Over 80 million pet cats reside in U.S. homes, and as many as 80 million more free-roaming cats survive outside. How to deal with this feline explosion has caused much debate, especially between cat lovers and wildlife advocates who are concerned that cats are regularly killing birds and other animal species.
Using a computer model, the researchers found that colonies of feral cats that were trapped, given vasectomies or hysterectomies, and released (TVHR) shrank faster than colonies that were trapped, neutered, and released (TNR), a method of feral cat control promoted by many cat advocates.
Feral cats live in groups that are controlled by a dominant male. A vasectomy cuts the tube that carries sperm without removing a cat's testicles, so a vasectomized cat retains its sexual hormones. Thus, it can also keep its dominant position in the colony, so it's able to mate with females without producing kittens.
On the other hand, neutered or castrated—and thus sexually inactive—cats returned to a colony lose their position to the next most dominant breeding male.
What's more, when a non-sterilized female cat mates with a vasectomized male, she undergoes a 45-day pseudo-pregnancy period, further reducing opportunities for reproduction, the study authors found.
The new study "looks like good science—it's kind of provocative," said John Hadidian, senior scientist for wildlife at the Humane Society of the United States.
"It has something more to add to this very controversial issue, which is what we're looking for: new ideas and new strategies."( Rest under the cut...Collapse )