Reading the New York Times front-page story about Colombia’s fight over a planned hippo cull, it was shocking to learn that dozens of the hundreds of hippos “were castrated to keep them from reproducing, a grueling six-to-eight hour nighttime undertaking.” The efforts were as predictably expensive, painful, and futile as attempts to curtail pet overpopulation by neutering males. They don’t work well unless you can alter every male in the population.
Here’s the math: let’s say you have a herd or pack of 20 animals, 10 males and 10 females. You don’t manage to spay all of the females, but you spay 9 of the 10 of them, while castrating or neutering none of the males. How many calves from hippos or litters from dogs do you get that season? One, from a truly exhausted female.
Now let’s say you decide to neuter males, and you manage to corral and neuter 9 out of the 10 while spaying no females. How many calves or litters do you have in that herd or pack that season? Ten, probably, and one very proud papa.
Neither hippos nor dogs are monogamous. Population growth is determined by the number of fertile females.
That’s why it’s frustrating to read of efforts to curtail populations that focus on castrating or neutering males, whether they be hippos in Colombia or neighborhood dogs elsewhere, with killing as the fallback when those efforts fail. To be successful, resources and energy must be spent on spay.
Wow. Now there's some outside-the-box thinking! That math is hard to argue with. Thank you!
Thank you, sincerely, for pointing out something so obvious that it leaves one stunned that it is even considered as a "solution".