Tom O'Shea is a Scientist Emeritus at the USGS Fort Collins Science Center.
Tom O'Shea has conducted research on bats, sirenians, and other mammals in the U.S., Africa, South and Central America, Asia, and Oceania. Dr. O'Shea is the author or co-author of about 140 scientific publications. He was formerly a researcher with the USGS, National Biological Service, and U.S. Fish and Wildlife Service. His current research emphasis is on bats (after a long hiatus in marine mammal studies and federal research management), particularly topics related to diseases, population biology, natural history, and environmental contaminants.
Professional Experience
Scientist Emeritus, U.S. Geological Survey, Fort Collins Science Center 2009-present
Research Wildlife Biologist, U.S. Geological Survey, Fort Collins Science Center 2001-2009
Branch Chief, U.S. Geological Survey, Fort Collins Science Center 1996-2001
Assistant Director, U.S. Fish and Wildlife Service/National Biological Survey, National Ecology Research Center/Midcontinent Ecological Science Center, Fort Collins 1992-1996
Research Wildlife Biologist, Sirenia Project Leader, Field Station Leader, U.S. Fish and Wildlife Service, National Fish and Wildlife Laboratory/National Ecology Research Center, Gainesville, Florida 1979-1992
Research Zoologist, Patuxent Wildlife Research Center, Laurel, Maryland 1977-1979
Education and Certifications
Ph.D. Zoology, Northern Arizona University, 1977
M.S. Biological Sciences, Northern Arizona University, 1973
B.S. Zoology, Colorado State University 1970
Affiliations and Memberships*
American Society of Mammalogists
National Museums of Kenya
Florida Museum of Natural History
Museum of Southwestern Biology (University of New Mexico)
California Academy of Sciences
Colorado State University
University of Florida
University of North Carolina at Wilmington
Wildlife-At-Risk (Vietnam)
Advisory committees of a number of national and international conservation organizations and agencies, including the Committee of Scientific Advisors to the US Marine Mammal Commission.
Science and Products
Filter Total Items: 111
United States bat species of concern: A synthesis
In 1994 the federal government designated 24 species or subspecies of bats in the United States (U.S.) and its territories as Category 2 candidates for listing as Endangered or Threatened under the U.S. Endangered Species Act. Category 2 was eliminated in 1996, but taxa previously receiving this designation were informally considered “species of concern”. Various state and federal agencies and co
Genetic mark–recapture improves estimates of maternity colony size for Indiana bats
Genetic mark–recapture methods are increasingly being used to estimate demographic parameters in species where traditional techniques are problematic or imprecise. The federally endangered Indiana bat Myotis sodalis has declined dramatically and threats such as white-nose syndrome continue to afflict this species. To date, important demographic information for Indiana bats has been difficult to es
Multiple mortality events in bats: a global review
Despite conservation concerns for many species of bats, factors causing mortality in bats have not been reviewed since 1970. Here, we review and qualitatively describe trends in the occurrence and apparent causes of multiple mortality events (MMEs) in bats around the world.
We compiled a database of MMEs, defined as cases in which ≥ 10 dead bats were counted or estimated at a specific location wi
Seasonal shifts in the diet of the big brown bat (Eptesicus fuscus), Fort Collins, Colorado
Recent analyses suggest that the big brown bat (Eptesicus fuscus) may be less of a beetle specialist (Coleoptera) in the western United States than previously thought, and that its diet might also vary with temperature. We tested the hypothesis that big brown bats might opportunistically prey on moths by analyzing insect fragments in guano pellets from 30 individual bats (27 females and 3 males) c
Bat flight and zoonotic viruses
Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the su
Variability in seroprevalence of rabies virus neutralizing antibodies and associated factors in a Colorado population of big brown bats (Eptesicus fuscus)
In 2001–2005 we sampled permanently marked big brown bats (Eptesicus fuscus) at summer roosts in buildings at Fort Collins, Colorado, for rabies virus neutralizing antibodies (RVNA). Seroprevalence was higher in adult females (17.9%, n = 2,332) than males (9.4%, n = 128; P = 0.007) or volant juveniles (10.2%, n = 738; P
Genetic characterization of the Pacific sheath-tailed bat (Emballonura semicaudata rotensis) using mitochondrial DNA sequence data
Emballonura semicaudata occurs in the southwestern Pacific and populations on many islands have declined or disappeared. One subspecies (E. semicaudata rotensis) occurs in the Northern Mariana Islands, where it has been extirpated from all but 1 island (Aguiguan). We assessed genetic similarity between the last population of E. s. rotensis and 2 other subspecies, and examined genetic diversity on
Prevalence of neutralizing antibodies to rabies virus in serum of seven species of insectivorous bats from Colorado and New Mexico, United States
We determined the presence of rabies-virus-neutralizing antibodies (RVNA) in serum of 721 insectivorous bats of seven species captured, sampled, and released in Colorado and New Mexico, United States in 2003-2005. A subsample of 160 bats was tested for rabies-virus RNA in saliva. We sampled little brown bats (Myotis lucifugus) at two maternity roosts in Larimer County, Colorado; big brown bats (Ep
A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?
Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors
Ecology of zoonotic infectious diseases in bats: current knowledge and future directions
Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spillover
Bats of Mesa Verde National Park, Colorado: Composition, reproduction, and roosting habits
We determined the bat fauna at Mesa Verde National Park (Mesa Verde) in 2006 and 2007, characterized bat elevational distribution and reproduction, and investigated roosting habits of selected species. We captured 1996 bats of 15 species in mist nets set over water during 120 nights of sampling and recorded echolocation calls of an additional species. The bat fauna at Mesa Verde included every spe
Non-USGS Publications**
Helm, R.C., D.P. Costa, T.D. DeBruyn, T.J. O'Shea, R.S. Wells, and T.M. Williams. 2015. Overview of effects of oil on marine mammals. P. 455-484, in M. Fingas (ed.) Handbook of Oil Spill Science and Technology. John Wiley & Sons, Inc., Hoboken, NJ
Luis, A.D., T.J. O'Shea, D.T.S. Hayman, J.L.N. Wood, A.A. Cunningham, A. T. Gilbert, J.N. Mills, and C.T. Webb. 2015. Network analysis of host-virus communities in bats and rodents reveals determinants of cross-species transmission. Ecology Letters 18:1153-1162. DOI: 10.1111/ele.12491
Marsh, H., T. O’Shea, and J. Reynolds. 2011. Ecology and conservation of the Sirenia: dugongs and manatees. Cambridge University Press, Cambridge, UK. 538 p.
O’Shea, T.J. 2014. Family Trichechidae. P. 548-562 in D.E. Wilson and R.A. Mittermeier, eds. Handbook of Mammals of the World 4. Sea Mammals. Lynx Editions, Barcelona.
Peel, A.J., J. R. C. Pulliam, A. D. Luis, R. K. Plowright, T. J. O’Shea, D. T. S. Hayman, J. L. N. Wood, C. T. Webb, and O. Restif. 2014. The effect of seasonal birth pulses on pathogen persistence in wild mammal populations. Proceedings of the Royal Society B-Biological Sciences B 281: 20132962 (pages 1-9).
Restif, O., Hayman, D.T.S., J.R.C. Pulliam, R.K. Plowright, D.B. George, A.D. Luis, A.A. Cunningham, R.A. Bowen, A.R. Fooks, T.J. O'Shea, J.L.N. Wood, and C.T. Webb. 2012. Model-guided fieldwork: practical guidelines for multidisciplinary research on wildlife ecological and epidemiological dynamics. Ecology Letters 15:1083-1094. DOI: 10.1111/j.1461-0248.2012.01836.x
Son, N.T., T.J. O’Shea, J.A. Gore, G. Csorba, V.T. Tu, T. Oshida, H. Endo, and M. Motokawa. 2016. Bats (Mammalia: Chiroptera) of the southeastern Truong Son Mountains, Quang Ngai Province, Vietnam. Journal of Threatened Taxa 8:8953-8969. DOI: httpdx.dofi.org/10.11609/jot.2785.8.7.8953-8969
Webber, Q.M.R., Brigham, R.M., Park, A.D., Gillam, E.H., O'Shea, T.J., and Willis, C.K.R. 2016, Social network characteristics and predicted pathogen transmission in summer colonies of female big brown bats (Eptesicus fuscus). Behavioral Ecology and Sociobiology 70: 701-712. DOI: 10.1007/s00265-016-2093-3
Woolf, A. and T. J. O'Shea. 1968. Two bighorn sheep-coyote encounters. Journal of Mammalogy 49: 770. DOI: 10.2307/1378747
Woolf, A., T. J. O'Shea and D. L. Gilbert. 1970. Movements and behavior of bighorn sheep on summer ranges in Yellowstone National Park. Journal of Wildlife Management 34: 446-450. DOI: 10.2307/3799031
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Indiana Bat fecal DNA study, Indianapolis, IN Summer 2008
The endangered Indiana bat (Myotis sodalis) has declined dramatically and continuing threats have made it necessary to understand population dynamics and life history throughout the year. Specifically, demographic information (e.g., population size, reproductive success, survival) from the summer range where females raise their young in maternity colonies is difficult to estimate precisely using t
Science and Products
- Publications
Filter Total Items: 111
United States bat species of concern: A synthesis
In 1994 the federal government designated 24 species or subspecies of bats in the United States (U.S.) and its territories as Category 2 candidates for listing as Endangered or Threatened under the U.S. Endangered Species Act. Category 2 was eliminated in 1996, but taxa previously receiving this designation were informally considered “species of concern”. Various state and federal agencies and coGenetic mark–recapture improves estimates of maternity colony size for Indiana bats
Genetic mark–recapture methods are increasingly being used to estimate demographic parameters in species where traditional techniques are problematic or imprecise. The federally endangered Indiana bat Myotis sodalis has declined dramatically and threats such as white-nose syndrome continue to afflict this species. To date, important demographic information for Indiana bats has been difficult to esMultiple mortality events in bats: a global review
Despite conservation concerns for many species of bats, factors causing mortality in bats have not been reviewed since 1970. Here, we review and qualitatively describe trends in the occurrence and apparent causes of multiple mortality events (MMEs) in bats around the world. We compiled a database of MMEs, defined as cases in which ≥ 10 dead bats were counted or estimated at a specific location wiSeasonal shifts in the diet of the big brown bat (Eptesicus fuscus), Fort Collins, Colorado
Recent analyses suggest that the big brown bat (Eptesicus fuscus) may be less of a beetle specialist (Coleoptera) in the western United States than previously thought, and that its diet might also vary with temperature. We tested the hypothesis that big brown bats might opportunistically prey on moths by analyzing insect fragments in guano pellets from 30 individual bats (27 females and 3 males) cBat flight and zoonotic viruses
Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the suVariability in seroprevalence of rabies virus neutralizing antibodies and associated factors in a Colorado population of big brown bats (Eptesicus fuscus)
In 2001–2005 we sampled permanently marked big brown bats (Eptesicus fuscus) at summer roosts in buildings at Fort Collins, Colorado, for rabies virus neutralizing antibodies (RVNA). Seroprevalence was higher in adult females (17.9%, n = 2,332) than males (9.4%, n = 128; P = 0.007) or volant juveniles (10.2%, n = 738; PGenetic characterization of the Pacific sheath-tailed bat (Emballonura semicaudata rotensis) using mitochondrial DNA sequence data
Emballonura semicaudata occurs in the southwestern Pacific and populations on many islands have declined or disappeared. One subspecies (E. semicaudata rotensis) occurs in the Northern Mariana Islands, where it has been extirpated from all but 1 island (Aguiguan). We assessed genetic similarity between the last population of E. s. rotensis and 2 other subspecies, and examined genetic diversity onPrevalence of neutralizing antibodies to rabies virus in serum of seven species of insectivorous bats from Colorado and New Mexico, United States
We determined the presence of rabies-virus-neutralizing antibodies (RVNA) in serum of 721 insectivorous bats of seven species captured, sampled, and released in Colorado and New Mexico, United States in 2003-2005. A subsample of 160 bats was tested for rabies-virus RNA in saliva. We sampled little brown bats (Myotis lucifugus) at two maternity roosts in Larimer County, Colorado; big brown bats (EpA comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?
Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factorsEcology of zoonotic infectious diseases in bats: current knowledge and future directions
Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spilloverBats of Mesa Verde National Park, Colorado: Composition, reproduction, and roosting habits
We determined the bat fauna at Mesa Verde National Park (Mesa Verde) in 2006 and 2007, characterized bat elevational distribution and reproduction, and investigated roosting habits of selected species. We captured 1996 bats of 15 species in mist nets set over water during 120 nights of sampling and recorded echolocation calls of an additional species. The bat fauna at Mesa Verde included every speNon-USGS Publications**
Helm, R.C., D.P. Costa, T.D. DeBruyn, T.J. O'Shea, R.S. Wells, and T.M. Williams. 2015. Overview of effects of oil on marine mammals. P. 455-484, in M. Fingas (ed.) Handbook of Oil Spill Science and Technology. John Wiley & Sons, Inc., Hoboken, NJ
Luis, A.D., T.J. O'Shea, D.T.S. Hayman, J.L.N. Wood, A.A. Cunningham, A. T. Gilbert, J.N. Mills, and C.T. Webb. 2015. Network analysis of host-virus communities in bats and rodents reveals determinants of cross-species transmission. Ecology Letters 18:1153-1162. DOI: 10.1111/ele.12491Marsh, H., T. O’Shea, and J. Reynolds. 2011. Ecology and conservation of the Sirenia: dugongs and manatees. Cambridge University Press, Cambridge, UK. 538 p.O’Shea, T.J. 2014. Family Trichechidae. P. 548-562 in D.E. Wilson and R.A. Mittermeier, eds. Handbook of Mammals of the World 4. Sea Mammals. Lynx Editions, Barcelona.Peel, A.J., J. R. C. Pulliam, A. D. Luis, R. K. Plowright, T. J. O’Shea, D. T. S. Hayman, J. L. N. Wood, C. T. Webb, and O. Restif. 2014. The effect of seasonal birth pulses on pathogen persistence in wild mammal populations. Proceedings of the Royal Society B-Biological Sciences B 281: 20132962 (pages 1-9).Restif, O., Hayman, D.T.S., J.R.C. Pulliam, R.K. Plowright, D.B. George, A.D. Luis, A.A. Cunningham, R.A. Bowen, A.R. Fooks, T.J. O'Shea, J.L.N. Wood, and C.T. Webb. 2012. Model-guided fieldwork: practical guidelines for multidisciplinary research on wildlife ecological and epidemiological dynamics. Ecology Letters 15:1083-1094. DOI: 10.1111/j.1461-0248.2012.01836.xSon, N.T., T.J. O’Shea, J.A. Gore, G. Csorba, V.T. Tu, T. Oshida, H. Endo, and M. Motokawa. 2016. Bats (Mammalia: Chiroptera) of the southeastern Truong Son Mountains, Quang Ngai Province, Vietnam. Journal of Threatened Taxa 8:8953-8969. DOI: httpdx.dofi.org/10.11609/jot.2785.8.7.8953-8969Webber, Q.M.R., Brigham, R.M., Park, A.D., Gillam, E.H., O'Shea, T.J., and Willis, C.K.R. 2016, Social network characteristics and predicted pathogen transmission in summer colonies of female big brown bats (Eptesicus fuscus). Behavioral Ecology and Sociobiology 70: 701-712. DOI: 10.1007/s00265-016-2093-3Woolf, A. and T. J. O'Shea. 1968. Two bighorn sheep-coyote encounters. Journal of Mammalogy 49: 770. DOI: 10.2307/1378747Woolf, A., T. J. O'Shea and D. L. Gilbert. 1970. Movements and behavior of bighorn sheep on summer ranges in Yellowstone National Park. Journal of Wildlife Management 34: 446-450. DOI: 10.2307/3799031**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- Data
Indiana Bat fecal DNA study, Indianapolis, IN Summer 2008
The endangered Indiana bat (Myotis sodalis) has declined dramatically and continuing threats have made it necessary to understand population dynamics and life history throughout the year. Specifically, demographic information (e.g., population size, reproductive success, survival) from the summer range where females raise their young in maternity colonies is difficult to estimate precisely using t
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government