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Gary McCracken


Research Interest

Evolutionary ecology, population genetics


1976 - Ph.D., Cornell University


Population biology, molecular ecology, animal behavior, conservation biology, and the ecology of infectious diseases.

My research concerns the distribution of animals in space, their behavior and interactions, and resulting impacts on genetic population structure. Currently, the organisms are bats, insects, and fungal and viral pathogens. The projects in my lab involve field studies combined with molecular assays, and ongoing collaboration with The Institute for Ecological Modeling at UTK to better inform data collection and to provide predictive analysis and interpretation.

Long-term research interests in my lab involve resource distributions and foraging behaviors of bats and linking the foraging ecology and movements of bats with migration patterns of insects, including major insect crop pests. These efforts employ a variety of field techniques that include acoustic and video studies of the feeding behaviors of bats at ground level and higher altitudes, monitoring the abundances of bats and insects in space and time, and molecular assays of the diets of bats. Collaborative research with the US Department of Agriculture on the aerial dispersal, population dynamics, and availability of major insect pests allows us to assess the ecosystem services provided by insect-eating bats over agricultural and natural landscapes.

Our research interests also concern infectious disease in bats. Our research on the ecological influences on rabies infections in bats strives to better understand the factors that influence the circulation of rabies virus within bat populations. Other research strives to better understand, predict, and ameiliorate the impact of the White Nose Syndrome (WNS) epidemic on North American populations of bats. Research conducted in collaboration with Tom Hallam and others involves empirical and modeling efforts to investigate and predict the geographic spread of the pathogenic fungus Geomyces destructans (Gd) that causes WNS. Other studies focus on behaviors of bats inside and outside of winter roost sites that may affect the differential susceptibility of bats to the disease. This research involves field seasonal surveillance for Gd infections in natural populations of bats that differ in population structure and behavior. Field studies on WNS are conducted in collaboration with federal and regional conservation management agencies and colleagues at several Universities in the US and Canada.


  • Gilbert, A. T., G. F. McCracken, L. L. Sheeler, L. I. Muller, et al. 2015. Rabies surveillance among bats in Tennessee, 1996–2010 J. Wildlife Disease, In Press.
  • Bernard,R.F., J.T. Foster , E.V. Willcox , K.L. Parise and G.F. McCracken. 2015. Novel detections of Pseudogymnoascus destructans on three bat species in the Southeastern United States. J. Wildlife Disease. 51:519-522.
  • Brown, V.A., E. Braun de Torrez, and G.F. McCracken. 2015. Crop pests eaten by bats in organic pecan orchards. Crop Protection 67:66-71.
  • Davidai, N., J.K. Westbrook, J-P. Lessard , T.G. Hallam, and G.F. McCracken. The importance of natural habitats to bats in intensive agricultural landscapes. Biological Conservation, 190: 107-114.
  • Janicki, F., W. F. Frick, A. M. Kilpatrick, K. L. Parise, J. T. Foster, and G. F. McCracken. 2015. Efficacy of Visual Surveys for White-Nose Syndrome at Bat Hibernacula. PloS One 10(7): e0133390.
  • Krauel, J.J., J.K. Westbrook, and G.F. McCracken. 2015. Weather-driven dynamics in a dual-migrant system: moths and bats. Journal of Animal Ecology. 84: 604-614.
  • Wiederholt, R., C. Svancara, L. López-Hoffman, W. Thogmartin, G.F. McCracken, et al. 2015. Optimizing conservation strategies for Mexican free-tailed bats: A population viability and ecosystem services approach. Biodiversity and Conservation 24:63-82.
  • Lopez-Hoffman, L., R. Wiederholt, C. Sansone, K.J. Bagstad, P. Cryan, et al. 2014. Market forces & technological substitutes cause fluctuations in the value of bat pest-control services for cotton. PLoS One 9(2).e87912.
  • Melin, A. D., C.F. Danosi, G.F. McCracken & N.J. Dominy. 2014. Dichromatic vision in a fruit bat with diurnal proclivities: the Samoan flying fox (Pteropus samoensis) J. Comp. Physiol. A. 200:1015-1022.
  • Boyles, G, Sole, C.L., Cryan, P.M. and G.F. McCracken. 2013. On estimating the economic value of insectivorous bats: prospects and priorities for biologists. In. Bat Evolution, Ecology and Conservation. R.A. Adams and S.C. Petersen, Eds. Springer Science Press, NY.
  • Krauel, J.J. and G.F. McCracken. 2013. Recent advances in bat migration research. In. Bat Evolution, Ecology and Conservation. R.A. Adams and S.C. Petersen, Eds. Springer Science Press. NY.
  • Wiederholt, R., L. Lopez-Hoffman, J. Cline, R.A, Medellin, P. et al. 2013. Moving across the border: modeling migratory bat populations. Ecosphere 4(9): 1-16.
  • Hayman, D.T.S., R.A. Bowen, P.M. Cryan, G.F. McCracken, et al. 2012. Ecology of zoonotic infectious diseases in bats: current knowledge and future directions. Zoonoses and Public Health. doi: 10.1111/zph.12000.
  • McCracken, G.F., J.K. Westbrook, V.A. Brown, M. Eldridge, et al. 2012. Bats track and exploit insect pest populations. PLoS ONE. 7(8).e43839.
  • Boyles, J.G., Cryan, PM, McCracken G.F., and Kunz T.H. 2011. Economic importance of bats to agriculture. Science 332: 341-342.
  • Brown, V.A., A. Brooke, J.A. Fordyce, and G.F. McCracken. 2011. Genetic analysis of populations of the threatened bat Pteropus marianus. Conservation Genetics 12:933-941.
  • Gillam, E.H., J.K. Westbrook. P.G. Schleider, and G.F. McCracken. 2011. Virtual bats and real insects: effects of echolocation on pheromone-tracking behavior of male corn earworm moths Helicoverpa zea. SW Naturalist 56: 103-107.
  • Hallam, T.G. and G.F. McCracken. 2011. Culling and the management of the panzootic White Nose Syndrome in hibernating bats. Conservation Biology 25: 189-194.
  • Russell, A.L. Cox, M.P., Brown, V.A., and McCracken, G.F. 2011. Population growth of Mexican free-tailed bats (Tadarida braziliensis Mexicana) predates human agricultural activity. BMC Evolutionary Biology 11:88.

Contact Information

  • 538 Hesler
  • Mailing Address: 569 Dabney Hall, 1416 Circle Dr, Knoxville, TN 37996
  • Phone: (865) 974-6194
  • Fax: (865) 974-3067
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