There IS scientific evidence that the further north a population of a species lives the larger the body mass they carry. It's called Bergmann's Rule. So, MN whitetails are larger than Texas deer but smaller than Norther MB whitetails.
Possible you got into a more southern breeding population that you don't shoot here in MN~ they fly right over us. But the birds you shoot up on the Range make a stop.
So, in MN your shooting Hudson Bay birds. In TX you're shooting Lake Eerie birds.
I recommend taking your "Lesser Lesser" theory to the MN DNR, they'll have the answer