Movements of Blue Grouse on the Summer Range

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This study, part of a long-term research program begun in 1944 (Bendell and Elliott 1966, 1967), was done to find how Blue Grouse (Dendragapus obscuras) are spaced on the breeding range, and to relate dispersion to population regulation. In the populations studied, breeding numbers failed to increase, even though each previous autumn many more young than necessary were available to replace the relatively constant losses among adults over the winter (Zwickel and Bendell 1967). Despite fluctuating production, constant recruitment of young birds has equalled constant mortality among old birds, resulting in stable breeding populations. We do not know the mechanism which allows certain young birds to join the breeding population while the rest disappear. I studied the dispersion, movements, and behavior of Blue Grouse on the summer range to see if there was any evidence of social interaction that might affect recruitment. I concentrated on year-old birds because these are the new recruits to the population. Movements were studied over the entire six months when Blue Grouse were on the