That was an interesting read Native. Bell curves are always sliding as a whole to the left or right of a graph and in height , affected by the factors controlling the group. A better name than bell curve would be normal distribution but guess that is semantics.
In answer to you question, I think that is going to vary not only in areas of the country, but even in groups within miles of each other. My classic example, is that bell would be to the left of shown graft in county my farm is in. Yet just 50+ miles away, in our bow hunting only counties, that graph would sit more to the right of me, and probably skewed slightly to the right in height. So yes it varies, but the pattern would be similar anywhere especially with prey animals. I think it would be affected by population, food, predators, etc. In some areas, disease would change the shape if older age or even younger age, are affected more by that particular disease or effect. Examples would be EHD that tends to affect more mature deer, and predators that tend to affect younger deer. Interesting study.