During the past 52 years I have seen three prime areas for crows go away in 22 years. One area in 10 years and another in 16 years. The reasons vary from the feed changing from peanuts to cotton or milo to cotton. Other factors are the destruction of their roosts to make way for urban sprawl with housing.
This is why I go to different states to check out new potential areas. Most of the time it's a wild goose chase where they have crows but not enough to break in a new area because of the lack of good numbers to hunt.
Another area that I used to hunt still has crows in good numbers but you only get 3 to 4 days of hunting due to restricted land access. If I could stay for a week at least I would still drive the 640 miles one way.
I have made plans to check out a new area this fall but you never know until you get there and spend some time snooping around and talking with the locals. Another area that I used to hunt was near Miami Oklahoma. It was a good area for roughly 10 seasons. The roost was 3 miles west of the town and when you asked the locals about crows they had no clue what was going on! Getting good intel on crows is very difficult, some of the publications that talk about 100,000 crows in Wichita Kansas which is pure fiction! They did have roughly 40 to 50 thousand perhaps between 1978 to 2000 before the city harassed them and they pulled out of the entire area. Had some great shoots down there in the 5 and 600 bird range in those days. Many of those crows in Wichita came from the roost in Hutchinson where I live. They developed the roosting area with houses and that was the end of that! The crows just followed the Arkansas River from Hutchinson to Wichita and made a home in the center of Wichita for 22 years! Another roost 40 miles west of Hutchinson which was just as big as Hutchinson in the late 60's to mid 80's which held hundreds of thousands of crows in each roost. Another roost down at Harper Kansas had perhaps 35 to 40 thousand crows in past years is also a thing of the past now. I'd love to know where all those crows went!
So if you want to stay ahead of the curve don't think the crows in your area will last your whole life cause things change! Check out new areas!
What happened here was choice land was grabbed up for in one area for factories ; houses and the offspring weren't interested as farming became a hobby or was....the old timers joined God and the crows by this time left the area that and the style of "hunting" I call "scare crow"...sit out there all day in and out killing it for everybody else and another item to boot; others could see the decoys and wanted a piece of the action and eventually killed it to nothing as well...not even worth going..at this point...those old areas..by the time the roosting crows got so low eventually these die hards left the county altogether.....now I need to go an hour or so to find any numbers to shoot at....it was predictable initially but being so far from headquarters I only took "gravy" shots not knowing where the local gun store was in this area.(And still don't)...last year totally stunk as they were not there yet or as I was to learn from scouting more than likely up the road so many miles being there a "huge" (for NH now) corn field they likely took a shining to....and I like having several cornfields in the area as it will at least hold the grouping in the area for some shooting without spooking them out all at once for the day and keeping them spooked the following time period.