Colorado Parks and Wildlife has conducted research to evaluate seasonal use patterns of Gunnison Sage-grouse in the past but still lacked detailed information on demographics and dispersal patterns within and among populations. Therefore, Colorado Parks and Wildlife initiated this project to determine the impact of landscape features, such as habitat fragmentation, on the movement patterns and demography of Gunnison Sage-grouse.
Researchers focused the study on two different populations: the Gunnison Basin population, which is the largest and most genetically diverse population, and one of the smaller populations that inhabits Montrose and San Miguel Counties (the San Miguel population). Using radiotelemetry, researchers tracked movements, estimated nest success and estimated survival rates of juvenile and adults. Researchers analyzed the data collected using Geographic Information System to develop movement and spatial models. Nest success did not differ between the two populations or in relation to female age, and was not strongly related to vegetation measures at nest sites. Nest success was variable among years, and nests initiated early in a season had higher success than nests initiated later in the season.
There was no juvenile recruitment into the San Miguel population during the study. Annual juvenile recruitment was variable in the Gunnison Basin and declined over the course of the study. Annual and seasonal survival of adults was variable and did not differ between the two populations or between yearlings and older adults.
During the study, the two populations were declining from recent high levels, with the San Miguel population experiencing greater declines than the Gunnison Basin population. Projections of population persistence indicated that the Gunnison Basin population is likely to persist over the long term. The results of this research will help wildlife managers evaluate the relative outcomes of alternative management actions.