For decades, it has been felt that the lack of observations in Alberta Saskatchwan and even Montana, North Dakota and Minnesota meant that prairie chickens were not present originally in these regions. Stuart Houston explained this by suggesting that settlers having opened the prairies allowed for prairie chickens to expand along with the settlers.
However, recent papers have explained new studies on the genetics of populations from northern parts of the Greater Prairie chickens range. it is now apparent that populations of Greater Prairie Chickens were present in these northern states all along. It is certain that the introduction of the grains allowed far greater numbers of prairie chickens to survive the harsh winters and thus the results were dramatically increased populations.
Ross shows that the expansion model, where birds would have “flown behind” settlers, was highly unlikely. Because male prairie chickens do not wander widely from natal locations this behavioral limitation also tends to question the expansion theory. That birds were present in lower numbers and thus just responded to increased food supplies is a much better model.
Our range maps have been changed slightly to reflect this new understanding. We now display the full range of the birds with population densities reflecting the original concepts. Once agriculture began to leave winter food supplies the entire population would have grown more and more dense.
As conditions deteriorated in eastern states, these states wold have gradually declined in density and the agriculture to prairie ratios became ideal to increase populations.