In recent decades, many amphibian populations have declined worldwide. Human-induced habitat disturbance and alteration have been cited as a dominate causes, which can interact with other stressors such as climate change and disease. In the majority of cases, however, mechanisms underlying declines are considered enigmatic; therefore, developing a better understanding of the individual and interactive factors threating amphibians will be critical to prevent further population declines and species extinctions.

Spatially isolated populations of species, especially those with limited mobility, are at an increased risk of extirpation. Though Columbia spotted frogs (Rana luteiventris) have a widespread range throughout western North America…

A species that forages on snowfields and tundra during the breeding season, the Black Rosy-Finch is an alpine breeding obligate that uses cracks in cliff faces for nesting sites.

The Island-Scrub Jay, Aphelocoma insularis, has been the focus of demographic research since 2008. Our work is motivated by threats to the species viability posed by its limited range and population size, and seeks to understand the factors that determine the distribution and abundance of A. insularis on Santa Cruz Island.

This project investigates the effects of habitat alteration from energy development on songbird nest success. We aim to identify the relationship between nest predation rates and small mammal abundance, and examine possible mechanisms driving the increased abundance of rodent nest predators.

Completed Projects

Rapid climate change is one of the defining conservation issues of the 21st century. The effects of changing conditions are seen in most of the biomes on earth and influence all levels of ecological hierarchy – from individual species behavior to entire ecosystem processes.

Lodgepole pine (Pinus contorta) forests of the Intermountain West are currently experiencing a widespread epidemic of the mountain pine beetle (Dendroctonus ponderosae), due in part to climate change.

Invasive species are one of the most significant threats to native flora and fauna worldwide. Habitat alteration by invasive plants can have direct and indirect effects on fitness with consequences for populations and communities of native wildlife. Small mammals are an integral component of many ecosystems, however, the effects of invasive plants on small mammals are poorly understood. This study addresses a critical information need by determining how small mammal populations and communities respond to habitat alteration by cheatgrass (Bromus tectorum), a widespread invasive plant in North America.

Distinctive life-history traits of the pika such as their sensitivity to temperature, limited dispersal ability and occurrence in small isolated populations render them particularly vulnerable to climate change.

The Powder River Basin of Wyoming has undergone extensive energy development in recent decades. We analyzed a 9-yr dataset of over 3,000 nests of 18 raptor species to determine the trends in nest site use between 2003-2011 and to test for any influence of energy development on nest site use.

The umbrella species concept holds promise as a shortcut to broad-reaching wildlife management and conservation. In this project, we assessed whether dozens of at-risk wildlife species benefit under the umbrella of sage-grouse conservation efforts in Wyoming, and why.

Anthropogenic disturbances can lead to wildlife population declines due to habitat loss and changes in habitat quality. Understanding wildlife responses to these changes can aid us in mediating impacts to wildlife.