My buddy is a zoologist in Florida. Says the same thing. They did a study and concluded feral cats are killing more natives than terrestrial invasive species there.
I agree. There have been numerous studies done on how detrimental feral and free roaming cats can be on native species. Unfortunately every time they attempt to do something kitty loving animal rights activist step in and promote the Trap Neuter Release program. This program is meant to be a happy medium that controls the population without killing the cats. Unfortunately, while being hailed as a great solution, it in all actuality does nothing. It allows the animals to stay in place wreaking havoc and as soon as one dies another moves from one of the meta populations effectively holding the populations where they are. When people promote this program they allow their emotions to over power logic. As someone who works on a daily basis doing bird and amphibian surveys it makes me want to pull out my hair in frustration.
Ecological management is a complex and very difficult issue. There's a lot more than just killing feral cats or removing invasives and reintroducing the native species. Not all invasive species are bad but some are horrible.
I know cats have impacted our quail populations and are putting a serious dent in the population, however how do you explain to the five year old the next farm over that you shot his beloved tabby?