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Christopher Yahnke


I am interested in questions that address both basic and applied biology. My first independent research project as an undergraduate at the University of Wisconsin-Milwaukee looked at the effects of migratory waterfowl on the chemistry and biology of an urban lagoon. I found that the lagoon was heavily impacted by road salt but little impacted by nitrogenous waste from the waterfowl. At the same time, I collected data on gull predation by peregrine falcons released into downtown Milwaukee. This led to a seasonal job in the Green Mountains of Vermont with the U.S. Forest Service studying the impact of hikers on the nesting behavior of peregrine falcons. This exposure to research early in my career was vital to my success in the profession of biology, and I urge all undergraduate students to conduct an independent study as an integral part of their college experience.

My graduate work focused on the systematics and ecology of neotropical mammals. I’ve utilized molecular techniques to extract and amplify DNA from museum specimens of rare and extinct foxes to better understand their systematic relationships. In the early 1990s, there were only a few labs working on “ancient DNA” and I was fortunate to work in the lab of Dr. Robert Wayne, a leader in the molecular systematics of canids, at UCLA. We were able to clarify the taxonomic position of Darwin’s fox as a distinct species endemic to Chile. While living in the Paraguayan chaco, my wife and I also worked on a captive breeding project of chacoan peccaries for the Zoological Society of San Diego. Some of the animals we cared for, as well as their offspring, are now living at the Phoenix Zoo, the San Diego Zoo, and most recently the Saint Louis Zoo.

My dissertation research focused on how small mammal communities are structured in agricultural, successional, and natural habitats in the central Paraguayan chaco. I investigated the population ecology of the vesper mouse (Calomys laucha) and its associated hantavirus Laguna Negra Virus. My results show that populations of vesper mice grow throughout the dry season and that this is associated with a higher incidence of viral infection. Further, seroprevelance is higher in agricultural and successional habitats. This has clear implications for the transmission of the virus to humans. I have also observed that seroprevelence increases as the relative frequency of the rodent reservoir increases in the community.

Experience and Interests

Teaching Experience

  • Professor, Division of Wildlife, University of Wisconsin – Stevens Point (September 2020-Present)
  • Professor, Department of Biology, University of Wisconsin – Stevens Point (2013-2020)
  • Associate Professor, Department of Biology, University of Wisconsin – Stevens Point (2007-2013)
  • Assistant Professor,  Department of Biology, University of Wisconsin – Stevens Point (2001-2007)
  • Assistant Professor, Department of Biology, Clarke University (1999-2001)

Professional Experience

  • Co-founder, Innovative Thermal Management Technologies (ITMT), San Diego, CA (2016-2018)
  • Visiting Scientist, University of California San Diego (2015-2017)
  • Environmental Engineer, Iranian Gas Engineering & Development Company (IGEDC), Tehran, Iran (2009-2010)
  • Senior process engineer, Pilab Company, Tehran, Iran (2007-2009)
  • Research Assistant, Biochemical and Bioenvironmental Research Center, Sharif University of Technology, Tehran, Iran (2005-2007)

Research Interests

  • Community ecology of bats and small mammals
  • Museum Science
  • Science Education



  • Program Review Committee (2016-Present)
  • UWSP faculty representative, UW-System Women and Science Program Board (2007-2015)
  • University Professional Development Committee (2007-2013)


  • Bioblitz, Milwaukee Public Museum (2015-Present)
  • Bioblitz, Urban Ecology Center and Door County Land Trust (2018-Present)

Professional Memberships

  • American Society of Mammalogists, Public Education Committee (2011-Present)
  • Citizen Science Association (2017-Present)
  • Society for Integrative and Comparative Biology (2021)



Select Publications

2019 – Moscarella, R.A., S.M.G. Hoffman, P. Myers, C.J. Yahnke, and B.L. Lundrigan. Genetic and demographic analysis of invasive Peromyscus leucopus in the northern Great Lakes region. Journal of Mammalogy, 100(2):345-353.

2015 – Stevens, R.B., K.H. Karau, C.J. Yahnke, S.R. Wendt, and R.J. Rowe. Dead mice can grow – variation of standard external mammal measurements from live and three postmortem body states.  Journal of Mammalogy, 96(1):185-193.

2013 – Yahnke, C.J., T. Dewey, and P. Myers. Animal Diversity Web as a teaching & learning tool to improve research & writing skills in college biology courses. American Biology Teacher, 75(7):494-498.

Yahnke, C.J. Why grow Big?  Classroom Quaarvark activity, University of Michigan available online at

Yahnke, C.J. Carnivores of India.  Classroom Quaarvark activity, University of Michigan available online at

2011 – Long, C.A. and C.J. Yahnke. The end of the Pleistocene: Elk-moose and caribou in Wisconsin.  Journal of Mammalogy, 92(5):1127-1135.

2006 – Yahnke, C.J., Habitat use and natural history of small mammals in the central Paraguayan Chaco. Mastozoologia Neotropical, 13(1):103-116.

2006 – Yahnke, C.J., Testing Optimal Foraging Theory Using Bird Predation on Goldenrod Galls. American Biology Teacher, 68(8):464-467. (Accepted April, 2004)

2001 – Yahnke, C.J., P.L. Meserve, T.G. Ksiazek, and J.N. Mills. Patterns of infection with Laguna Negra virus in wild populations of Calomys laucha in the central Paraguayan chaco. American Journal of Tropical Medicine and Hygiene, 65(6):768-776.

1998 – Yahnke, C.J., I. Gamarra de Fox, and F. Colman. Mammalian species richness in Paraguay: the effectiveness of national parks in preserving biodiversity. Biological Conservation 84:263-268.

1997 – Yahnke, C.J., J. Unger, B. Lohr, D.A. Meritt, and W. Heuschele. Age specific fecundity, litter size, and sex ratio in the chacoan peccary (Catagonus wagneri). Zoo Biology 16:301-307.

1996 – Yahnke, C.J., W.E. Johnson, E. Geffen, D. Smith, F. Hertel, M.S. Roy, C.F. Bonacic, T.K. Fuller, B. Van Valkenburgh, and R.K. Wayne. Darwin’s fox: a distinct endangered species in a vanishing habitat. Conservation Biology 10:366-375.

1995 – Yahnke, C.J., Metachromism and the insight of Wilfred Osgood: evidence of common ancestry for Darwin’s fox and the Sechura fox. Revista Chilena de Historia Natural 68:459-467.

Fun Facts

Best advice you ever received?

You can’t be in the right place at the right time if you don’t go anywhere.

What did you want to be when you were growing up?

A zookeeper at the Milwaukee Public Zoo

Favorite quote?

“Chance favors the prepared mind.” – Louis Pasteur

One thing about your college that you are most proud of?

I have never met a group of people that loves their students more and works to build them up.  I also love how we support each other professionally – it really does feel like a family.

What do you enjoy most about teaching?

The thing I most enjoy about teaching is learning.

A piece of advice for students?

College is a four-year job interview.  Every day you will have the opportunity to work on marketable skills, whether in the classroom or in the field.

Christopher Yahnke
Professor of Wildlife
Coordinator of Wildlife Discipline
Curator of Birds and Mammals, UW-Stevens Point Museum of Natural History
College of Natural Resources

346 Trainer Natural Resources


Ph.D. Biology
Northern Illinois University

M.S. Biology
Northern Illinois University

B.S. Zoology
University of Wisconsin-Milwaukee


Field Ecology of Hawaii
Carnivore Ecology
Conservation Biology