Publication Date


Date of Final Oral Examination (Defense)


Type of Culminating Activity


Degree Title

Master of Science in Biology



Major Advisor

James C. Munger, Ph.D.


Ian C. Robertson, Ph.D.


Peter Koetsier, Ph.D.


This thesis examines topics relevant to Columbia spotted frogs (Rana luteiventris) in the Owyhee Uplands of southwestern Idaho. First, I present a detailed discussion of both the ecology and conservation status of spotted frogs. Concerns about declining spotted frog numbers in the southern portions of the species’ range were first expressed in the early 1990’s. In response, several studies on the behavior and ecology of spotted frog have been conducted by Boise State University. In addition, the Idaho Department of Fish and Game monitors the status of spotted frogs in the Owyhees using an occupancy model developed and implemented in 2007. For the most part, the population comprises small, semi-isolated breeding groups and is genetically structured by the drainages that it occupies. Spotted frogs in the Owyhees are listed as a species of concern under the Endangered Species Act of 1973.

Stoneman Creek in the Owyhees housed a robust population of spotted frogs that relied on habitat provided by a beaver dam, until the beaver were lost from the site in 1992. Following the loss of beaver at Stoneman Creek, the dam began to erode, eventually resulting in the loss of suitable habitat for spotted frogs. By 1998, surveys for spotted frogs along Stoneman Creek indicated a potential loss of the population. In an attempt to restore declining spotted frog habitat along Stoneman Creek, 5 beavers were released at the eroding beaver dam in 2001. At least one beaver settled along the stream and enhanced the eroding beaver dam, thus improving spotted frog habitat. The spotted frog population rapidly rebounded following beaver reintroduction to the stream. I found that spotted frog recruitment within the improved habitat occurred in two ways: through immigration and successful breeding.

I constructed a field experiment designed to look at the permeability of uplands to movements by newly metamorphosed spotted frogs. Because overland movements by frogs pose a high risk of desiccation, it is unclear whether frogs can undergo terrestrial movements to access wetlands for foraging and suitable overwintering habitat for individual survival and whether among-population movements can take place. I found that spotted frog metamorphs do in fact undertake small-scale terrestrial movements. Terrestrial movements occurred mostly overnight. With increasingly dry conditions, the probability of movements occurring became increasingly dependent on dropping temperatures. Dropping temperatures were used in analyses as a correlate for precipitation.

Included in

Zoology Commons