Well I was right with this subject I am happy to say so no one should worry-where ever you might be; the same goes for you regarding x your "lack" of crow activity in old familiar haunts. I recently learned there has been no particular "decrease" of crows but rather a shift in old locations as hard as that was for me to believe as it were. Now I am not about to go into new locations of the winter roosts here....or New England area but the patterns exist where ever you are. Even though it is hard to imagine especially if your old haunt delivered generally a 50 bird kill or so each time out and now last year no crows. BobA has said it too that crows do change old haunts from time to time. Because they do. With me it was roughly every ten to twenty years or so. Totally blew my mind but crow shooting is addicting. Unfortunately others saw me doing it and it became :"Wow man-you shooting crows man? I didn't know you could do that!
If you take the occasional shooter out I guarantee he will ruin it-just a matter of time...he'll bring his buddies and you are ruined!
My point is the shift isn't terribly far away and likely more crows than my old haunt when it was good! Well so long as one of these scare crows don't mess things up. My definition of a scare crow is one who shoots out the area day in and day out and even getting too close to a roost sending the crows off to the next county or even the next state!
Likely not enough food to support the rather large number of crows is my best guess but there was enough to support migrants and then some.....still odd over all as there was food availability minus the old dumps to support some reasonable numbers or -say-50% capacity or slightly less with a mere handful of die hards for the winter; the former numbers bailing for available food sources not buried in snow......however in spring the newly arriving crows returning to their summer playgrounds and seeing no available food sources turn back with the odd "reverse" migration.....and basically trickle back is a more accurate description....
one year it was reported a large number of crows showed up in spring so that had to mean some farms were spreading manure so the melting snows would be absorbed into the now fertilized grounds....in any case my point is crows will not just starve to death but look for greener pastures so long or as long as the pastures hold up as with that huge migration in the forties{?} where hundreds of thousands of crows came to the central and southern plains creating a legend who drifted in from the northeast and challenged the massive numbers of seemingly endless crows...…!! ( I just had to say that! ) Referring to BobA……
But these crows never cease to amaze me. One never knows what they are up to but if you don't see them chances are they are they aren't terribly far away..... my experience generally has been this big flock (New Hampshire standards now not by midwestern standards) showed up one fine day remaining a week until the food supply dried up.....