7 ms·

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

20 points by slater 16y ago

trouble 16y ago
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 http://en.wikipedia.org/wiki/Inbreeding_depression.
naelshawwa 16y ago
neat experiment! lol
deleted 16y ago
[deleted]
houseabsolute 16y ago
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.
- pavel_lishin 16y ago
  Realistically, sure, but if someone were really determined to carry this out in real life - let's say, the government of Thailand for no real reason - they'd be able to afford to feed 10,000 cats pretty easily. Oh, and what if we assume that the cats can or will eat each other, or corpses of other cats?
  - eavc 16y ago
    Feeding 10,000 cats--not that hard. Getting 10,000 cats to breed optimally--pretty much impossible. Heck, try getting three of them to optimally not fight each other for a week at a time.
    - absconditus 16y ago
      This is your man: http://www.youtube.com/watch?v=6VswBKrPuAQ http://www.youtube.com/watch?v=6VswBKrPuAQ
f1gm3nt 16y ago
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?
- farmerbuzz 16y ago
  Differential equations are great for modeling these sorts of problems. http://www.geom.uiuc.edu/education/calc-init/population/ http://www.geom.uiuc.edu/education/calc-init/population/
mikecane 16y ago
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.
zeteo 16y ago
Right, so cats are close to an r-selection strategy: http://en.wikipedia.org/wiki/R/K_selection_theory 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).
malabar 16y ago
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.
keenerd 16y ago
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.
zepolen 16y ago
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.
Empedocles99 16y ago
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/ http://www.sfgate.com/columns/yourwholepet/
gojomo 16y ago
Next month -- October 16 -- is National Feral Cat Day: http://www.alleycat.org/NetCommunity/Page.aspx?pid=388 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.)

20 points by slater 16y ago

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 http://en.wikipedia.org/wiki/Inbreeding_depression.

naelshawwa 16y ago

neat experiment! lol

deleted 16y ago

[deleted]

houseabsolute 16y ago

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.

pavel_lishin 16y ago
Realistically, sure, but if someone were really determined to carry this out in real life - let's say, the government of Thailand for no real reason - they'd be able to afford to feed 10,000 cats pretty easily. Oh, and what if we assume that the cats can or will eat each other, or corpses of other cats?
- eavc 16y ago
  Feeding 10,000 cats--not that hard. Getting 10,000 cats to breed optimally--pretty much impossible. Heck, try getting three of them to optimally not fight each other for a week at a time.
  - absconditus 16y ago
    This is your man: http://www.youtube.com/watch?v=6VswBKrPuAQ http://www.youtube.com/watch?v=6VswBKrPuAQ

f1gm3nt 16y ago

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?

farmerbuzz 16y ago
Differential equations are great for modeling these sorts of problems. http://www.geom.uiuc.edu/education/calc-init/population/ http://www.geom.uiuc.edu/education/calc-init/population/

mikecane 16y ago

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.

zeteo 16y ago

Right, so cats are close to an r-selection strategy: http://en.wikipedia.org/wiki/R/K_selection_theory 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).

malabar 16y ago

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.

keenerd 16y ago

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.

zepolen 16y ago

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.

Empedocles99 16y ago

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

gojomo 16y ago

Next month -- October 16 -- is National Feral Cat Day: http://www.alleycat.org/NetCommunity/Page.aspx?pid=388 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.)