Rachel Santymire, Ph.D.


Conservation & Science


Adjunct Scientist


Ph.D. – Environmental Science and Policy, George Mason University
M.S. – Animal Physiology, Clemson University
B.S. – Animal Industries: Pre-veterinary Science, Clemson University


Areas of Expertise

  • Reproductive physiology
  • Stress physiology
  • Conservation biology
  • Evolutionary biology of reproductive processes
  • Evolutionary biology of stress adaptation
  • Ecosystem health
  • Small population biology


Never quite fitting into the field of animal production science, Rachel began her career thinking about how to adapt techniques designed for domestic species to conserving wildlife. While everyone was researching livestock production, she was traveling to zoos to collect samples to characterize wildlife reproductive biology. Increasing the knowledge of basic reproductive processes and the evolutionary biology of these traits has been one of Rachel’s interests throughout her career.

Rachel founded Lincoln Park Zoo’s endocrinology program. As Rachel says, “The motto of our program is, ‘If it defecates, we will study it!’” The mission of her research is to promote better scientific understanding of the basic biology of wildlife, including evolutionary and ecological processes, and gain knowledge of the relationship among an animal’s physiology, behavior, and environment using non-invasive methods.

One of Rachel’s specialties is designing methods for the field. She has developed techniques that can be used in remote locations with limited resources. Rachel also designs methods for those elusive poopers. Her “frog swabs” method allows scientists to learn more about amphibian endocrinology by simply swabbing their skin. Rachel is also passionate about mentoring the next generation of scientists and science enthusiasts. She has faculty appointees at several universities, including the University of Chicago; University of Illinois at Chicago; and DePaul University.

In her most recent position at the zoo, Rachel led the Davee Center for Endocrinology and Epidemiology, which was retired as a center in 2020. Rachel remains an adjunct scientist with the zoo.


  • Merrill, L., Ospina, E. A., Santymire, R. M., & Benson, T. J. 2020. Egg Incubation Temperature Affects Development of Innate Immune Function in Nestling American Robins (Turdus migratorius). Physiological and Biochemical Zoology, 93(1), 1–12. https://doi.org/10.1086/705361.
  • Murray, M. J., Young, M. A., & Santymire, R. M. 2020. Use of the ACTH challenge test to identify the predominant glucocorticoid in the southern sea otter (Enhydra lutris nereis). Conservation Physiology, 8(1). https://doi.org/10.1093/conphys/coz116.
  • Potratz, E. J., Brown, J. S., Gallo, T., Anchor, C., & Santymire, R. M.   2019. Effects of demography and urbanization on stress and body condition in urban white-tailed deer. Urban Ecosystems, Early View. https://doi.org/10.1007/s11252-019-00856-8.
  • Santymire, R. M., Lonsdorf, E. V., Lynch, C. M., Wildt, D. E., Marinari, P. E., Kreeger, J. S., & Howard, J. G. 2019. Inbreeding causes decreased seminal quality affecting pregnancy and litter size in the endangered black-footed ferret. Animal Conservation, 22(4), 331–340. https://doi.org/10.1111/acv.12466.
  • Santymire, R. M., Manjerovic, M. B., & Sacerdote-Velat, A. 2018. A novel method for the measurement of glucocorticoids in dermal secretions of amphibians. Conservation Physiology, 6(1). https://doi.org/10.1093/conphys/coy008.
  • Schell, C. J., Young, J. K., Lonsdorf, E. V., Mateo, J. M., & Santymire, R. M. 2018. It takes two: Evidence for reduced sexual conflict over parental care in a biparental canid. Journal of Mammalogy, 99(1), 75–88. https://doi.org/10.1093/jmammal/gyx150.
  • Murray, C. M., Stanton, M. A., Wellens, K. R., Santymire, R. M., Heintz, M. R., & Lonsdorf, E. V. 2018. Maternal effects on offspring stress physiology in wild chimpanzees. American Journal of Primatology, 80(1), n/a-n/a. https://doi.org/10.1002/ajp.22525.
  • Buxton, V. L., Santymire, R. M., & Benson, T. J.   2018. Mixed effects of urbanization on density, nest survival, and nestling corticosterone of a generalist passerine. Ecosphere, 9(12), e02517. https://doi.org/10.1002/ecs2.2517.
  • Schell, C. J., Young, J. K., Lonsdorf, E. V., Santymire, R. M., & Mateo, J. M.   2018. Parental habituation to human disturbance over time reduces fear of humans in coyote offspring. Ecology and Evolution, Early View. https://doi.org/10.1002/ece3.4741.
  • Jacobson, S. L., Freeman, H. D., Santymire, R. M., & Ross, S. R. 2017. Atypical experiences of captive chimpanzees (Pan troglodytes) are associated with higher hair cortisol concentrations as adults. Royal Society Open Science, 4(12), 170932. https://doi.org/10.1098/rsos.170932.
  • Schell, C. J., Young, J. K., Lonsdorf, E. V., Mateo, J. M., & Santymire, R. M. 2017. Investigation of techniques to measure cortisol and testosterone concentrations in coyote hair. Zoo Biology. https://doi.org/10.1002/zoo.21359.
  • Eckardt W, Stoinski TS, Rosenbaum S, Umuhoza MR, & Santymire R. 2016. Characterizing stress physiology in Virunga mountain gorillas. Conservation Physiology, 4, cow029.
  • Santymire, R. M., Misek, S., Gossett, J., Kamhout, M., Chatroop, E., & Rafacz, M. 2016. Male behaviours signal the female’s reproductive state in a pair of black rhinoceros housed at Lincoln Park Zoo. Journal of Zoo and Aquarium Research, 4(1), 30–37.
  • Schell, C. J., Young, J. K., Lonsdorf, E. V., Mateo, J. M., & Santymire, R. M. 2016. Olfactory attractants and parity affect prenatal androgens and territoriality of coyote breeding pairs. Physiology & Behavior, 165, 43–54. http://doi.org/10.1016/j.physbeh.2016.06.038.
  • Sacerdote-Velat A, Manjerovic MB, and Santymire R. 2016. Preliminary survey of Batrachochytrium dendrobatidis occurrence on an urban-rural gradient in the Chicago region of Illinois, USA. Herpetological Review 47(1): 57-58.
  • Howard, J. G., Lynch, C., Santymire, R. M., Marinari, P. E., & Wildt, D. E. 2016. Recovery of gene diversity using long-term cryopreserved spermatozoa and artificial insemination in the endangered black-footed ferret. Animal Conservation, 19(2), 102–111.
  • Freeman, E.W., J. M. Meyer, J. Bird, J. Addendorf, B. A. Schulte, R. M. Santymire. 2014. Impacts of environmental pressures on the reproductive health of subpopulations of black rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa. Conservation Physiology 2:Doi:10.1093/conphys/cot034.
  • Freeman, E.W., J. M. Meyer, J. Addendorf, B. A. Schulte, R. M. Santymire.  2014. Age and fecal gonadal metabolite concentrations affect scraping behavior of black rhinoceros (Diceros bicornis bicornis) in Addo Elephant National Park, South Africa. Journal of Mammalogy 95:340-348.
  • Chosy, J., Wilson, M., & Santymire, R. 2014. Behavioral and physiological responses in felids to exhibit construction. Zoo Biology, 33(4), 267–274. https://doi.org/10.1002/zoo.21142.
  • Jacobs RM, Ross SR, Wagner KE, Leahy M, Meiers ST, Santymire RM 2014. Evaluating the physiological and behavioral response of a male and female gorilla (Gorilla gorilla gorilla) during an introduction. Zoo Biology, 33(5), 394–402.
  • Reichert-Stewart, J., R. M. Santymire, D. Armstrong, T. M. Harrison and J. R. Herrick. 2014. Fecal endocrine monitoring of reproduction in female snow leopards (Uncia uncia). Theriogenology 82:17-26.
  • Markham, A.C., R.M. Santymire, E.V. Lonsdorf, M.R. Heintz, I. Lipende, and C.M. Murray.  2014. Rank Effects on Social Stress in Lactating Chimpanzees. Animal Behaviour 87:195-202.
  • Santymire, R.M., H. Branvold-Faber and P.E. Marinari. 2014. Recovery of the Black-Footed Ferret. In: Biology and Diseases of the Ferret 3rd Edition (J.G. Fox and R.P. Marini, eds.). John Wiley and Sons, Inc.: 219-231.
  • Hunt, V., Magle, S., Vargas, C., Brown, A., Lonsdorf, E., Sacerdote, A., Sorley, E., Santymire, R. 2014. Survival, abundance, and capture rate of eastern cottontail rabbits in an urban park. Urban Ecosystems 17(2): 547-560.
  • Daudi, M., R. Santymire, F. Lankester and J. Buza. 2014. The impact of malignant catarrhal fever virus challenge on physiological stress in cattle. American Journal of Research Communication 2(3):13-29.
  • Rafacz, M. and R. Santymire. 2014. Using odor cues to elicit a behavioral and hormonal response in zoo-housed African wild dogs. Zoo Biology 33:144-149.
  • Rafacz, M., Margulis, S., Santymire, R. 2013. Hormonal and behavioral patterns of reproduction in female hylobatids. Animal Reproduction Science 137(1-2): 103-112.
  • Armstrong, D. and Santymire, R.M. 2013. Hormonal and behavioral variation in pied tamarins housed in different management conditions. Zoo Biology 32(3): 299-306.
  • Howell-Stephens, J., Bernier, D., Brown, J., Mulkerin, D., Sanytmire, R.M. 2013. Using non-invasive methods to characterize gonadal hormonal patterns of southern three-banded armadillos (Tolypeutes matacus) housed in North Americans zoo. Animal Reproduction Science 138:314-323.
  • Schell, C.J, J.M. Young, E.V. Lonsdorf and R.M. Santymire. 2013. Validating the use of non-invasive techniques to monitor stress responses in coyotes (Canis latrans). Journal of Mammalogy 94(5):1131-1140.
  • Murray, C.M., Heintz, M.R., Lonsdorf, E.V., Parr, L.A. and Santymire, R.M. 2013. Validation of a field technique and characterization of fecal glucocorticoid metabolite analysis in wild chimpanzees (Pan troglodytes). American Journal of Primatology 75(1):57-64.
  • Ganswindt, A., Brown, J., Freeman, E., Kouba, A., Penfold, L., Santymire, R., Vick, M., Wielebnowski, N., Willis, E. and Milnes, M. 2012. . International Society for Wildlife Endocrinology: the future of endocrine measures for reproductive science, animal welfare, and conservation biology. Biology Letters. doi: 10.1098/rsbl.2011.1181.
  • Santymire, R.,  E.W. Freeman, E. Lonsdorf, M. Heintz, and D. Armstrong. 2012. Assessment of adrenocortical activity after ACTH challenge in diverse African wildlife species. International Journal of Animal and Veterinary Advances 4(2): 99-108.
  • Howell-Stephens, J., Bernier, D., Brown, J., Mulkerin, D., and Santymire, R.M. 2012. Characterizing adrenocortical activity in zoo-housed southern three-banded armadillos (Tolypeutes matacus). General and Comparative Endocrinology 178(1): 64-74.
  • Santymire, R.M., Meyer, J., and Freeman, E.W. 2012. Characterizing Sleep Behavior of the Wild Black Rhinoceros (Diceros bicornis bicornis). Sleep 35(11):1569-1574.
  • Adkin, A., D. Bernier and R.M. Santymire. 2012. Characterizing the reproductive biology and behavior of the zoo-housed Sichuan takin (Budorcas taxicolor tibetana) using non-invasive techniques. Theriogenology 78: 483-494.
  • Rafacz, M., S. Margulis, and R. Santymire. 2012. Hormonal Correlates of Paternal Care in Three Hylobatid Species. American Journal of Primatology 74(3): 247-260.
  • Santymire, R.M., S.M. Wisely, T.M. Livieri and J.G. Howard. 2012. Using canine width to determine age in the black-footed ferret Mustela nigripes.. Small Carnivore Conservation 46:17-21, June Issue.
  • Melber, L., R.M. Santymire, and R. Bergren. 2011. Beyond Borders: Zoo as Training Location for Wildlife Biologists. Journal of Museum Education 36(1): 29-43..
  • Melber, L., Santymire, R.M. and Bergren, R. 2011. Beyond Borders: Zoo as Training Location for Wildlife Biologists. Journal of Museum Education 36(1): 29-43.
  • Poessel, S. D. Biggins, R. Santymire, T. Livieri, K. Cooks and L. Angeloni. 2011. Environmental enrichment affects adrenocortical stress responses in the endangered black-footed ferret. General and Comparative Endocrinology 172:526-533.
  • Loeding, E., D. Bernier, J. Thomas and R.M. Santymire. 2011. Investigating the impacts of a female to female introduction on hormone levels in the sable antelope (Hippotragus niger). Journal of Applied Animal Welfare Science 14: 220-246.
  • Santymire, R.M., J.L. Brown, R.C. Santymire, R.A. Bauer, D.E. Wildt, J.G. Howard. Online. 2011. Reproductive gonadal activity in the fishing cat (Prionailurus viverrinus) assessed by fecal steroid analyses. Animal Reproduction Science.
  • Fuller, G., Margulis, S.W. and Santymire, R. 2011. The effectiveness of indigestible markers for identifying individual animal feces and their prevalence of use in North American zoos. Zoo Biology 30(4):379-398.
  • Fuller, G., S.W. Margulis, and R.Santymire. 2011. The effectiveness of indigestible markers for identifying individual animal feces and their prevalence of use in North American zoos. Zoo Biology 30(4):379-398.
  • Heintz, M.R., Santymire, R.M., Parr, L.A., Lonsdorf, E.V. 2011. Validation of cortisol enzyme immunoassay and characterization of salivary cortisol circadian rhythm in chimpanzees (Pan troglodytes). American Journal of Primatology, 73: 1-6.
  • Santymire, R.M., Fa, J.E., Funk, S.M., O’Connell, D. 2011. Zoo Conservation Biology. Zoo Biology 31(1): 117-118.
  • Santymire, R.M., and Armstrong, D. 2010. Development of a field-friendly technique for fecal steroid extraction and storage using the African wild dog (Lycaon pictus). Zoo Biology, 28, 1-14.
  • Rafacz, M., Margulis, S., and Santymire, R. 2009. Comparing the role of androgens in paternal care between gibbon species. Gibbon Journal 5: 74-80.
  • Wisely, S.M., Howard, J.G., Williams, S.A., Bain, O., Santymire, R.M., Bardsley, K.D., and Williams, E.S. 2008. An unidentified filarial species and its impact on fitness in wild populations of the black-footed ferret (Mustela nigripes). Journal of Wildlife Diseases 44(1):53-64.
  • Wisely, S.M., Santymire, R.M., Livieri, T.M., Mueting, S.A., Wildt, D.E., and Howard, J.G. 2008. Genotypic and phenotypic consequences of reintroduction history: case study of the black-footed ferret. Conservation Genetics 9(2):389-399.
  • Santymire, R.M., P.E. Marinari, J.S. Kreeger, D.E. Wildt and J.G. Howard. 2007. Slow Cooling Prevents Cold-Induced Damage to Sperm Motility and Acrosomal Integrity in the Black-Footed Ferret (Mustela nigripes). Reproduction, Fertility and Development 19:652-663.
  • Pukazhenthi, B., R. Santymire, A. Crosier, J.G. Howard, D. E. Wildt. 2006. Challenges in cryopreserving endangered mammal spermatozoa: morphology and the value of acrosomal integrity as markers of cryo-survival. Spermatology. Soc Reprod Fertil Suppl, Nottingham: Nottingham Press, 65:433-446.
  • Santymire, R.M., Marinari, P.E., Kreeger, J.S., Wildt, D.E., and Howard, J.G.  2006. Determining semen osmolality and effect of medium osmolality on sperm viability in the black-footed ferret (Mustela nigripes). Cryobiology 54:37-50.
  • Howard, J.G., R.M. Santymire, P.E. Marinari, J.S. Kreeger, L. Williamson and D.E. Wildt. 2006. Use of reproductive technology for black-footed ferret recovery. In: Recovery of the Black-Footed Ferret: Progress and Continuing Challenges (Eds., J.E. Roelle, B.J. Miller, J.L. Godbey and D.E. Biggins.). pp. 28-36. U.S. Geological Survey Scientific Investigations Report 2005-5293, Reston, VA.
  • Wisely, S.M., Santymire, R.M., Livieri, T.M., Marinari, P.E., Kreeger, J.S., Wildt, D.E. and Howard, J.G. 2005. Environment influences morphology and development for in situ and ex situ populations of the black-footed ferret (Mustela nigripes). Animal Conservation, 8: 321-328.
  • Brown, J.L., Goritz, F., Pratt-Hawkes, N. Hermes, R., Galloway, M., Graham, L.H., Gray, C., Walker, S.L., Gomez, A., Moreland, R., Murray, S., Schmitt, D.L., Howard, J.G., Lehnhardt, J., Beck, B., Bellem, A., Montali, R. and Hildebrandt, T.B. 2004. Successful artificial insemination of an Asian elephant at the National Zoological Park. Zoo Biology, 23: 45-63.
  • Terio, K.A., Brown, J.L., Moreland, R. and Munson, L. 2002. Comparison of different drying and storage methods on quantifiable concentrations of fecal steroids in the cheetah. Zoo Biology, 21: 215-222.
  • Moreland, R.B., Richardson, M.E., Lamberski, N. and Long, J.A. 2001. Characterizing the reproductive physiology of the male southern black howler monkey, Alouatta caraya. Journal of Andrology, 22(3): 395-403.