native or non-native predator that regularly decapitates birds while leaving the body uneaten.”

In fact, it’s rather widely known that such predatory behavior is not at all uncommon with owls, grackles, jays, magpies, and even raccoons.

Even if the Smithsonian’s Pete Marra and his colleagues are correct about the three additional kills, the title of “primary predators of young catbirds” goes not to the cats, but to the “unknown predators” (with 14 kills). Seven kills were attributed to rats or chipmunks.

This isn’t quibbling—not when we’re talking about the kinds of conclusions the researchers draw (and invite others to draw), and their potential consequences.

Also, it’s irresponsible of these researchers to declare two of the study areas to be dispersal sinks—habitats in which reproduction is unable to keep pace with losses, and which are therefore relies upon recruitment from nearby areas. This, largely on the basis of 19 fledgling mortalities, observed over five months—seems like quite a stretch. It’s akin to making conclusions about climate change on the basis of a single season’s weather.

Readers may be interested to know that Marra, along with several of his colleagues, made his position on free-roaming and feral cats very clear in a letter last year to Conservation Biology. Among the “highlights” were the authors’ assertion that “trap-neuter-return [a humane approach to feral cat management] is essentially cat hoarding without walls,” and a demand for “legal action against colonies and colony managers.” The authors also call on conservation biologists to “begin speaking out” against TNR “at local meetings, through the news media, and at outreach events” (a message Marra has obviously taken to heart).

Given how poorly the Smithsonian and others have covered this story, it’s difficult not to conclude that the people involved are far more interested in perpetuating the shameful witch hunt against feral cats than they are in either science or journalism.

Peter J. Wolf

Sea Green
Sea Green
13 years ago

The NY Times article you mention says “Researchers found that cats were responsible for nearly half of the predation on baby gray catbirds.” If you read the actual paper, you find those numbers were arrived at, only after the researchers removed any other data that could interfere with that conclusion.

Quote from the study: “Predation accounted for 80% of all mortalities, with 47% of known predation events attributable to domestic cats.” Simply stated, of 100 birds, if 80 were killed by predators, then 37(47% of 80) would have been killed by cats, but the study recorded only 6 birds directly observed killed by cats. The authors added another 3 birds to the cat tally because they believed, without proof, that cats killed them. In other words they inflated the cat kill numbers to appear larger.

In the original study, the authors say 42 of 69 fledglings died, 33 by predation events (there’s the 80%). Nine cat kills out of 33 predation events is 27% not 47%. Where did the 47% come from? Oh, the authors manipulated total predation numbers, until the 9 cat kills appeared significant. They did this through language not scientific results. They reduced the total predation deaths from 33 to 19, by including only “assignable predation events”, discarding 14 unknown-predator predation events. Nine of 19 is 47%. Making it look like cats were the major predator.

Habitat destruction is the major cause of bird decline, followed by window collisions (one billion a year), then hunting. If all the feral cats were eliminated and all the domestic cats kept indoors, bird numbers would continue to decline because of habitat destruction. It’s easier to blame cats than to speak up about human overpopulation the driving force behind habitat destruction.

13 years ago

Here’s a little insight to help you with your war on cat-lovers and their cats. Now you’ll know why cat-lovers actually do what they do. Maybe if you explain this to them you won’t have to use more drastic means.

Human Territorial Behavior By Expendable Proxy

I have come to the inexorable conclusion that the vast majority of cat-lovers and cat-owners that let their destructive invasive-species roam free, and those that defend the rights of feral cats to overtake public property and wildlife areas, are only (cowardly) using cats as a proxy for their own territorial behavior. Not unlike uneducated inner-city youth that will disrespectfully and inconsiderately use a boom-box to stake-out a territory for themselves with loud music. As long as they can have one of their possessions defecate in another’s yard and the yard-owner not have any recourse, the cat-owner owns that territory. It’s time to put a stop to them using their “cute kitty” excuse for usurping and stealing others’ property. If they want territory they can damn well buy it just like anyone else. Instead they’re using underhanded, disrespectful, and manipulative means by putting (and sacrificing) live animals in the path of their envy and greed. Again proving why they don’t care about cats nor anyone else at all. Cat-lovers only really want your lawn, yard, or forest while making all others and all other animals suffer for what they can’t have nor own. Bottom line–they want to control you and your property. That’s all that “cat-lovers” are really after. It’s why they don’t care at all if their cat nor any other animals, nor even other humans, get harmed by their goals and (lack of) values in life.

Dave D
Dave D
12 years ago

Trapping as a solution is a failed concept from Day-1. Considering that there are now about 150 million feral-cats just in the USA alone, and 86 million pet-cats (60 million of which are allowed to still kill wildlife), this means that the cat-population is already oversaturated for a long time now. There’s only 311 million people in the USA, 2 cats now exist for every 3 people, from infant to senior. All thanks to those who outlawed destroying them in a faster, more efficient, often more-humane, and more cost-effective manner by shooting them. While they also promoted their slow, inefficient, and failed trapping programs.

Nobody wants more than 86 million cats for pets. Now take into consideration their exponential yearly growth-rate of x^5.4. An average litter of 5 new cats every 5-6 months. 2 cats can become 42 in only a year’s time. Increasing at the rate of powers of 5.4 EVERY YEAR. No amount of people trapping them (if you could even get them all to enter traps), nor valuable resources (materials for traps, transport costs, vet costs, etc.), man-hours, nor money will ever catch up to their growth rate. You now have an ecological, human-health, animal-welfare, social, and financial disaster on your hands, ALL thanks to cat-lovers and TNR proponents. The faster that cats can be destroyed the better it MIGHT be. Even when using guns and having all stray and feral cats shot on-sight we might still not be able to catch up to their exponential growth rate. Not even until every last land animal (including humans) is gone from this earth, due to cats destroying the whole food-chain, with nothing but cannibalistic cats left walking the land. Just ask any TNR group how many cats they’ve trapped this year. They haven’t even scratched the surface of the problem that they are exacerbating with their lies.

Your best bet is to make cat-ownership AND care-taking of feral-cats a FELONY with hefty fines or prison sentences for anyone failing to comply — until this problem that they created is brought under control by any and all means possible. Though avoid non-discriminatory poisons if at all possible, that once entered into the food-chain, will go on to destroy more of the very wildlife that you are hoping to save from destruction by cats.

Here is an interesting post from someone who believed in all the lies she was told about TNR practices, found at

“I have been battling a feral cat population explosion on my farmette for 7 years. TNR does not work, as the trapped and neutered cats do not keep new cats from moving in and adding kittens. I have trapped over 25 kittens, tamed them, and found homes for them, but every spring there are dozens more. I have spent countless dollars neutering females and males, but they just keep coming! I have few wild birds now, fewer snakes, and there are bunny parts all over my property (cats must not particularly like the back feet). I wish there was a birth-control feed available, since many of these feral cats don’t come near the traps even when hungry. I wish every pet owner would neuter their cats so that these colonies weren’t added to.
These are not happy feral cats, they frequently have infected eyes, worms, and are skinny and mangey. I don’t know what the answer is, but even in the country, a feral cat doesn’t live a secure, comfortable life.

Comment by Dawn Hawes — June 21, 2011 @ 9:38 am”

And YOU TOO can have a financially-stressed life ruled by cats and cat-lovers JUST like this if you also believe in TNR.

cooler bags
12 years ago

i think there needs to be a balance between the population of the birds and those cats. Cats make good pets but cats being overprotected and loved are dangerous to the population of birds. I think humans need to find ways to balance this.

10 years ago

Feral cats are notorious for being quite invasive. I know Australia has had huge problems with them. I love cat, but when they start decimating local populations of native animals, something has to be done.