The one mind-blowing stat from that show, if I heard it right, is that in Australia, feral cats kill 75 million animals each night. Even if I misheard it and it was actually 7.5 million or something, it's still amazing. They listed several species that have gone extinct as the result of overpredation by feral cats. The disappointing thing from my perspective was the complete lack of understanding from the well-meaning people who insist on feeding the feral cats, which doubtless boosts their numbers (despite the neutering program), even in the face of video evidence that the cats eat at the urban feeding stations until chased out by raccoons, opossums, and skunks. They maintain that if they don't feed the cats, they'll die. This reminds me of when somebody in my hometown dynamited a beaver dam, and a bunch of misguided people organized to sandbag the breach, believing that they were saving the lives of the beavers, when in fact if there were still any beavers present in the pond, they could repair the damage much faster than the sandbag brigade could.
There was another NPR show a while back that explained the amazing effort that had taken place to extirpate feral goats from one of the Galapagos islands, where their presence had been very detrimental to the native tortoises. The goats aren't all gone, but they've shot huge numbers of them, and the tortoises are rebounding.
Oh, interesting that they said trap-neuter-release programs aren't having much success. I'd heard good things about them but never actually researched it.
Pretty sure 3 million cats and dogs are euthanized every year in the US, down from 20 million a few decades ago, so your theoretical tens of millions are actually not crazy, even though that sounds like a lot of lives.
Cats can have four litters a year and don't take long to reach sexual maturity so I suspect you're right that reproductive rate is not the limiting factor or we would all be drowning in cats. There are clearly more cats out there than anyone wants though so higher rates of spaying/neutering seems useful. If everyone altered their pets, the feral population in your thought experiment wouldn't rebound.
I'm pretty happy our cat is indoors only. She won't get eaten by a coyote or hunt anything herself.
I think that was a Radio Lab show about the Judas goats on the Galapagos. It was a fantastic story.
Oh, I guess they did manage to wipe out all 100000 goats
, as well as pigs and donkeys.
Are cats susceptible to myxomatosis? Maybe that could be introduced to the feral population to solve this human-created problem. In Australia... oh wait.
Which are the wild animals that are suffering? If it's mainly mice, then I thought those were in need of predators anyway, according to the people tracking the spread of Lyme disease?
I'm not sure how this paper breaks down the mammal category. I would expect many of these are mice and rats, but they may also include a substantial number of native mammals.
It was my impression from the article that the impact on wildlife has been more comprehensively studied in Australia, but a very cursory glance at the peer reviewed literature seemed inconclusive. The wikipedia article has some references:
This government website claims that feral cats threaten the survival of over 100 native species, though I haven't personally examined the data:
Sounds like a job for OUSA.
Feral cats help themselves to a phenomenal number of species in Australia – 400 different vertebrates. This includes 123 bird species, 157 reptiles, 58 marsupials, 27 rodents, 21 frogs and nine exotic medium- and large-sized mammals.
The Australian Wildlife Conservancy (AWC) says that cats eat between five and 30 native animals a night and then they multiply this figure of five by 15 million cats to estimate that feral cats eat 75 million native animals each night.
How about the Feral Dogs of Kiev? (I'm not speaking of the Russians.) A bigger problem, per unit.
Ought to address (joining a long queue).