Overwinter Survival Rate of Moose (Alces Alces) Calves in Relation to Habitat Composition
Author: Bridget Re
Major: Fisheries & Conservation Biology
Graduation Year: 2019
Thesis Advisor: Sabrina Morano
Description of Publication: Naturally occurring resource scarcity and limited foraging in winter habitats of northern New England moose (Alces alces) calves result in an energetic strain—particularly for individuals experiencing winter tick (Dermacentor albipictus) parasitism. Recent collaborative studies conducted between Maine’s Department of Inland Fisheries and Wildlife (MIFW) and the University of New Hampshire have attributed the decline of winter survival in moose (Alces alces) calves to be closely linked to winter tick (Dermacentor albipictus) parasitism (Jones et al 2018, Ellingwood et al. 2018, Healy et al. 2018, Pekins 2018). In addition to winter tick abundance on individuals, we analyzed how winter habitat composition along with other environmental and biological factors impact survival in two climatically distinct regions in Maine. Of the measured parameters, the western moose population had a more significance response in survival than the northern population, which appeared to be less sensitive to the parameters. Survival in the western population was negatively correlated with winter tick abundance (β = -0.130, 95% CI: -0.206 – -0.054) and percent of open habitat (β = -9.273, 95% CI: -14.954 – -3.593), and positively correlated with average snowfall (β = 15.705, 95% CI: 7.644 – 23.766) and capture weight (β = 0.032, 95% CI: 0.013 – 0.051). Model selection results suggest an influence of sex, capture weight, winter tick abundance, average snowfall and percent of deciduous forest within winter home ranges on survival in the northern population. However, there was high variance associated with parameter estimates, making it difficult to precisely identify the covariate effects. This suggests that there may be a more complex dynamic occurring the northern region that we were unable to detect, given the suite of variables we measured.
Location of Publication:
URL to Thesis: https://digitalcommons.library.umaine.edu/honors/546/