Behavior and Ethology Commons^™

Selection Of Forage And Avoidance Of Predation Risk By Partially Migratory Mule Deer, Collin Jeffrey Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Migration by ungulates has traditionally been thought of as a strategy that increases access to forage quality or reduces exposure to risk of predation, but the benefits of migration may be waning globally. In partially migratory populations, the persistence of both migrant and resident strategies is an intriguing ecological phenomenon, because migrants and residents often face contrasting fitness consequences. Partial migration is common in mule deer (Odocoileus hemionus), a species that has experienced widespread declines across the western United States during recent decades. Mule deer seldom switch between migratory strategies throughout their lifetime, which may make them less resilient to …

Resource Selection And Calving Success Of Moose In Colorado, Forest P. Hayes

Graduate Student Theses, Dissertations, & Professional Papers

Across much of North America, moose populations (Alces alces) are declining due to disease, predation, climate, and anthropogenic pressures. Despite this, populations of moose in Colorado have continued to grow. Studying successful (i.e., persistent or growing) populations of moose can facilitate the continued conservation of the species by identifying habitat features critical for moose persistence.

First, I evaluated calving success of moose in Colorado and the impact of willow habitat quality and nutrition. I then estimated the probability of female moose having a calf using repeated observations in a Bayesian occupancy model. I assigned values for dry matter …

Heat For The Masses: Thermal Ecology Of The Western Tent Caterpillar, Victoria Dahlhoff

Graduate Student Theses, Dissertations, & Professional Papers

A unique feature of some gregarious, colonial insects is their ability to create external structures that alter environmental conditions for the entire (often family) group. A combination of physical alteration of local microhabitats and behavioral thermoregulation allows many of these animals to actively control their body temperatures, which allows them to regulate energy use and metabolism in variable thermal environments. Here I describe mechanisms of microhabitat modification and thermal regulation in the western tent caterpillar, Malacosoma californicum pluviale. Tent caterpillars build communal silk tents, whose temperatures can rise substantially above ambient air temperature. I experimentally manipulated colony sizes and examined …