I stand firmly on my previous post because it covers what everybody, to one degree, agrees with. That is: Diversity is good so long as it provides areas in pasture land or cropland for good tall grass.
But let's make sure we are all talking the same language here:
Here's my language: I am talking about restoring and maintaining bird numbers to where they were in the 40's, 50's and 60's. Within 85% of those record numbers in ALL of historical "western pheasantland". Forget about the eastern states - too far gone to rescue.
Your language: Pheasants can survive in downtown Detoit and in other rather isolated areas AND in relatively thinner #'s in the grazed praire land. Yes, sufficient in numbers for the 5-20% of hunters who are hard-core, diehard bird hunters. Damn, we'll find some birds, no doubt. AND "some really good pockets here and there". And they will have weed seeds in their crops. But I am confident that grazed praire land, on average, cannot support the large bird numbers that most of us are accustomed to. Adequate numbers for some of us though, for sure. Just not on the level of the "heyday". Simply will not happen.
But let's face facts: With the exception of SD in the mid-late 2000's(mostly because of the rise in CRP), pheasant numbers are in a long-term decline throughout most of their historical range. Iowa is just the biggest example. There are MANY other ones like eastern Nebraska, SW Minnesota. etc.
When we were "experimenting" with pheasant releases in our country, many places were tried. We finally hit the "jackpot" in the Willemette Valley of Oregon. This area was a fertile but relatively ragged and inneficiently farmed area. Lots of tall grass around. Pheasant numbers literally EXPLODED in this environment. Ah-ha, we've cracked the code! We've "dialed it in".
Pheasants in their native Asian range do not exist in numbers anywhere near what we have in SD. They exist in rather thin numbers as I have heard. Might, of course, be exceptions. What we did was find a "turbo-charged" environment in Oregon and eventually in other farmland with lots of grass. And I will say, maybe we are spoiled. Maybe we should do nothing and let the slide continue to a point where they are almost like sage grouse. 1 or 2 taken per year by the last true diehards.
There is almost a direct correlation between the amount of CRP type grass(whether in the praire or cropland) and the number of pheasants. It's almost spot-on!
So I stand on my point: We must have CRP type grass as a part of a diversified mix in either cropland or praireland. I will argue, however, that pheasants will be "turbo-charged" best in cropland.