It's hard to tell. This is the city and we are surrounded by businesses on two sides and then large sprawling houses on the other. Some estimates put it at 250+. I rather doubt that since the coyotes (desperately hungry with the drought) moved in and have settled in the woods on the campus.

The Austin Humane Society recently captured, neutered/spayed, and released some 650 cats. Other organizations also work to prevent growth.

That said, one reason we feed even the ones we can't get near to catch is because they keep the rodent population at bay. When Round Rock exterminated their feral cat colonies, they were overrun with black "roof" rats. It was pretty awful!

We have no rodents even with the huge dumpsters outside the fast food locales full of rotting food.

Thanks to the feral cats!