Brian D. Gerber, Mevin B. Hooten, Christopher P. Peck, Mindy B. Rice, James H. Gammonley, Anthony D. Apa , and Amy J. Davis
Animals that routinely use the same areas year after year are said to have site fidelity. It is not always clear why some individuals or species have site fidelity, while others do not. Individual birds may nest near last year’s nest location if they were previously successful at hatching chicks. Conversely, they may nest far away from last year’s nest if they had failed to produce chicks. This is known as using ‘private information’ to select breeding sites. The benefits of site fidelity and private information depend on how resources necessary to survive and reproduce vary over space and time and whether they are predictable by the individual. For example, if there are large changes in the quality of nest sites from year-to-year, deciding to nest near your previous nest based on producing chicks in the previous year is entirely unhelpful. However, if there aren’t large changes in nest quality from year-to-year and nesting was unsuccessful last year, how far should you decide to move? This depends on whether there is spatial variability in resources that could provide benefits to moving, but also whether there are costs to leaving a familiar area. We integrate movement and demographic data on the threatened Gunnison sage-grouse (Centrocercus minimus) along with environmental variability to understand the adaptive selection of their site fidelity patterns. First, we found that Gunnison sage-grouse have strong site fidelity to nesting, breeding, and brooding areas, regardless of whether they produce chicks or not. Second, we found little evidence to suggest moving has any demographic benefits. Conversely, there are known costs to moving, including the loss of site familiarity and risk of predation. In fact, we suggest that across a largely intact sage-brush community, predation is the ‘great equalizer’ that has shaped the Gunnison sage-grouse’s ‘Always Stay’ site fidelity strategy. Understanding site fidelity patterns and the processes that may have led to them can help us better understand habitat selection and future spatial and population dynamics, including potential anthropogenic impacts.