The cause of the 11-yr cycle in Ruffed Grouse populations remains unanswered. Last research report I read showed weaknesses in Gordy Gullion's "male aspen bud theory" from the 1950's and tended toward the existence of a complex predation cycle. Maybe another hundred years of data gathering will provide the answer. While all this was happening, the RGS and state agencies have learned a lot about how to create good breeding habitat for the species. I suggest all Ruffed Grouse and Woodcock hunters join the combined RGS-American Woodcock Society now called the RGS-AWS.