I know it is a scientific study published in Nature that the NPR article is based on. Cats kill birds, I have zero doubts, cats kill lots of birds, that’s likely. Cats kill as much as that estimate says, I have significant doubts. For multiple reasons:
Whenever a predator kills a bird there will be traces such as a bunch of feathers and inedible parts at the location of the kill and/or consumption. Never seen a single one of those.
It is a single estimate, never replicated.
There are hundreds of starlings, tits, and other small birds in my neighbourhood. It’s not like birds are a scarce resource. Nether do they seem especially held back by the local cats.
> there will be traces such as a bunch of feathers and inedible parts
When my family lived in Hugo MN (north of St. Paul), we regularly saw feathers and other remains left by our cats. Occasionally they would leave a bird (or mouse) half dead on our kitchen floor... as an offering? Note that cats might not leave a lot of remains when they hunt, and the sometimes hide the parts they do leave.
Also, while our cats regularly hunted birds, the local blue jays liked to hunt our cats... for sport. The would send one bird out at one end of the yard as bait, and wait for the cat to start hunting it, creeping slowly towards the bird. Then another bird (or several) would suddenly dive bomb it from behind, dropping 20-25 feet strait into the cat's rear end. Our cat would end up launched (and/or leaping) 6+ feet in the air.
Animals must die all the time with minimal evidence left for humans to see. The lack of bodies is just indicates that the animal was rapidly consumed. Whenever I have seen dead birds outside they never last long.
My cats aren’t/weren’t subtle when they catch and eat prey. Neither are birds of prey or other vultures, when devouring another bird.
The cats I own and had over the past decades have gifted me hundreds of dead of half dead animals. Some of those cats were prolific killers.
I never witnessed a successful bird hunt, never received a bird as a gift. And most importantly: If there is any single animal which can easily leave traces of inedible stuff like feathers, down, beaks, claws — it’s birds. I never even have found traces of a killed bird, on the ground or in scat.
Despite this, I have no doubt cats kill a lot of birds. It’s just that a lone study with p<0.1 (rather than the classic p<0.05) is so far removed the reality I actually observe I can’t help but to have my doubts.
Whenever a predator kills a bird there will be traces such as a bunch of feathers and inedible parts at the location of the kill and/or consumption. Never seen a single one of those.
It is a single estimate, never replicated.
There are hundreds of starlings, tits, and other small birds in my neighbourhood. It’s not like birds are a scarce resource. Nether do they seem especially held back by the local cats.