Monitoring of Lapland longspur reproduction on Bylot Island, Nunavut, Canada

The Lapland longspur (Calcarius lapponicus) is one of the most abundant and visible terrestrial songbird breeding in the Arctic. As other Arctic-nesting birds, they are constrained by a very short time period during which they can reproduce. Though the timing of hatch is critical for the growth and survival of young, even more crucial is the ability of longspurs to ensure that their nests survive until hatch. Nest predation is an important source of mortality for this bird especially when lemming abundance is low. Longspurs eggs are an alternative prey resource for the Arctic Fox, which preys primarily on lemmings. Alternately, when lemmings are abundant, the Arctic Fox will focus on lemmings, and longspurs may experience reduced predation pressure and increased nest success.

Longspur nests are mainly found through systematic searches of a 4.5 km2 core area near our main field station from early June to early July since 1995. Nests are also found opportunistically while conducting other field activities over a larger area. Nests found are positioned with a GPS receiver and revisited during the breeding period to determine clutch size, laying and hatching dates and hatching and fledging successes. Nests found in the core area are monitored more intensely (every 2 to 6 days) while those located elsewhere are monitored less intensively.