Historical Trends in Nest Success of Eastern Prairie Population Canada Geese: Examining the “Bird-Lemming” Hypothesis at Cape Churchill, Manitoba

canada goose nestMATTHEW E. REITER, Minnesota Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN 55108

DAVID E. ANDERSEN, U.S. Geological Survey, Minnesota Cooperative Fish and Wildlife Research Unit, University of Minnesota, St. Paul, MN 55108

Abstract

collared lemmingThe “bird-lemming” hypothesis describes the dynamic interaction of predator, prey, and alternative prey in determining reproductive success in arctic-nesting birds.  We assessed this hypothesis using data collected during annual Eastern Prairie Population (EPP) Canada goose (Branta canadensis interior) breeding ground surveys at Cape Churchill, Manitoba, and measures of relative abundance of collared lemmings (Dicrostonyx richardsoni) based on analysis of willow (Salix spp.) scar age frequency distribution.  We assessed nest success prior to and post-discovery of nests, and included the following variables in regression models of annual nest success; arctic fox (Alopex lagopus) abundance in the current and previous year, lemming abundance in the current and previous year, and nest density.

foxesWe analyzed 2 separate time periods, 1993 – 2004 and 1998 – 2004, because fox removal occurred on our study area from 1994 – 1997.  We developed models a priori and we ranked them using Akaike’s Information Criterion corrected for small sample sizes (AICc).  Our results were not consistent with predictions of the bird-lemming hypothesis, but suggested that both arctic fox trapping and nest discovery influenced predator-prey dynamics and subsequently nest success.  Our results also suggest that predators may respond more quickly and across a broader spatial scale to declines in primary prey (e.g., lemmings) than previously considered under the bird-lemming hypothesis.

Publications

Reiter, M.E. 2006. Historical trends in collared lemming abundance (Dicrostonyx richardsoni) and nest success of Eastern Prairie Population Canada geese (Branta canadensis interior) in northern Manitoba: Evaluating the “bird-lemming” hypothesis. Thesis, University of Minnesota, St. Paul, MN. 79pp.