Undergraduate Abstract

Deanna Morrell
May 2006

Population Trends of Wintering Bald Eagles (Haliaeetus Leucocephalus) at the Lake Mead National Recreation Area, Nevada

A Thesis submitted in partial satisfaction
of the requirement for the degree of

Bachelor of Science

In

Department of Environmental Studies
University of Nevada Las Vegas

By

Deanna Morrell

May 2006

Content Advisors:
Ross Haley, Wildlife Program Manager
Ross_Haley@nps.gov

Chad L. Cross, Ph.D., School of Public Health, UNLV
Chad.Cross@unlv.edu

Class Advisor:
Timothy J. Farnham, Ph.D., Assistant Professor, Department of Environmental Studies, UNLV
Timothy.Farnham@UNLV.edu

ENV 499 A & B

ABSTRACT

The purpose of this study was to look at population trends of wintering bald eagles (Haliaeetus Leucocephalus) at the Lake Mead National Recreation Area, Nevada from 1991 to 2006. Bald eagles were counted on January 5, 2006 along the entire shoreline of Lake Mead and Lake Mohave. This study focused on two questions: (1) how has the population changed over time? (2) How has the proportion of juvenile eagles to adult eagles changed over time? Question one was supported with the number of bald eagles significantly increasing (r=0.76, p=0.002). Question two was supported as the proportion of juveniles to adults was not significant (F112 =0.54, p=0.48). Lake Mead NRA saw a total of 67 bald eagles (31 adults, 36 juveniles) with the Overton Arm having the highest number of bald eagle sightings. Prior to 2000 data collection was not standardized from the Lake Mead NRA, therefore resulting data should be interpreted with caution. The bald eagle is currently a threatened species under the Endangered Species Act and future studies are important to determine the suitability of delisting.