Photographer friend Jerry Downs posted a lovely photo of an orange spotted housecat sitting on a car hood enjoying a rare bit of sunshine during an otherwise bleak and rainy week. And of course someone had to go and spoil it all by stating how every single outdoor cat was responsible for 500+ songbird deaths in North America. (To the tune of 3.6 million birds a day, or 1.3 billion birds a year). A bird and a half a day per cat? Do the math. Who comes up with this stuff?
To wit, I replied—The cat bird-kill statistic is somewhat inflated....that would be something like a bird and a half per day per cat. I don’t think so. Besides, not all free roaming house cats kill birds. In fact, most pet cats are clumsy lummoxes. Easy targets like lizards and mice run in front of their noses and they hardly know what to do with them. They’re not the ferocious hunters they’re cracked up to be. Besides the males (he’s orange, therefore, has an 80% chance of being male) rarely, if ever, hunt.
Since the 1970s, most of the bug population too has plummeted—especially butterflies and bees. Birds eat bugs and pesticide-laden seeds and other birds. They are apex predators. But when it comes to bird deaths, people’s free range pet moggies are unfairly bearing the brunt—convenient scapegoats for all the bird deaths.
We’ve also systematically killed off or destroyed most of the wild birds’ natural habitat, and also their predators—from kestrels and hawks to cougars and bobcats to foxes, coyotes and wolves— which was never factored in on the annual estimated bird population death counts.
Instead look to climate change, bird habitat loss, exposure to chemicals, fertilizers, insecticides, and collisions with man-made objects—from cell towers, windmills, airplane engines to cars and windows. A billion birds a year die from colliding with windows. Human impact (and the continued use of pesticides) is the real threat" to songbirds.
That said, I’m not for vast colonies of feral cats. They don’t belong here. They should be eradicated. But when someone’s pet moggie sitting outside on a car hood enjoying a spot of sunshine, being held responsible by proxy for massive bird deaths, is a bit over the top. Talk about killjoy.
SEGUE
Just for a lark, I decided to clock my cousins’ outdoor cats, two lovely calico tabby girls who are fierce hunters. Though they sleep indoors at night, they are practically feral. Now I’ve had many, many indoor and outdoor cats and most are absolutely lousy at hunting— they might kill a token lizard or gopher from time to time but that’s about it. Usually they play with it, grow bored, and then sit on it. The lizard often escapes to live another day.
But these two cats are different. They are truly ruthless hunters. However, we live in the country and they have lots of room to roam. Here’s the catch. They mostly bring home baby gophers, field mice, a vole or shrew, lizards or rare skinks, and lots of bugs. They always yodel and yowl as they trot up the driveway, to announce their success, and then they stash their prey under the old towtruck. They never eat their prey in the field.
During the past three years I’ve been monitoring their prey intake, I have found a few half-eaten lizard carcasses, random gopher feet, a tail or two, but never piles of feathers. So far, I found only one feather stash in three years, not good bird kill averages. They’re certainly not averaging three birds a day between them.
I spend most of my days (especially during the Pandemic) sitting beneath a madrone tree that’s also a haven for birds. Sparrows, wrens, titmice, chickadees, nuthatches, bluebirds, swallows, finches, grosbeaks, bluejays and orange-ass towhees. These two fiercely successful predators have incredibly lousy luck stalking even the smallest of song birds who are much savvier than they are. Of course the toewhees are fearless and will practically hop right up to the cats who ignore them.
Birds aren’t that dumb. They can see the cats, even though they blend in well with the dirt, or dry grasses. They can see them coming. It’s a game of bird and cat. Maybe urban birds are way dumber than our country birds. But this little macrocosm does not even remotely support the statistics of those reported bird deaths.
Should you happen to have a free range moggie with a taste for fowlish feathers friends, there’s an app for that, a splashy Elizabethan style collar ruff that the birds can see a mile away.
NOTES
According to the Atlantic article, there are 8.4 million pet cats (who goes around counting cats, how long does it take to count all the cats in America, and how can that count even be close to accurate?), and 4.6 million of those cats have outside access. That does not mean they are all catching birds, that’s an assumption being made. Besides, it’s not even measurable.
The article states that the feral cat population in the US is somewhere between 30 and 80 million cats. I’d suspect that they are the real culprits. Not Fluffy. However, the estimates are as flagrant as the Powerball meme circulating on Facebook. So let’s play with the math. Suppose all 34 to 84 million cats were successful bird hunters, now divide that number (both high and low estimates) by 1.3 billion. You can see that the claims are impossible—even if you can’t do the math.
1,000,000,000 (one billion) is 100 million.
1.3 billion dead birds / 4.6 million hungry pet cats
(most are unlikely to bag more than a bird or two in a lifetime). = 282.60896
1.3 billion / 4.6 million / 365 days = .77 birds a day
(but we still need to add in the estimated feral cat population)
1.3 billion / 34.6 million total cats, both feral and domestic low estimate = 37.5722543
1.3 billion / 34.6 million / 365 = .10 birds a day per cat
1.3 billion / 84.6 million total cats, high estimate = 15.36643026
1.3 billion / 84.6 million / 365 = .04 birds per day per cat.
The headline states:
“The continent has 3 billion fewer birds than it did in 1970.”
Then it states: “Other threats are easier to quantify, and the biggest of these, by some margin, is domestic cats, which kill an estimated 2.4 billion birds every year.”
Do you see the applied math problem? If we have 3 billion less birds since 1970, then cats can’t be blamed for killing 2.4 billion birds a year. The math is wonky. Even if the “per year” clause were dropped, the statement is still false. It doesn’t take massive critical thinking skills to see through this false syllogism, just basic reasoning skills.
1,000,000,000 (one billion) is 100 million.
1.3 billion dead birds / 4.6 million hungry pet cats
(most are unlikely to bag more than a bird or two in a lifetime). = 282.60896
1.3 billion / 4.6 million / 365 days = .77 birds a day
(but we still need to add in the estimated feral cat population)
1.3 billion / 34.6 million total cats, both feral and domestic low estimate = 37.5722543
1.3 billion / 34.6 million / 365 = .10 birds a day per cat
1.3 billion / 84.6 million total cats, high estimate = 15.36643026
1.3 billion / 84.6 million / 365 = .04 birds per day per cat.
Outdoor cats kill between 1.4 billion and 3.7 billion birds a year, study says Researchers estimate one pet cat kills between one and 34 birds a year, while a feral cat kills between 23 and 46 birds a year..
The Quiet Disappearance of Birds in North America Though the continent has 3 billion fewer birds than it did in 1970, those losses are hard to glean because it’s the commonest species that have been hit hardest.... the continent’s bird populations have fallen by 29 percent since 1970. That’s almost 3 billion fewer individuals than there used to be, five decades ago... 90 percent of the missing birds came from just 12 families, and that they were all familiar, perchy, cheepy things such as sparrows, warblers, blackbirds, finches, larks, starlings, and swallows.... About 19 species have each lost more than 50 million individuals.... habitat loss and degradation are the largest forces behind the decline of birds... domestic cats, which kill an estimated 2.4 billion birds every year. Window collisions claim 600 million bird lives a year, vehicles take out 214 million, power lines are responsible for killing 32 million, and the lights of industrial towers fatally distract about 6 million. Wind turbines...Cats are not the problem. We are. Not only have we destroyed bird habitats wholesale, we’ve poisoned what’s left with pesticides. The cat to bird kill ratio is from one report from a long time ago, and that number has been inflated and bandied about ever since. Parrot statistics and peculiar math equals a convenient half truth.
The headline states:
“The continent has 3 billion fewer birds than it did in 1970.”
Then it states: “Other threats are easier to quantify, and the biggest of these, by some margin, is domestic cats, which kill an estimated 2.4 billion birds every year.”
Do you see the applied math problem? If we have 3 billion less birds since 1970, then cats can’t be blamed for killing 2.4 billion birds a year. The math is wonky. Even if the “per year” clause were dropped, the statement is still false. It doesn’t take massive critical thinking skills to see through this false syllogism, just basic reasoning skills.
A REBUTTAL
Jeff Nelson, a member of the California Native Plant group on Facebook wrote this article which offers an alternative explanation.
ARE CATS REALLY KILLING ALL THE BIRDS?After I finished the above, I found the following after a quick Google search. Please have a look and consider this...
by Jeff Nielson (October 2016)
Recently on the ABC News, they said that billions of birds have disappeared partly because of cats. One only has to ask the question: Did cats eat all the bees that died about the same time? What about the butterflies, lady bugs, praying mantises, bumble bees? Did the cats eat them too? Are there cats running around in the water eating shorebirds that have been reduced to a third? The CBS News Report on this was much more accurate. Here is my article...
I first heard that cats were killing songbirds listening to NPR on my car radio in 2016, and back then I believed it, but now I’m not so sure. It’s easy to blame the disappearance of many song birds on cats, but all one need do is ask themselves: How long have cats been around? And how long have birds been largely absent from most areas?
That’s right, domesticated outdoor cats and feral cats have been roaming free just like they are now for over a hundred years, but the great majority of songbirds started disappearing about THE SAME TIME THAT THE HONEY BEES DID, in addition to the butterflies, ladybugs, black and yellow bumble bees, praying mantises, dragon flies, and more...
This observation is further supported by the fact that in some neighborhoods there aren’t enough outdoor cats or feral cats to touch the bird population. (I’m living such a neighborhood right now.) And how does one explain the absence of birds in neighborhoods like mine with very few cats, basically no young cats, and no feral cats?
Then add to this, the fact that many cats never go after birds. Some don’t even want to, many are too slow. That’s just a fact...
And, last but not least, birds often perch high up and build their nests in trees that most cats simply do not climb.
“And yet there are serious reasons to suspect the reliability of the new, extreme cat-killer statistics.The study at issue is a meta-analysis, an overarching review that aggregates data from previously published sources. The accuracy of meta-studies in health and medicine raises some concern, and it's easy to see why: for a meta-analysis to be solid, wise choices must be made among the available sources of information, and results that may vary wildly must be weighed fairly.”. Do We Really Know That Cats Kill By The Billions? Not So Fast
and
“…these numbers make absolutely no sense. Nobody knows a damn thing about what they’re talking about when it comes to feral cats and the death of songbirds. It won’t take long to get to the bottom of this.According to the American Veterinary Medical Association U.S. Pet Ownership Statistics survey conducted in 2012, there were 74,059,000 cats in American homesMy first question is who’s counting US feral acts – if you Google the term “feral cat population US” it looks as though the number seems to be 50 to 60 million feral cats in the United States.I found another study entitled New Research Suggests Outdoor Cats Kill More Wildlife Than Previously Thought from the Wildlife Management Institute claims about 30% of feral cats were successful in capturing and killing prey or about 2.1 kills per week on average. Let’s say one of those meals is Tweety Pie.“If we extrapolate the results of this study across the country and include feral cats, we find that cats are likely killing more than 4 billion animals per year, – or about 14% of the USA Today study “estimate”If you read the USA Today story they claim that Cats that live in the wild or indoor pets allowed to roam outdoors kill from 1.4 billion to as many as 3.7 billion birds in the continental U.S. each year.But they go on to say about a third “of the 800 species of birds in the USA” are endangered, threatened, or in significant decline, according to the American Bird Conservancy – really?I took the list from Wikipedia List of birds of the United States listing about 1700 species – by name – more than double the estimate of the American Bird Conservancy – if I had the time we’d track down the number of migrating birds going from one continent to another who landed in America which probably adds another two or 3000 or 4000 species of birds on American soil throughout the year – which gives all of these studies even less credence.”Debunking the Myth of Feral Cats Devastating Us Songbird Populations
No comments:
Post a Comment