Year of Award

2010

Document Type

Thesis

Degree Type

Master of Science (MS)

Degree Name

Wildlife Biology

Department or School/College

College of Forestry and Conservation

Committee Chair

Mark Hebblwhite

Commitee Members

Joel Berger, Marco Musiani, Paul R. Krausman

Keywords

Distance sampling, Moose, Resource selection, Spatial separation hypothesis, Woodland caribou

Publisher

University of Montana

Abstract

Woodland caribou (Rangifer tarandus caribou) are threatened across Canada due to human disturbance altering predator-prey dynamics. The niche specialization of caribou enables them to survive in nutrient-poor habitats spatially separated from other ungulates and their shared predators. The conversion of old-growth forests to young seral stands is hypothesized to increase the abundance of moose (Alces alces), the dominant prey for wolves (Canis lupus), resulting in apparent competition. We first examined habitat selection of moose in 2 regions with differing intensities of human disturbance in west-central Alberta and east-central British Columbia to assess how human disturbance affects the spatial separation of moose and caribou. We built resource selection functions with data from global positioning system (GPS) collars deployed on 17 moose (8 in a region with high and 9 in a region with low human disturbance) at 2 spatial scales. Our results indicated that moose in our study area make forage-risk tradeoffs in a hierarchical fashion similar to caribou, potentially eroding spatial separation in human disturbed landscapes. We also evaluated the spatial partitioning of resources by comparing resource use with GPS locations from 17 moose and 17 paired caribou using logistic regression. As expected, human disturbance decreased the resource partitioning between moose and caribou. Thus, systematic moose management and monitoring will be essential for caribou conservation. Currently, a Stratified Random Block (SRB) survey design is widely used to estimate moose populations, but these surveys are expensive and often result in imprecise population estimates when not corrected for sightability bias. We evaluated the application of distance sampling as an alternative to SRB surveys, especially for use in caribou ranges. To correct for moose missed on the transect line, where a detection rate of 100% is critical, we developed a sightability model using 21 radio-collared moose. After correcting for sightability, distance sampling was more precise and efficient than SRB surveys. In this way, more efficient distance sampling methodology can be an important tool for caribou conservation. Combined, our results showed the importance of moose management in caribou ranges due to decreased spatial separation between both ungulate species in disturbed landscapes.

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© Copyright 2010 Wibke Peters