420,000 Kittens? The Unspayed Cat To Kitten Calculator


420,000 Kittens? The Unspayed Cat To Kitten Calculator

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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

    • "; echo ""; //each cat will have 4.7 female kittens for ($i = 1; $i <= 11000; $i += ($i * 4.7)) { $plural = ""; if ($i > 1) { $plural = "s"; //reduce for mortality and spay $c = $i; //total live female cats $d = $i * .20; //percent died $s = $i * .35; //percent spayed $i = $i * .45; //remaining live female cats } $b = $a += 1; echo ""; } echo ""; echo "
    YearFemale CatsMinus Died1
    (@ 20% mortality)    		Minus Spayed2
    (@ 35% spayed)    		Breeding Female Cats# Kittens Born# Surviving Post Weaning3Surviving Female Kittens4
    Year " . round($b) . "" . round(@$c) . " - " . round(@$d) . " - " . round(@$s) . "" . round($i) . " female cat" . $plural . " will have " . round($i * 12) . " kittens " . round($i * 12 * .85) . " will survive and " . round(($i * 12 * .85) * .465) . " will be females
    1http://www.animalsandsociety.org/assets/library/199_s15327604jaws07041.pdf
    2http://catvet.homestead.com/devon_rex_project_report_1st_year.doc
    3http://la.rsmjournals.com/content/4/1/99.full.pdf
    4http://www.royalcanin.us/library/catlittersize.aspx
    "; print "
    "; //for ($i=1, $k=10; $i<=10 ; $i++, $k++) { // echo "Var " . $i . " is " . $k . "
    "; //} ?>