July 1997 - June 1999
Joseph Kiesecker, Ph.D.

Joseph Kiesecker was selected as the first Gaylord Donnelley Environmental Fellow in the spring of 1997. He received his Ph.D. degree in zoology from Oregon State University in May of 1997 and shortly after arrived at the Yale School of Forestry and Environmental Studies (F&ES) to begin a two-year collaboration with David Skelly, assistant professor of ecology forestry at F&ES. While at Yale, his goal was to investigate the influence of fungal pathogens on the distribution of larval amphibians, and dynamics of their communities. The following is his report on his accomplishments while he was at Yale:

Research

During my time at Yale, I have collaborated with several scientists, including graduate students, post-doctoral fellows and professors. I have had the opportunity to pursue my interest in disease ecology. This has led me to examine the effects of pathogenic infection on behavioral interactions. I investigated how infection with pathogens may influence social interactions between larval amphibians. In laboratory experiments, tadpoles avoid associating with conspecifics infected with intestinal pathogens. This is an exciting result. This is one of the first demonstrations that animals can recognize and use behavior to avoid pathogenic infection. These results will have important ramifications for the understanding of disease transmission. This work has been accepted for publication in the Proceedings of the National Academy of Sciences, USA (see below).

I have also had the opportunity to examine the role that disease plays in regulating host populations. Diseases and pathogens are receiving increasing recognition as sources of mortality in animal populations. However, from an ecological standpoint, pathogens have been largely neglected. The work I have conducted with digenetic trematode infections in larval amphibians has shown how environmental change can influence disease outbreaks and ultimately host populations. This work is also exciting. It is not only one of the few demonstrations that a pathogen can influence host population regulation, but also shows how environmental change can alter host-pathogen interactions. These results will improve our understanding of disease ecology and the role of disease in conservation issues. This work has resulted in the submission of two manuscripts that are currently in review (see below).

In addition, I have continued to collaborate with researchers at Oregon State University and the University of Maine. This collaborative work has allowed me to continue to pursue my interest in amphibian conservation and behavioral ecology. Work form these research projects has resulted in 8 manuscripts (see below). While at Yale I have also begun a collaboration with Dr. David Skelly (Yale School of Forestry and Environmental Studies and the Department of Ecology and Evolutionary Biology), that will maintain my link with Yale University even after I move to Pennsylvania State University's Biology Department as an assistant professor. I have worked with Dr. Skelly on his projects that examine the role of food resources and the ecology of larval amphibian communities and how large scale changes in forest canopy cover can alter these associations. This work has resulted in two publications that are currently in review (see below).

While in residence at Yale I have submitted 16 manuscripts, 11 of which have been accepted for publication (see below). I have enclosed copies of those manuscripts where reprints or preprints were available. In addition, I have enclosed copies of news articles that reported on research that was conducted during my time as Donnelley Fellow.

Manuscripts resulting from Donnelley Fellowship support:

Kiesecker, J.M. and A.R. Blaustein.1998. Effects of introduced bullfrogs and small mouth bass on the microhabitat use, growth and survival of native red-legged frogs. Conservation Biology. 12:776-787.

Kiesecker, J.M. 1998. (Book Review): Amphibians in decline: Canadian studies of a global problem. Edited by David M. Green. Copeia 1998:813-815.

Blaustein, A.R., Kiesecker, J.M., Chivers, D.P. and R.G. Anthony. 1997. Ambient UV-B radiation causes deformities in amphibian embryos. Proceedings of the National Academy of Science, USA. 94:13735-13737.

Marco, A., Kiesecker, J.M., Chivers, D.P. and Blaustein, A.R. 1998. Sex recognition and mate choice by male western toads (Bufo boreas). Animal Behaviour, 55:1631-1635.

Wildy, E.L., Chivers, D.P., Kiesecker, J.M. and A.R. Blaustein. 1998. The effects of intraspecific predation on growth in larval long-toed salamanders, Ambystoma macrodactylum. Journal of Herpetology. 32:286-289.

Blaustein, A.R. Kiesecker, J.M. et al. 1999. Using field experiments to examine the effects of ultraviolet radiation on amphibians. American Zoologist. 38:799-812.

Kiesecker, J.M., Chivers, D.P., Marco, A., Quilchano, C., Anderson, M.T and A.R. Blaustein. 1999. Identification of a disturbance signal in larval red-legged frogs (Rana aurora). Animal Behaviour. 57:1295-1300.

Kiesecker, J.M., Skelly, D.K., Beard, K. and E. Pressier. Behavioral Reduction of Infection Risk. In Press Proceedings of the National Academy of Sciences, USA.

Kiesecker, J.M. and A.R. Blaustein. Pathogen reverses competition between larval amphibians. In Press Ecology.

Blaustein, A.R. Hoffman, P., Hayes, J.B., Chivers, D.P., Kiesecker, J.M., et al. The influence of ambient UV-B on embryos of the spotted frog (Rana pretiosa). In Press Ecological Applications.

Blaustein, A.R., Chivers, D.P., Kats, L.B. and J.M. Kiesecker. Effects of Ultraviolet Radiation on Locomotion and Orientation in Roughskin Newts (Taricha granulosa) . In Press Ethology.

Kiesecker, J.M. and D.K. Skelly. Interactions of disease and pond drying on the growth, development and survival of the gray treefrog (Hyla versicolor). Submitted to Ecology. 38 pages.

Kiesecker, J.M. and D.K. Skelly. Choice of oviposition site by gray treefrogs, Hyla versicolor: the role of potential parasitic infection. Submitted to Ecology. 21 pages.

Kiesecker, J.M., Miller, C.L. and A.R. Blaustein. Potential mechanisms underlying the displacement of native red-legged frogs by introduced bullfrogs. Submitted to Ecology. 37 pages.

Skelly, D.K. and J.M. Kiesecker. The importance of larval competition in amphibian assemblages: comparison of experimental venue using a metaanalysis. Submitted to American Naturalist. 31 pages.

Skelly, D.K., Freidenberg, L.K. and J.M. Kiesecker. Forest canopy and the performance of larval amphibians. Submitted to Ecology. 33 pages.

Additional Work:

I have had the opportunity to guest lecture in the Conservation Biology and Landscape Ecology courses offered by the School of Forestry and Environmental Studies. In addition, I was an instructor at the Yale Society for Conservation Biology Weekend Methods Retreat at the Great Mountain Field Station in September 1997. I have also taken advantage of the numerous talks and seminars that are presented by the School of Forestry and Environmental Studies and the Ecology and Evolutionary Biology Department. I have also been invited to present the results of my research at other universities (see below).

Invited Seminars while at Yale:

• University of Connecticut, Department of Ecology and Evolutionary Biology, November 1997
• University of Maine, Department of Biological Sciences, December 1997
• Hartwick College, Department of Biology, May 1998
• Pennsylvania State University, Department of Biology, December 1998

In addition to these activities, I have continued to share the results of my research with members of the scientific community. I was invited to speak in a symposium (Development in a Volatile World: How Embryos Cope With Environmental Stress) at the American Association for the Advancement of Science 150th Anniversary Meeting, Philadelphia, Pennsylvania, February1998.

I have also presented the results of research at several professional meetings including: the Society for Conservation Biology's annual meeting in Sydney, Australia, July 1998; American Society of Ichthyologists and Herpetologist's annual meeting in University Park, Pennsylvania, June 1999; The annual meeting of the Association for the Study of Animal Behaviour in Harrisburg, Pennsylvania, July 1999.