Current Projects
This page is an introduction to some, but not all, of the projects that I am currently working on. They are listed here with the most complete projects at the bottom of the list. This list shows the broad array of projects that I work on because it shows primarily the projects that I am working on for fun in my spare time. Projects will be removed from this list as they are added to my CV as publications that are in review.
The Columbia torrent salamander, Rhyacotriton kezeri, is endemic to the Pacific Northwest United States, with a small geographic range encompassing NW Oregon and SW Washington. Although this species is both a state and a federal candidate for formal listing, information is completely lacking on its prey. In addition, few studies have addressed diet of any species in this genus, and none have included the diet of larvae. This lack of basic life-history information is a hindrance to the conservation and management of this species, and in particular, limits efforts that seek to better understand the role of torrent salamanders in the headwater ecosystems in which they live.
In collaboration with Casey Richart and Marc Hayes, I am investigating the diet of this species by examining the stomach and intestine contents of a series of preserved specimens that exists in the Burke Museum at the University of Washington. Preliminary results indicate that the diet of this species includes a wide variety of prey, but that copepods are particularly important for larvae and larval flies are particularly important for adults. Our preliminary results were presented at the 2006 meeting of the Society for Northwestern Vertebrate Biology in Olympia, Washington, and the abstract has been published in Northwestern Naturalist.
Although we have learned much about the ecology of Pacifc Northwest forests in recent decades, there are still significant gaps in our knowledge of such basic areas as the structure of food webs and the relative importance of their links. Along with Marc Hayes, Casey Richart (lead author), and several others, I am investigating the diets of Pacific Northwest forest-dwelling amphibians to provide some of the first direct comparisons of prey niches among terrestrial amphibians. Our preliminary results indicate that the importance of molluscs in the diet of amphibians has been historically underestimated, and that there are significant differences among species in their diets in spite of the fact that these are all considered generalist predators. We presented preliminary results from this project at the 2007 meeting of the Society for Northwestern Vertebrate Biology in Victoria, Canada and an abstract of this project was published in Northwestern Naturalist.
As in many species of snake, but unlike the majority of vertebrates, sexually mature females are larger than males. This is the case despite the fact that males compete for access to females. Several explanations have been proposed to explain the "reverse" dimorphism in this species, and in snakes in general. One recent hypothesis that has not been tested is that males are smaller because small males have an advantage in following females around the steep cliffs that surround many of the breeding sites for this species. In collaboration with Bob Mason, I tested several predictions from this hypothesis, including testing male climbing ability as a function of body size in the lab and in the field, and comparing body size of males at dens with different degrees of cliffs surrounding the breeding area. I am in the process of preparing this manuscript for submission to Functional Ecology or Evolution.
Seeps are a unique habitat type where water flows from the ground, as in a spring, but in such low flow that no channel is formed. Seeps may be a critical habitat component for amphibians that live in areas that dry for part of the year. In collaboration with Marc Hayes, Tim Quinn, and Kristen Ryding at the Washington Department of Fish and Wildlife, I tested the hypothesis that some amphibian species use seeps more than other non-seep habitats during the summer. This manuscript is in preparation for submission to Wetlands.
Updated 17 February 2009