Post–release Survival of Rehabilitated Brazilian Free–tailed Bats (Tadarida brasiliensis cynocephala)


  • Maena C. Voigt University of Florida



Brazilian free-tailed bat, post-release, rehabilitation, stress, wildlife


Post–release studies of post–release behavior and survival are crucial to evaluate wildlife rehabilitation efficacy. Although large numbers of animals are admitted for rehabilitation across the country, few post–release survival studies have been conducted. Post–release studies are the only way to ascertain an individual’s survival and a key variable in addressing the value of rehabilitation to wildlife populations. The goal of this study was to measure wildlife rehabilitation efficacy. One hypothesis is that capturing and handling stress negatively affects the survival of adult rehabilitated Brazilian free–tailed bats (Tadarida brasiliensis cynocephala). The second hypothesis is that injury negatively affects the survival of adult rehabilitated Brazilian free–tailed bats. In order to quantify the effects of capture, handling, and injury in rehabilitated bats the influences on survival, survival rates in three groups of bats were compared. Group one consisted of wild, healthy minimally handled bats; group two consisted of bats captive held and handled; and group three consisted of rehabilitated bats.

High transmitter loss, due to a number of factors, resulted in a small sample size. The results suggest that wildlife rehabilitation may in fact assist in the recovery, release, and survival of individual injured wildlife. There continues to be a need for carefully designed post–release studies with explicit objectives, especially for reintroductions of endangered species and/or captive bred animals.


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Author Biography

Maena C. Voigt, University of Florida

Maena C. Voigt holds a B.S. in Wildlife and Fisheries Conservation from the University of Massachusetts, Amherst, and a masters in Wildlife Ecology and Conservation from the University of Florida. She is currently interning as a Wildlife Biologist through the Environmental Careers Organization at the Bureau of Land Management in Jackson, MS.


Aldridge, H. D. J. N., and R. M. Brigham. 1988. Load carrying and maneuverability in an insectivorous bat: a test of the 5% rule of radio-telemetry. Journal of Mammalogy. 69:379–382.

Alt, G. L., and J. J. Beecham. 1984. Reintroduction of orphaned black bear cubs into the wild. Wildlife Society Bulletin. 12:169–174.

Altringham, J. D. 1999. Bats: biology and behaviour. Oxford University Press: New York, NY.

Anderson, D. W., F. Gress, and D. M. Frys. 1996. Survival and dispersal of oiled brown pelicans after rehabilitation and release. Marine Pollution Bulletin. 32:711–718.

Andrews, R. D., G. L. Storm, R. D. Philips, and R. A. Bishop. 1973. Survival and movements of transplanted red fox pups. Journal of Wildlife Management. 37:69–72.

Augee, M. L., and D. Ford. 1999. Radio-tracking studies of grey–headed flying foxes, Pteropus poliocephalus, from the Gordon Colony, Sydney. Proceedings of the Linnean Society of New South Wales. 121:61–70.

Ben–David, M., G. M. Blundell, and J. E. Blake. 2002. Post–release survival of river otters: effects of exposure to crude oil and captivity. Journal of Wildlife Management. 66:1208–1223.

Bonde, R. K., L. W. Lefebvre, L. I. Ward, E. I. Wright, and J. A. Valade. 2000. Post–release monitoring: an important aspect of the captive manatee release program. Sire News. 34:14.

Breitenmoser, U., C. Breitenmoser–Wursten, L. N. Carbyn, and S. Funk. 2001. Assessment of carnivore reintroductions. Pp. 241–281 in Carnivore Conservation (J. L. Gittleman, ed.). Cambridge University Press: Cambridge, UK.

Brewer, R., and K. R. Morris. 1984. Cross–fostering as a management tool for the Kirtland’s warbler. Journal of Wildlife Management. 48:1041–1045.

Duke, G. E., P. T. Redig, and W. Jones. 1981. Recoveries and resighting of released rehabilitated raptors. Raptor Research. 15(4):97–107.

Duke, G. E. 1987. Raptor Rehabilitation: Is it significant? Pp. 141–144 in Wildlife Rehabilitation, vol. 6 (D. J. Mackey, ed.). National Wildlife Rehabilitators Association: St. Cloud, MN.

Erickson, A. W. 1959. The age of self–sufficiency in the black bear. Journal of Wildlife Management. 23:401–405.

Estes, J. A. 1998. Concerns about the rehabilitation of oiled wildlife. Conservation Biology. 12:1156–1157.

Fenton, M. B. 2003. Science and conservation of bats: where to next? Wildlife Society Bulletin. 31:6–15.

Forman, R. T. T., and L. E. Alexander. 1998. Roads and their major ecological effects. Annual Review of Ecology and Systematics. 29:207–231.

Fraser, J. D., and M. B. Moss. 1985. Comment: A need for agency policies on wildlife rehabilitation. Wildlife Society Bulletin. 13:202–204.

Golightly, R. T., S. H. Newman, E. N. Craig, H. R. Carter, and J. A Mazet. 2002. Survival and behavior of western gulls following exposure to oil and rehabilitation. Wildlife Society Bulletin. 30:539–546.

Hartup, B. K. 1996. Rehabilitation of native reptiles and amphibians in DuPage County, Illinois. Journal of Wildlife Diseases. 32:109–112.

Horton, R. H. 1987. Public education by the National Wildlife Rehabilitators Association: a survey report. Pp. 127–140 in Wildlife Rehabilitation, vol 6, (D. J. Mackey, ed.). National Wildlife Rehabilitators Association: St. Cloud, MN.

Jessup, D. A. 1998. Rehabilitation of oiled wildlife. Conservation Biology. 12:1153–1155.

Jung, T. S., I. D. Hickey, and R. D. Dunne. 2002. Apparent capture myopathy in hoary bats (Lasiurus cinereus): a cautionary note. Canadian Field Naturalist. 116:136–137.

Karesh, W. B. 1995. Wildlife rehabilitation: additional considerations for developing countries. Journal of Zoo and Wildlife Medicine. 26:2–9.

Lander, M. E., J. T. Harvey, K. D. Hanni, and L .E. Morgan. 2002. Behavior, movements, and apparent survival of rehabilitated and free–ranging harbor seal pups. Journal of Wildlife Management. 66:19–28.

Lollar, A., and B. Schmidt–French. 1998. Captive care and medical reference for the rehabilitation of insectivorous bats. Bat World Publication: Mineral Wells, TX.

Ludwig, D. R., and S. M. Mikolajczak. 1985. Post–release studies: a review of current information. Pp. 111–124 in Wildlife Rehabilitation, vol. 4 (P. Beaver, ed.). National Wildlife Rehabilitators Association: St. Cloud, MN.

Lunney, D., S. Gresser, P. Mahon, and A. Matthews. 2004. Post–fire survival and reproduction of rehabilitated and unburnt koalas. Biological Conservation. 120:567–575.

Marion, W. R. 1989. Wildlife Rehabilitation: Its role in future resource management. Transactions of the 54th North American Wildlife and Natural Resource Conference. Pp. 476–482.

Martell, M. S., P. T. Redig, J. Nibe, and G. Buhl. 1991. Survival and movements of released rehabilitated bald eagles. Journal of Raptor Research. 25:72– 76.

Marti, C. D., and P. W. Wagner. 1980. Successful release of captive barn owls. Raptor Research. 14:61–62.

Mech, L. D., U. S. Seal, and S. M. Arthur. 1984. Recuperation of a severely debilitated wolf. Journal of Wildlife Diseases. 20:166–168.

Nawojchik, R., D. J. St. Aubin, and A. Johnson. 2003. Movements and dive behavior of two stranded, rehabilitated long finned pilot whales (Globicephala melas) in the northwest Atlantic. Marine Mammal Science. 19:232–239.

Nesbitt, S. A., and J. W. Carpenter. 1993. Survival and movements of greater sandhill cranes experimentally released in Florida. Journal of Wildlife Management. 57:672–679.

Postupalsky, S., and J. B. Holt, Jr. 1975. Adoption of nestlings by breeding Bald Eagles. Raptor Research. 9:18–20.

Saba, V. S., and J. R. Spotila. 2003. Survival and behavior of freshwater turtles after rehabilitation from an oil spill. Environmental Pollution. 126:213–223.

Sharp, B. E. 1996. Post-release survival of oiled, cleaned seabirds in North America. Ibis. 138:222– 228.

Steinhart, P. 1990. Humanity without biology.Audubon Magazine. 92:24–27.

Wilkins, K. T. 1989. Tadarida brasiliensis in Mammalian Species Accounts. 331:1–10. American Society of Mammalogists. <>.




How to Cite

Voigt, M. (2006). Post–release Survival of Rehabilitated Brazilian Free–tailed Bats (Tadarida brasiliensis cynocephala). Wildlife Rehabilitation Bulletin, 24(2), 19–26.