Now in its 27th year, our Snowy Owl Breeding Research project is the longest running breeding study in North America. Snowy Owls did not breed in Barrow, AK in 2017, presumably because Lemming numbers were low. Population indexing is currently underway for 2018.
Snowy Owls have a circumpolar breeding distribution associated with Arctic tundra. Here they nest on the ground and are dependent on lemmings for successful breeding. However, lemming numbers fluctuate widely throughout the Arctic in location and time. Thus, in some years, some Snowy Owls may not breed. But when huge numbers of Snowy Owls migrate south into southern Canada and the northern U.S., we know they just had a terrific breeding season, as most of the owls are young of the year, perhaps 5-6 months old.
Our data challenges the long-standing view of regular, predictable lemming “cycles” at Barrow, but clearly lemming populations fluctuate over time. Because lemmings and Snowy Owls are on a downward trend in the Barrow region, our newest research examines this trend in relation to the changing climate. We are currently conducting this analysis in partnership with the Max Planck Institute of Ornithology and with funding from the Charlotte Martin Foundation.
Graph © Owl Research Institute