Feral cat colonies can be a problem. Having spent years in cat rescue let me offer a couple suggestions.
- Spay / neuter your pet. Just because Tom ain't knocking up anything in the house doesn't mean he ain't hitting that Persian a block over.
- TNR. Trap Neuter Release. This method of feral colony control works very well and is humane. How this works is that traps such as
Havaheart are set out with tuna as bait. A cat will sell its soul for tuna. Set out as many as possible. Wait overnight. Early the next morning retrieve the traps and bring them to the vet. There they are spayed or neutered. To mark that the cat is sterile a portion of an ear is cut off. This is a nationwide sign to animal control authorities and to animal rescue groups. That evening the cats are released at the same location where they were trapped from.
Average lifespan of a feral cat is 7 years. Between the hard lifestyle, predators, and lack of medical care that's what your going to get. Fluffy at home can easily double that. In doing a TNR to a feral colony you will see a reduction of the colony size in less than 6 months. Give it a couple years and you're down to a fraction of what it was before.
I've been on several TNR expeditons. (Great way to meet chicks by the way.) We have a relationship with LSU veterinary where when the students are at the point of doing their first surgeries we do the trapping. All the practice patients are ferals. Students get to practice the veterinary art, we get free spay/neuters. Win all around.
Plug yourself into the local rescue groups for more information on TNR.