Trap-Neuter-Return improves the lives of feral cats, improves their relationships with the humans who live near them, and decreases the size of colonies over time. These studies have been conducted in multiple countries, and have been published in a variety of peer-reviewed scientific journals.*

Studies document that after neutering, cats become healthier and gain weight, and that the lifespan of cats in managed colonies increases. One study found that at the end of a 10-year Trap-Neuter-Return program, 83% of the cats in the managed colonies had been residing in those colonies for more than six years, resulting in a lifespan comparable with household cats, who have an average lifespan of 7.1 years. In addition, studies have found that aggressive interactions among cats in managed colonies decrease after spaying or neutering, while affectionate interactions increase. Cats in neutered colonies also roam less and do not fight over mates.

Here is a great video from Shadow Cats in Round Rock TX.  It is a Day In the Life of TNR.

Alley Cat Allies information on trapping moms and kittens together.

Understanding Why Catch and Kill Doesn't Work.

How can you tell if a cat is a Stray or a Feral?*

NOTE: It is difficult to assess cats who have been recently trapped or are otherwise stressed. It is often necessary to wait until they are placed in a less stressful situation and have a chance to calm down before their temperament and socialization can be accurately determined. Depending on the cat and the place where they are being held, this may take a few hours to days or even weeks.

*Information provided by www.alleycat.org