TNVR and colony management is, in my opinion, one half of the vital job of dealing with feral cats, with the other half being enforced cat leash laws.

TNVR is Trap-Neuter-Vaccinate-Release, which, along with colony management, sets up a situation where you have a small group of non-breeding, non-fighting, non-diseased cats that you feed, which then prevent other groups of breeding/fighting/eating other animals cats from moving into the area.

http://www.straypetadvocacy.org/html/predation_studies_reviewed.html
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=16603400&dopt=Citation
http://www.feralcatfocus.com/Eradication_/eradication_.html -- this is the most straight forward one.

As was pointed out in the first link, the predation style of cats is far better for small mammals than it is for birds.