Dec 13, 2010

Temperature Mediated Moose Survival in Northeastern Minnesota

by
Lenarz, Mark S., Nelson, Michael E., Schrage, Michael W., Edwards, Andrew J.
,
The Journal of Wildlife Management
  • States Northern Minnesota represents the southern edge to the circumpolar distribution of moose (Alces alces), a species intolerant of heat
  • States moose increase their metabolic rate to regulate their core body temperature as temperatures rise
  • Hypothesizes that moose survival rates would be a function of the frequency and magnitude that ambient temperatures exceeded the upper critical temperature of moose
  • Compares annual and seasonal moose survival in northeastern Minnesota between 2002 and 2008 with a temperature metric
  • Finds that models based on January temperatures above the critical threshold were inversely correlated with subsequent survival and explained >78% of variability in spring, fall, and annual survival
  • Finds models based on late-spring temperatures also explained a high proportion of survival during the subsequent fall
  • A model based on warm-season temperatures was important in explaining survival during the subsequent winter
  • Analysis suggests that temperatures may have a cumulative influence on survival
  • Researchers expect that continuation or acceleration of current climate trends will result in decreased survival, a decrease in moose density, and ultimately, a retreat of moose northward from their current distribution