Vacuum effect of removing cats

Special to the Tribune

Often when people resort to bringing free-roaming cats to Contra Costa Animal Services, it’s because they are just fed up with the problem. We get it! But there are many reasons why trapping and removing these cats is not the solution, whether with the intent of having them killed, rehoming or relocating them. One of those reasons is what’s known in the scientific community as the “vacuum effect.”

For decades, euthanizing free-roaming cats has been the poorly considered solution to cat overpopulation. But for decades, Contra Costa County has simply been killing hundreds of healthy cats year after year and the geographic area where these cats came from still has a cat problem. Why?

When a colony of free-roaming cats is removed from a location but the food source and shelter remain, it creates a vacuum. Soon, other cats from outlying areas enter the region to take advantage of the available resources. If these cats are intact, the colony will multiply to the level supported by the food and shelter available. Trapping and removing simply draws the community into a costly, endless cycle of trapping and killing, as well as a useless waste of taxpayer dollars to house and then kill those healthy animals.

Instead, if those healthy free-roaming cats are trapped, neutered and returned (TNRd) to their home territory, they will protect their resources from other cats. We know that this works because cats are territorial. We also know that sometimes, new cats enter a colony and that the best way to deter this is to feed just enough food to sustain the cats in the colony and to limit the time period that food is available.

Think about the environment where you live and you may begin to come up with reasons why free-roaming cats are attracted to your neighborhood. Do you live by a school? Schools are infamous for having lots of food and shelter available. Do you live by a park? Parks also have lots of food and places to shelter. Are you or others in your neighborhood feeding their owned indoor/outdoor cats in your neighborhood? If so, that food is a draw for free-roaming cats.

So instead of trying to remove the cats from your neighborhood, trap them. Get them fixed and vaccinated and return them to where you trapped them. You can peacefully co-exist with the free-roaming cats in your neighborhood without having them killed.

Outcast Cat Help
(925) 231-0639

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  1. I’d be willing to peacefully coexist with feral cats if the nasty buggers didn’t mark their territory by spraying on the house — especially right by the front door! I’ve had it with scrubbing the walls and I’ve tried every type of cleaner and “keep away” chemical known to man. Please don’t say that neutered cats do not spray, because they darned sure do! BTW, there is no resident cat for them to compete with and no food of any kind outside. Any suggestions?

  2. Hi Eve,

    I’m sorry that some impolite male(s) are marking your front door as their territory! Neutering him/them is the single act that may resolve your problem. Even if it doesn’t stop the marking, it will change the chemical makeup of the urine. Without the presence of testosterone it will be far less pungent. Keep looking, there must be something attracting the cat(s) to your area. Perhaps an intact female. Hope that this helps!

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