Year of Award
2020
Document Type
Thesis
Degree Type
Master of Science (MS)
Degree Name
Wildlife Biology
Department or School/College
W.A. Franke College of Forestry and Conservation
Committee Chair
Joshua J. Millspaugh
Committee Co-chair
Chad J. Bishop
Commitee Members
Jeffrey M. Good
Subject Categories
Natural Resources and Conservation
Abstract
As forests across the United States have been altered due to fire suppression in the last century, their structure has been altered, resulting in increased fuel loads. Subsequently, managers have been increasingly implementing habitat treatments including prescribed burning, mechanical thinning, and a combination of both treatments to reduce fuel loads and enhance habitat for ungulates. The Rocky Mountain Elk Foundation has partnered with agencies to complete over 10,000 of these treatments across the United States to enhance elk habitat. As treatment impacts to other wildlife species are not well understood, we evaluated the effects of these treatments on the bird and bee communities over varying temporal and spatial factors.
We sampled these communities across eastern Oregon, northern Idaho, and Montana over the summers of 2018 and 2019 at sites treated with prescribed burns, mechanical thins, and thin plus burns, along with paired controls. We evaluated impacts to birds through estimation of the abundance of four focal species and groups of birds, species richness, and species diversity. We found that Mountain Chickadees responded negatively to treatments, and decreased in abundance as surrounding treated area increased, while Bluebirds responded positively to treatments due to removal of the forest canopy. Species richness, diversity, and abundance of Dark-eyed Juncos and Woodpeckers were not impacted by treatments.
Similarly to birds, we estimated abundance, species richness, and species diversity of bees at treated and control sites to assess treatment impacts. Abundance, species richness, and species diversity of bees increased following treatments, largely due to decreased canopy cover at treated sites. Surrounding landscape impacted bee responses, with species diversity increasing with increasing treated area, and abundance increasing with surrounding open area.
Both communities were most impacted by thin-burns than burn treatments, and response to treatment type likely differed because thin-burn treatments removed more canopy and understory vegetation than burn treatments. However, these impacts were time-dependent, with treated sites returning to pre-treatment conditions between 10 and 15 years post-treatment. Overall, we observed positive impacts to the bee community to habitat treatments, while the bird community was largely unaffected by treatments.
Recommended Citation
Oja, Emily Bea, "Bird and Native Bee Responses to Habitat Treatments" (2020). Graduate Student Theses, Dissertations, & Professional Papers. 11599.
https://scholarworks.umt.edu/etd/11599
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© Copyright 2020 Emily Bea Oja