I currently live in southeast New Hampshire and was reading a history of my town and it describes the landscape as having a lot of quail and even partridges. The book said children going to school around 1920 would see lots of quail. The town itself has not changed much from 1920 except that there are fewer farms. The population is about the same. In fact, the population is probably lower now than it was in 1920.
I have never seen a single quail here, and certainly never seen a partridge. I have seen a pheasant on rare occasion. There are a lot of turkeys.
Is this like a Silent Spring thing, they all got killed off by DDT or something? Or is it because of insecticides killing all the crickets, maybe? I almost never hear crickets at night.