No matter how you do the math, there are too many cats/kittens and too few homes. This calculator attempts to (loosely) apply math calculations to scientific principles as they relate to cat reproduction. Taken into consideration are factors such as a high percentage of owned cats are neutered and a small percentage of feral cats are neutered. Also factored in are annual mortality rates as well as post-weaning survival rates of kittens.
At seven years, the calculator shows 2905 kittens at 7 years (versus 420,000) and 49,000 at 10 years. But no rationale person would think that 2905 kittens produced by one cat and her offspring in 7 years is acceptable. Responsible pet owners should spay or neuter their pets.
Factors:
The average mature cat can have 3 litters with a total of 12 kittens per year; 10.2 surviving kittens of which 4.7 are female
The average litter size is 4 kittens with 15% loss before reaching weaning age (3.4 kittens per litter)
Gender ratio per litter averages of males to females is roughly 46.5% female (of 3.4 kittens = 1.8 males and 1.6 females)
35% spay ratio allowance for offspring (unscientific factor balancing owned and stray cats)
20% annual mortality ratio
Not factored into this equation:
An immature cat’s first litter usually consists of 2 kittens versus 4.
Unspayed female cats can begin reproducing at 6 months of age and can produce a litter during the same year of birth.
30% feral mortality
http://www.animalsandsociety.org/ass...4jaws07041.pdf
http://catvet.homestead.com/devon_re...t_1st_year.doc
http://la.rsmjournals.com/content/4/1/99.full.pdf
http://www.royalcanin.us/library/catlittersize.aspx