Long-term databases track changes in the population parameters of the top predator (gyrfalcon) and the keystone prey (willow ptarmigan).
Three study areas spaced north to south across the Yukon are surveyed annually. Breeding density and productivity are key variables along with breeding chronology. Ground search in late winter is used to survey ptarmigan, while air survey to known nest sites tracks gyrfalcon numbers.
Ongoing reports and publications cover significant details and trends. Currently evidence points to a disruption to normal population cycling, and suggests a declining overall trophic response in the system.
This project is a part of the Biodiversity Monitoring Program with the YukonU Research Centre.
Project Lead: Dave Mossop, Professor Emeritus, Yukon University
Research Support: Yukon University students
Mossop, D. H. 2011. Long-term studies of Willow Ptarmigan and Gyrfalcon in the Yukon Territory: A collapsing 10-year cycle and its apparent effect on the top predator. In R. T. Watson, T. J. Cade, M. Fuller, G. Hunt, and E. Potapov (Eds.). Gyrfalcons and Ptarmigan in a Changing World. The Peregrine Fund, Boise, Idaho, USA. http://dx.doi.org/10.4080/gpcw.2011.0206