Franziska Sandmeier

My research interests are at the intersection of ecology, comparative immunology, wildlife disease, and conservation biology. I primarily focus on reptile conservation and immunology. In the past, I have worked extensively with Mojave Desert Tortoises, with current projects focused on temperature-dependence of cellular immune responses. The lab is also focused on the ecology and conservation of reptiles in Colorado, including ornate box turtles and Colorado checkered whiptails.

Research Positions:

 If you are interested in conducting research my lab as an undergraduate, a 3+ 2 student (see Department page for detail), or a MS student, contact me through email.

 Click here for a list of past publications, as well as current and future research directions.

Director of the Wildlife and Natural Resources Program

Faculty Advisor for Tribeta Biology Honors Society

Sandmeier, F.C., K. Olson, A. Martin, and T. Urban. 2025. Memory responses to ovalbumin-immunization in Mojave desert tortoises. Developmental and Comparative Immunology, 105322.

Tracy, C. R., M. R. Gordon, E. T. Simandle, M. L. Forester, M. Beck, F. C. Sandmeier, B. E. Hagerty, R. N. Fisher, P. M. Noles. 2024. The Bufo boreas complex in the Great Basin, USA. Box 6 in: Olson, D.H. and D.S. Pilliod, Amphibians of the US West: Biogeography, Diversity, Threats, and Conservation Actions. Chapter 11 in: Dodd, C.K, Jr., H. Heatwole, and S. King (eds.). Amphibian Biology, Volume 9: Status of Conservation and Decline of Amphibians in the Western Hemisphere, Part 7, Canada and the United States.

Sandmeier, F.C. 2024. Quantification of thermal acclimation in immune functions in ectothermic animals. Biology 13:179.

Sandmeier, F.C. 2024. Recent advances in understanding the immune system of reptiles. Encyclopedia of Immunobiology, 2e. doi:10.1016/B978-0-128-24465-4.00038-7.

Sandmeier, F.C., J. Morales, M. Gomez, M. Kester, K. Gann-Archuleta, C. Crooker, J.M. Goessling, C.R. Tracy, and C.L Weitzman. 2023. Ecoimmunological differences among congeneric tortoises in the United States. Journal of Zoology. 321:237-248.

Bauschlicher, S.N., C.L. Weitzman, V. Martinez, C.R. Tracy, D. Alvarez-Ponce, and F.C. Sandmeier. 2023. Assessing spatial distribution, genetic variants, and virulence of pathogen Mycoplasma agassizii in threatened Mojave desert tortoises. Ecology and Evolution 6:e10173.

Slama, S.L., G.S. Williams, M.N. Painter, M.D. Sheedy, and F.C. Sandmeier. 2022. Temperature and season influence phagocytosis by B1 lymphocytes in the Mojave desert tortoise. Integrative and Comparative Biology. doi: 10.1093/icb/icac025

Sandmeier, F.C., K.L. Leonard, C.L. Weitzman, and C.R. Tracy. accepted. Potential facilitation between a commensal and pathogenic microbe in a wildlife disease. Ecohealth 19:427-438.

Peterson, E.K., C.D. Jones, F.C. Sandmeier, A.P. Arellano Rivas, C.A. Back, A. Canney, J. Fender, M. Gomez, J. Gorski, N. Heintzelman, K. Healey, M. Kester, D. Klinger, A. Liao, C.W. Varian-Ramos, B. Vanden Heuvel. 2021. Drought influences biodiversity in a semi-arid shortgrass prairie in southeastern Colorado. Journal of Arid Environments 195:104633.

Weitzman, C.L., B.E. Hagerty, F.C. Sandmeier, and C.R. Tracy. 2021. Desert tortoises in Zion National Park represent natural extension of eastern distribution. Chelonian Conservation and Biology 20:91-96

Slama, S.L., M.N. Painter, M.D. Sheedy, and F.C. Sandmeier. 2021. Quantifying phagocytic lymphocytes in ectothermic vertebrates: a simplified technique for assessing immune function. Methods in Ecology and Evolution 12:548-552.

Luzuriaga-Neira, A., F.C. Sandmeier, C.L. Weitzman, C.R. Tracy, S.N. Bauschlicher, R.L. Tillet, and D. Alvarez-Ponce. 2021. Mycoplasma agassizii, an opportunistic pathogen of tortoises, shows very little genetic variation across the Mojave and Sonora Deserts. PLOS ONE 2:30245895.

Gordon, M.R., E.T. Simandle, F.C. Sandmeier, and C.R. Tracy. 2020. Two new cryptic endemic toads of Bufo discovered in central Nevada, Western United States (Amphibia: Bufonidae: Bufo (Anaxyrus)). Copeia 108:166-183.

Sandmeier, F.C., R. Ruiz, K.L. Leonard, B. Bayer, C. Dowd, and T. Urban. 2019. A quantitative PCR assay for a mycoplasma from emydid turtles indicates high prevalence in healthy three-toed box turtles (Terrapene carolina triunguis) from Missouri, USA. Journal of Wildlife Diseases 55:589-596.

Sandmeier, F.C., K.L. Leonard, C.R. Tracy, K.K. Drake, T.E. Esque, K. Nussear, and J.M. Germano. 2019. Tools to understand seasonality in health: quantification of microbe loads and analyses of compositional ecoimmunological data reveal complex patterns in tortoise populations. Canadian Journal of Zoology 97:841-848.

Goessling, J.M., C. Guyer, J.C. Godwin, S.M. Herman, F.C. Sandmeier, L.L. Smith, and M.T. Mendonça. 2019. Upper respiratory tract disease and associated diagnostic tests of mycoplasmosis in Alabama populations of the Gopher tortoises, Gopherus polyphemus. PLoS ONE 14:e0214845.

Weitzman, C.L., F.C. Sandmeier, and C.R. Tracy. 2018. Host species, pathogens, and disease associated with divergent nasal microbial communities in tortoises. Royal Society Open Science 5:161086.

Sandmeier, F.C., C.L. Weitzman, and C.R. Tracy. 2018. An ecoimmunological approach to disease in tortoises reveals the importance of lymphocytes. Ecosphere 9:e02427.

Weitzman, C.L., R.L. Tillett, F.C. Sandmeier, C.R. Tracy, and D. Alvarez-Ponce. 2018. High quality draft genome sequence of Mycoplasma testudineum strain BH29T, isolated from the respiratory tract of a desert tortoise.
Standards in Genomic Sciences 13:9. 10.1186/s40793-018-0309-z.

Alvarez-Ponce, D., C.L. Weitzman, R.L. Tillett, F.C. Sandmeier, and C.R. Tracy. 2018. High quality draft genome sequences of Mycoplasma agassizii strains PS6T and 723 isolated from Gopherus tortoises with upper respiratory tract disease. Standards in Genomic Sciences 13:12.

Sandmeier, F.C., N.K. Maloney, C.R. Tracy, D. Hyde, H. Mohammadpour, R. Marlow, S. DuPré, and K. Hunter. 2017. Chronic disease in the Mojave desert tortoise: host physiology and recrudescence obscure patterns of pathogen transmission. Ecology and Evolution 7:10616-10629. DOI 10.1002/ece3.3480.

Weitzman, C.L., R. Gov, F.C. Sandmeier, S. Snyder, and C.R. Tracy. 2017. Co-infection does not predict disease signs in Gopherus tortoises. Royal Society Open 4:171003.

Weitzman, C.L. F.C. Sandmeier, and C.R. Tracy. 2017. Prevalence and diversity of the upper respiratory pathogen Mycoplasma agassizii in Mojave desert tortoises (Gopherus agassizii). Herpetologica 73:113-120.

Sandmeier, F.C., C.L. Weitzman, K.N. Maloney, C.R. Tracy, N. Nieto, M.B. Teglas, K.W. Hunter, S. DuPré, C.M. Gienger, and M.W. Tuma. 2017. Comparison of current methods for the detection of chronic mycoplasmal URTD in wild populations of the Mojave desert tortoise (Gopherus agassizii). Journal of Wildlife Disease 53:91-101.

Sandmeier, F.C., K.R. Horn, and C.R. Tracy. 2016. Temperature-independent, seasonal fluctuations in immune function of the Mojave Desert Tortoise (Gopherus agassizii). Canadian Journal of Zoology 95:583-590.

 Sandmeier, F.C. and C.R. Tracy. 2014. The metabolic pace-of-life model: incorporating ectothermic organisms into the theory of vertebrate ecoimmunology. Integrative and Comparative Biology. doi:10.1093/icb/icu21.

Sandmeier, F.C., C.R. Tracy, B. Hagerty, S. DuPré, H. Mohammedopour, K.W. Hunter. 2013. Mycoplasmal upper respiratory tract disease across the range of the threatened Mojave desert tortoise: associations with thermal regime and natural antibodies. EcoHealth 10:63-71.

DuPré, S.A., C.R. Tracy, F.C. Sandmeier, K.W. Hunter. 2012. Quantitative PCR method for Pasteurella testudinis DNA in nasal lavage samples from the desert tortoise (Gopherus agassizii). Journal of Microbiological Methods 91:443-447.

Sandmeier, F.C., C.R. Tracy, S. DuPré, K.W. Hunter. 2012. A trade-off between natural and acquired antibody production in a reptile: implications for long-term resistance to disease. Biology Open. doi:10-1242/bio.20122527

Sandmeier, F.C., C. R. Tracy, S. DuPré, H. Mohammadpour, K.W. Hunter. 2011. URTD (upper respiratory tract disease), mycoplasmosis, and antibody-responses in the Mojave desert tortoise. Science Newsletter, Mojave National Preserve 1:8-13.

Sandmeier, F.C., C.R. Tracy, S. DuPré, K.W. Hunter. 2009. Upper respiratory tract disease (URTD) as a threat to desert tortoise populations: a reevalutation. Biological Conservation 142:1255-1268

Hunter, K.W., Jr., S,A. DuPré, T. Sharp, F.C. Sandmeier, C.R. Tracy. 2008. Western blot can distinguish natural and acquired antibodies to Mycoplasma agassizii in the desert tortoise (Gopherus agassizii). Journal of Microbiological Methods 75: 464-471.