Is anyone going to mention the million upon million of antelope that disappeared?
There were plagues of Rocky Mountain Locust in the 1800's swarms estimated to be hundreds of miles long and many miles wide they just never returned no one knows why,
Jack rabbits in the NW have become scarce it is even rare to see one where 40 years ago there were millions
I use to shoot lots of pheasant's around this area now it's rare to see a nice cock,
When I was a kid there were bullfrogs everywhere I have not heard one in over a year
there were lots of leopard frogs too now if you ask someone that grew up here 40 or less they don't know what a leopard frog is.
ten years ago we would shoot hundreds of whistle pigs a day, two years ago I spent about a hour in the same locals and shot at two, and didn't bother to even go last year.
On and on and so forth, the bottom line is,
Critters come and go for multitude of reasons many of which we don't really know why.