First Advisor

Kris Voss


Regis College

Degree Name

MS Environmental Biology

Document Type

Thesis - Open Access

Number of Pages

68 pages


The extraction and changes to management of natural resources can have profound negative effects on local fauna, potentially causing local extirpation of many species. Fauna requiring specific habitats to thrive can be especially susceptible to disruption, such as Bald Eagles (Haliaeetus leucocephalus), requiring advanced consideration in management practices. In this study, I studied Bald eagle preferences in roosting sites between trees and ice, and how life stage may affect roosting height within three vertical sections of the canopy at Barr Lake State Park, in Brighton, CO. I conducted stationary counts of Bald Eagles roosting on ice and in the adjacent riparian area, specifically parsing out counts between ages and height in trees. Bald Eagles were found to significantly prefer trees over ice for roosting areas, despite more physical area on the ice being available for resting. Once in the trees, adult Bald Eagles preferred the upper two-thirds of the canopy, whereas juveniles preferred the lower two-thirds. The preference of trees over ice for roosting areas implies the critical nature of suitable habitat, with implications from age stratification within the canopy needing to be taken into account. The outcomes of this study highlight a conflict in management projects within Barr Lake, though recommendations can be generalized to any riparian management plan.

Date of Award

Spring 2024

Location (Creation)

Denver, Colo.

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