How many cats you'd have if you had 1 female and left it with males for 5 years

Completely inaccurate, at least for where I live. If it were true, the world would be a much less sad place. But reality cares not for cute kittens.

Here in the northeast US, feral cats (or even indoor cats with a comfy life) will never have two litters in a year. You are guaranteed one per year though. Maybe in Florida things are different.

Most kittens will never survive. We "had" one very feral cat. She would not even touch food we left out, until she was 20 years old and had cataracts in both eyes. Her secret to a long life? Dump all the kittens. Don't even let them nurse if you can help it. She had a dozen litters over the years. Most all died within two months, the lucky few lasted six. We buried all the ones we could find. Only one kitten of all her litters made it past a year.

The half life of a feral kitten is around three months. With a typical litter of five (including the runt who will get abandoned at a few weeks), maybe one will make it past a year. If no one starts feeding the extra cat, it won't even make it that long.

Edit: One final note. The life span and litter size of cats is very close to that of squirrels. True, squirrels have less environmental impact, being herbivores. (But this just means an environment could support an even larger number of squirrels.) The world is not drowning in squirrels (except for maybe Cornell) despite no one ever fixing the squirrels on their property.

Right, so cats are close to an r-selection strategy:

http://en.wikipedia.org/wiki/R/K_selection_theory

If you were to do the same calculation with fruit flies, or even bacteria, you'd probably reach the number of atoms in the universe (~ 10^80) in less than five years. For various reasons, the exponential will turn into a logistic curve pretty soon (unstated assumptions of the article include the availability of food, water, space and the absence of predators).

Source code would be cool. With some tweeking you could edit the source for other animals. Is there any other stats formula out there that does this kind of thing?

Of course the biggest shortcoming of all is that breeding will quickly outpace the food supply and many cats will starve to death or die of other causes without having reproduced.

There was an article about this in sfgate two weeks ago.

It's pretty much a fantasy, madeup statistic.

http://www.sfgate.com/columns/yourwholepet/

If the entire cat population after five years originated from one female I think the total would be somewhat less than that estimated due to negative genetic effects - mainly inbreeding depression: http://en.wikipedia.org/wiki/Inbreeding_depression.

Thing is this: 1) not all survive out of a litter, even after several weeks, 2) if a cat has litters too close together, she will often refuse to nurse the second litter and they will all die. If everything that gave birth by litter survived, we humans wouldn't be here.

It is possible to have dozens or more, since the female cat can have a litter from multiple sires. A female cat can mate with multiple tom's during the estrus (7-21 days) or heat cycle.

I don't understand why it took over 3 hours to simulate 1000 iterations, I'm sure this could be done much more quickly, even with perl.

Wish the author would post source code.

Next month -- October 16 -- is National Feral Cat Day:

http://www.alleycat.org/NetCommunity/Page.aspx?pid=388

(If you feed strays without also pursuing trap/neuter/release you may be just multiplying the misery.)

neat experiment! lol