Wildlife Doesn't Care About Math

Of course I am interested in the fluctuations of wildlife populations. Although math is my weak subject, I almost understand Uncle Ken's equation, but I don't understand why "x" is always less than "1". Where did that number come from?

Be that as it may, the equation seems to overlook one important factor. In addition to the rate of reproduction, we must also consider how many wildlife babies live long enough to reproduce themselves. Most birds and small mammals can reproduce when they are a year old, with deer it takes a year and a half, and I'm not sure about bears and lions. Generally, the more babies an animal has at once, the fewer of those babies survive to breeding age. Take the ruffed grouse for example. Mama grouse nests in the spring and has about a dozen babies a year. About half of those babies don't survive till fall, and about half of the remainder don't make it through the winter. That leaves three new grouse to reproduce, in addition to the two parents if they're still alive by spring. Grouse populations tend to increase for about five years and then decline for about five years.

Rabbits and hares do something similar, although their boom and bust cycles tend to be more dramatic. The snowshoe hare population in Beaglesonia reached its peak in the early 1990s, then crashed, and hasn't recovered yet. I have read that most of the Northern Lower Peninsula has experienced the same thing but, last I heard, the Upper Peninsula has not. If global warming was the cause, cottontail rabbits should have filled the void left by the vanishing snowshoe hares, but I have not heard of that happening.

I read someplace once that whitetail deer have their ability to double their population every year, but those were city deer living in unnatural conditions. (I seem to remember it was Ann Arbor.) While the average mature doe has two fawns a year, first time mothers commonly lose them both, and even experienced mothers have a hard time raising both of their fawns to breeding age.

I saw Chapter 20 of The Good Place this evening. Starting next week there will be a conflict with another show that my hypothetical wife prefers, so I will be watching it online. I saved that Couch Tuner link to my favorites list, but I haven't tried to use it yet.