We are happy to report that CALICO has spayed/neutered  over 2,400 cats since the forming of our group.  This may seem like a small number, however, * taking the mortality into account, along with birth and death rates, the average stray female will have 5.25 litters in her lifetime, encompassing 22.3 kittens. At age two months there should be 12.9 survivors, roughly six females and seven males (at maturity, roughly 2/3 of the stray cat population is male), due to the high mortality of females during first pregnancy and birth, which will decrease to four females over time. These six females will go on to have their 22 surviving kittens each. Realistically, over 12 years, one unspayed female, with all her unspayed female offspring, reasonably can be expected to be responsible for over 3200 kittens if there is no human intervention. * Source: http://www.feralcat.com/feral-tr.html