Iām gonna start by saying that I like cats.
I grew up with outdoor cats. My dad and my aunt are both veterinarians.
I also care deeply about wildlife. I went to college for ecology.
People have brought cats all over the world, and there are consequences.
Cats eat ENORMOUS amounts of native wildlife, and I see lots of fellow animal lovers and even ecologists trying to convince themselves, against the evidence, that this isnāt the case.
Hereās a study from Michigan State University showing that outdoor pet cats across the urban-rural landscape there kill at least 2.6 birds/mile^2/per day (thatās 1/km^2/day for you metric users).
Altogether, thatās between 16k and 47k killed during the nesting season in their study area.
The cats killed a diverse array of birds (23 species) including individuals from two species threatened in that state.
https://www.sciencedirect.com/ā¦/artiā¦/pii/S0006320703001071ā¦
That study only looked at birds, so hereās another one, this time showing a wide variety of prey eaten by feral, unowned cats in central Australia:
http://www.publish.csiro.au/WR/WR96023
Here they are, predating on 4% of wild rabbits and 20% of field voles a year in southern Sweden:
https://zslpublications.onlinelibrary.wiley.com/ā¦/j.1469-17ā¦
The next link estimates outdoor cat predation using American population numbers and data from across the temperate zones.
It shows 1.3-4 BILLION birds and 6.3-22.3 BILLION mammals killed annually by cats in the US.
This is a conservative estimate.
https://www.nature.com/articles/ncomms2380
Donāt (1) get (2) me (3) started (4) on (5) islands (6).
1 )Feral cats on islands are responsible for 14% global bird, mammal, and reptile extinctions.
https://onlinelibrary.wiley.com/ā¦/ā¦/j.1365-2486.2011.02464.x
2) Cats on Nova Island, in the Mozambique Channel preferentially predate and have an impact on Sooty Terns nesting.
Their diet is flexible enough that they survive on other prey during non nesting season, and they kill 22% more terns than they actually eat.
https://zslpublications.onlinelibrary.wiley.com/ā¦/j.1469-17ā¦
3) Eating shearwaters and native reptiles on an island in the Mediterranean:
https://academic.oup.com/jmammal/article/88/4/1074/908458
4) Cats caused at least 30% of sparrow deaths in English village, along with heavy mortality in other groups like small mammals.
https://zslpublications.onlinelibrary.wiley.com/ā¦/j.1469-79ā¦
5) An island in Japan shows predation on seabirds:
https://zslpublications.onlinelibrary.wiley.com/ā¦/j.1469-79ā¦
6) Increased nesting success in Greatwinged and Blue Petrels on subantarctic Marion island after feral cat eradication.
https://sora.unm.edu/sites/default/files/23_1_33-37.pdf
7) Bonus interesting model showing how multiple levels of invasive species can āwork togetherā to mess up native island ecosystems.
Also suggests that cat management efforts should be accompanied by management of other invasives they interact with.
https://www.sciencedirect.com/ā¦/articā¦/pii/S0006320798001311
The unavoidable fact is, cats are a problem in most places.
To suggest otherwise is to decide that our emotional attachment to cats is more important than the lives of billions of individual animals and many wildlife populations, and that our emotional comfort is more important than reality.
So what do we do about it?