Long-term monitoring of lemming abundance and reproductive activity on Bylot Island, Nunavut

Lemmings are an important tundra species on which many birds of prey, foxes and weasels depend for survival. Lemming abundance is cyclic (3-4 years), but cycles have been disrupted in some areas (e.g. Scandinavia), possibly due to changes in snow cover triggered by climate change. Periodic high abundance of lemmings is essential to ensure good reproductive success of their predators and for the long-term persistence of their populations. Collapse of lemming populations could have major effects on tundra ecosystems, including specialist predators like raptors and arctic foxes, thereby indirectly affecting species of high value for Northerners. Very little is known regarding lemming populations in Arctic Canada. Most populations are thought to be cyclic, though not all of them. There is also a dearth of information regarding possible temporal changes in lemming population dynamics in Canada compared to the information available in Northern Europe.