Interesting that they are considered one of the main reasons the wild population of pheasants has gone down:
https://www.pheasantsforever.org/getdoc/bef628f7-35d2-4b82-bac4-2d68d7bffc75/Pennsylvania.aspx
PENNSYLVANIA—MOST WILD BIRDS OFF LIMITS FOR NOW
Forecast: Pennsylvania’s few wild pheasants live mostly in the state’s four active Wild Pheasant Recovery Areas, where hunting is closed—at least for now. There’s a small chance of finding wild pheasants in agricultural areas elsewhere. But most pheasant hunting this year will be for stocked, pen-raised birds, says Ian Gregg, game management division chief for the Pennsylvania Game Commission. It wasn’t always so. Breeding Bird Survey data from routes run in primary pheasant range counties in southeastern Pennsylvania show that pheasant numbers increased an average 3 percent per year from 1966 to 1974. The population held steady through 1980. But then it plunged. The roadside index fell from 32 birds per route in 1966 to less than a single bird in 2005. According to the Northeast Upland Game Bird Technical Committee report for 2015, “Loss of farmland habitat and intensification of agricultural practices on remaining cropland acres are the primary causes for these declines. In addition, the release of large numbers of game farm pheasants is thought to have greatly reduced the gene pool and survivorship of pheasants in the wild.” The Pennsylvania Ring-necked Pheasant Management Plan 2008–2017, completed in 2009, laid out a two-pronged approach to pheasant recovery. First is restoring wild birds in designated recovery areas. Second is providing put-and-take hunting.
https://www.pennlive.com/life/2022/10/why-am-i-seeing-pheasants-in-pennsylvania-again.html
A big part of the decline of pheasants in Pennsylvania has been loss of farmland, which dropped from nearly 8.2 million acres in 1974 to about 7.6 million acres in 2017.
In addition, according to the commission, “economic trends in agriculture intensified farming practices, herbicides, pesticides, chemical fertilizers increased substantially in use. Increased row crop acreage, urban developments, and the elimination of fencerows on agricultural lands also are thought to have accelerated the decline in pheasant populations.”
And two hard winters in 1977 and 1978 further depressed pheasant populations. The commission attempted to offset declining populations by mass producing and releasing more pheasants, but it soon became apparent that that only resulted in a bird of reduced quality, with a loss of hardiness and increased tameness.
Early snowfall disrupts pheasant stocking by Pa. Game Commission
Partly in response to declining pheasant numbers and places to hunt pheasants, but also as part of overall declines in participation in hunting, the number of hunters has fallen from a peak high of more than 700,000 in 1971 to about 65,000 to 75,000 in the past few years.