Instructor recognized for his 40 years of research in Yukon

Yukon College biology instructor, Dave Mossop, has been recognized for his contribution and commitment to northern research. Mossop was invited to present and publish his work on Gyrfalcons and Ptarmigan at a conference held by the "World Centre for Birds of Prey" last month. This research suggests a faltering of Ptarmigan population cycles possibly related to a changing climate.

Dave Mossop has dedicated the past 40 years to understanding the relationship between Willow Ptarmigan and its predator, the Gyrfalcon. With the earliest most comprehensive research on these two populations, Mossop and his colleague, Norm Barichello, have uncovered some groundbreaking results.

The 10 year cycle of the boreal forest has been recognized for the past century and the same cycle has been monitored in Ptarmigan for the past four decades. “In 40 years, the Ptarmigan cycle has been consistent and predictable until recently”, said Dave Mossop. “The Willow Ptarmigan population seems to have stopped cycling, disrupting this normally predictable and important protein ‘rush’.

“The Ptarmigan numbers suggest that we have lost the last cycle and when their population numbers should be increasing, they are decreasing”, said Mossop. This research also suggests that the Gyrfalcon controls its population depending on the numbers of Ptarmigan. It is predicted that the decline in Ptarmigan will create a decline in Gyrfalcons as well. These ‘top predators’ are apparently now breeding too late in the year and seem to be producing fewer young.

Scientists attending the conference, "Gyrfalcons and Ptarmigans in a changing world", were both interested and concerned with the results of these findings. A similar pattern is being seen in Europe with a disruption in the grouse population cycles.