Feral Cat Behavior -
Cat Over-Population
and
Feral Colony Density

By Jack Carter

The Race To Outpace Feral Cat Over-population -- a symposium presentation by Linda Kelson, Feral Cat Coalition Board Member states that: "The HSUS estimates that a pair of breeding cats and their offspring can exponentially produce over 400,000 cats in 7 years."

What are the REAL numbers, though? How many kittens are typically born in each litter? How many of the female kittens survive to have a litter, themselves? How long does an unspayed female survive "in the wild"?

Good questions...I've seen the usual numbers printed also (the 400,000 to 10 million) and you are correct...this just doesn't happen...if it did, well, the world would be full of cats and there'd be little room for us humans.

The truth of the matter is that, within a true true feral population, the birth rate is quite low, and tied to many different things, such as food availability, predator status, general genetic health of the core population, climate and just plan good/bad luck!

I'll speak of non-supported colonies, as the introduction of human care takers places its own variability upon the colony population, raising it many times higher than when a human care-taker is not present.

From my work, I have found that a colony often stabilizes at a certain size dependant upon two primary criteria...food availability and presence of human population. In areas of high human presence (but LACK of a human care-taker) the colony size generally is lower than in areas of low human population...it seems that humans bring their own problems into feral colonies...often to the bad...I generally count them in the "predator" status, even though we do not "hunt" cats, per se, as you would think when we speak of "predator". The encroachment of human population brings about not only the "cat killing" and abuse (which is often higher than we would like to see) but also side problems such as pollution; even such issues as mouse and rat control bleeds over into the local feral cat population as these "baited" mice and rats tend to take the poisons into the colony, killing or seriously decreasing the cat population.

In most true feral colonies (and I'm speaking in general terms --sort of a of "rounded" average) the population stabilizes and new kittens that live to the one year mark (sort of a gauge of whether they will live a full life of not) typically works out to about one or two per breeding mother...quite a bit lower than the 400,000 to x-millions we read about.

From my work, a feral population generally stabilizes at about 20 to 30 cats per colony, with a colony roughly every 1 to 5 acres of workable colony space. This is based upon a good food supply, low-to-average predator count, and a wild living climate. Now, this also doesn't take into account disease, which also takes its share, and often I've seen whole (or nearly the whole) colony taken out by a bad URI --this is generally what I call a "restarting" point in the colony-- the majority of the colony will die out, leaving a hardy few, and the whole process starts all over again; this is why I say that the population reaches stability. While the potential of large colonies exist, generally once they get to a certain size, bamm! a bad disease takes the number back down again.

The main problem I see isn't one of feral colony population, but rather one of human/cat. From what I've seen the problems start when we don't alter our animals for one reason or the other. A normal house cat has a much greater chance of its total litter surviving, something I seldom see in the wild with ferals. As I have stated, on or two survivors is typically about all that you see without a care taker, but when a "house" cat has a litter, its general overall good health, lack of predators, and vet care goes into seeing that the whole litter generally makes it. That is where the problem comes in. As more and more shelters go "no-kill" the option of placement into homes for these cats lessens as these no-kill shelters often fill up with cats that are not able to be placed for one reason or the other (generally age...everyone wants a baby, no one wants an older cat) so owners more and more resort to dumping...and this is where the feral population increases the most...the introduction of tame and nearly tame house cats into an area where ferals have been spotted (typically I hear, "Hey...I saw a group of cats in this field, so I figured that these would survive better here than anywhere else". I have been told this when I have caught people dumping cats into my feral colonies...)

So we see that the problem is a human one (often people don't spay or alter their cats so that their kids can see the "miracle of birth" truly--I hear it all the time!) so education is key --if people were to see the things I have seen; if they were to hold the tiny kittens as they struggled to survive and watch helplessly as they gasped their last breath, maybe it might help... As I've said, some of the saddest times in my life have been these. I still remember one tiny kitten from a wild mother that had never allowed me to get close to her young --one cold raining night while hiding in the bushes watching her, she brings this tiny white kitten close to me-- I was able to slowly walk up to it, and low and behold was able to reach out and pick it up...I was totally amazed...but not for long. The little white kitten was weak and dehydrated; upon bringing it inside (I seldom do that: I try to let nature take its course, but sometimes my heart is bigger than my notion of letting nature work things out) I notice a wound in its shoulder...upon closer examination, I saw that a fly larva had burrowed into its skin and was growing --making a bigger and bigger wound. I was able to extract the larva, but the kitten died a few hours later --there was nothing I (or anyone else) would have been able to do to help it; it was just too far gone. It's things like this that if people could see, might just shock them into thinking more carefully the next time they wanted their child to see this "miracle of birth" for what it really is: A tragedy of death and pain.

Well...maybe not earth shattering information, but it may answer a question or two about your cats!

Jack Carter

This article originally appeared on the Feral Cat Rescue mailing list: Rescue Cat (21 April '98)
It is reprinted here with the author's permission. Contact Jack Carter at: jcart@austin.ibm.com

Why Do Cats Sniff Butts?

The Day in a Feral Cat's Life

Stalking a Mouse . . .

Territorial Marking

Amby's FERAL
CAT PAGE

Amby Duncan-Carr

Amby's CAT
INFO SITE

Amby's Feral Cat Site LOGO GIF
courtesy of:
Cindy's Free Cat Graphics

URL of this page:
http://amby.com/cat_site/carter_5.html

Feral Cat Behavior - Cat Over-Population and Feral Colony Density

By Jack Carter

Feral Cat Behavior -
Cat Over-Population
and
Feral Colony Density