Header image  
University of South Florida  
line decor
line decor
Thomas Raffel, Ph.D.
 Post-Doctoral Researcher

Tom running a temperature experiment

Research Projects

Temperature variability and chytridiomycosis


Agrochemical effects on trematode parasites


Parasite community ecology


Seasonal parasitism in red-spotted newts


Leech transmission of amphibian Ichthyophonus


Contact Information

Office: SCA 322
Phone: 813/974-4694
Email: traffel[at]cas.usf.edu

Mailing Address
Department of Integrative Biology
University of South Florida
4202 E. Fowler Ave., SCA 110
Tampa, FL 33620

Ph.D. Biology, Penn State University, 2006
B.A. Zoology, Ohio Wesleyan University, 2001


Parasitism and disease are increasingly recognized as important factors in animal ecology, capable of influencing population dynamics, reproductive strategies, and patterns of host diversity.  But important general questions remain largely unanswered, such as what are the primary drivers of spatiotemporal patterns of parasitism, and are parasite effects on hosts comparable to effects of predators or competitors?  To answer these questions, I believe parasite ecologists must work across multiple scales and disciplines, considering potential interactions with factors such as predation, environmental temperature, and host immunity.  My approach to determining the important drivers of parasite dynamics is to first derive hypotheses from field patterns and then to test them using manipulative experiments in the field or in mesocosms.


Recent Publications

Raffel, T. R., J. O. Lloyd-Smith, S. K. Sessions, P. J. Hudson, and J. R. Rohr.  (in press).  Does the early frog catch the worm?  Disentangling potential drivers of a parasite age-intensity relationship in tadpoles.  Oecologia.

Jennings, D. E., J. J. Krupa, T. R. Raffel and J. R. Rohr.  (in press).  Evidence for competition between carnivorous plants and spiders.  Proceedings of the Royal Society of London Series B-Biological Sciences.

Rohr, J. R., T. R. Raffel, and C. A. Hall*.  (in press).  Developmental variation in resistance and tolerance in a multi-host-parasite system.  Functional Ecology.

Raffel, T. R., J. T. Hoverman, N. T. Halstead, P. J. Michel*, and J. R. Rohr.  2010.  Parasitism in a community context: Trait-mediated interactions with competition and predation.  Ecology.  91:1900-1907.

Rohr, J. R. and T. R. Raffel.  2010.  Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease.  Proceedings of the National Academy of Science of the United States of America.  107: 8269–8274.

Raffel, T. R., J. L. Sheingold*, and J. R. Rohr.  2009.  Lack of pesticide toxicity to Echinostoma trivolvis eggs and miracidia.  Journal of Parasitology.  95: 1548–1551.

Raffel, T. R. and T. K. Anderson.  2009.  A new species of Hysterothylacium (Nematoda: Anisakidae) from the stomach of the red-spotted newt, Notophthalmus viridescens, from Pennsylvania fishless ponds.  Journal of Parasitology.  95: 1503–1506.

Rohr, J.R., Swan, A., Raffel, T.R., Hudson, P.J. 2009. Parasites, info-disruption, and the ecology of fear. Oecologia. 159: 447-454

Raffel, T.R., Le Gros, R.J., Love, B.C., Rohr, J.R., Hudson, P.J. 2009. Parasite age-intensity relationships in red-spotted newts: does immune memory influence salamander disease dynamics? International Journal for Parasitology. 39: 231-241

Raffel, T.R., Bommarito, T., Barry, D.S., Witiak, S.M., Shackleton, L.A. 2008. Widespread infection of the Eastern red-spotted newt (Notophthalmus viridescens) by a new species of Amphibiocystidium, a genus of fungus-like mesomycetozoan parasites not previously reported in North America. Parasitology. 135: 203-215

Rohr, J.R., Raffel, T.R., Romansic, J., McCallum, H., Hudson, P.J. 2008. Evaluating the links between climate, disease spread, and amphibian declines. PNAS. 45: 17436-17441

Rohr, J.R., Schoetthofer, A.M., Raffel, T.R., Carrick, H.J., Halstead, N., Hoverman, J.T., Johnson, C.M., Johnson, L.B., Lieske, C., Piwoni, M.D., Schoff, P.K., Beasley, V.R. 2008. Agrochemicals increase trematode infections in a declining amphibian species. Nature. 455: 1235-1239

Raffel, T.R., Martin, L.B., Rohr, J.R. 2008. Parasites as predators: unifying natural enemy ecology. Trends in Ecology and Evolution. 23: 610-618 (invited submission)

Rohr, J.R., Raffel, T.R., Sessions, S.K., Hudson, P.J. 2008. Understanding the net effects of pesticides on amphibian trematode infections. Ecological Applications. 18: 1743-1753

Raffel, T.R., Dillard, J.R., Hudson, P.J. 2006. Field evidence for leech-borne transmission of amphibian Ichthyophonus sp. Journal of Parasitolology 92: 1256-1264

Raffel, T.R., Rohr, J.R., Kiesecker, J.M., Hudson, P.J. 2006. Negative effects of changing temperature on amphibian immunity under field conditions. Functional Ecology 20: 819-828

Raffel, T.R., Gatz, A.J. 2003. The orientation of beavers (Castor canadensis) when cutting trees. The Ohio Journal of Science 103: 143-146

Raffel, T.R., Register, K.B., Marks, S.A., Temple, L.M. 2002.  Prevalence of Bordetella avium in wild and domestic bird species of eastern USA. Wildlife Diseases  38: 40-4


In the News

July 2010 - Parasite of the Day: Hysterothylacium burtii

August 2009 - Scientific American: "Is the frog-killing chytrid fungus fueled by climate fluctuations?"

May 2007 - The Scientist: "A new dynamic"

February 2007 - The Philadelphia Inquirer: "The knotty problem of what infects the newt"


Orginal Raffel Songs

Science and conservation songs:
        My monkey mind

        Children of the rain

Academic Blues” songs:
        Academic blues
        My-data-mean-nothing blues
        Publication blues
        Students in my hall