Clay Nielsen | College of Agricultural Sciences | SIU

Southern Illinois University



Clay Nielsen, Ph.D.

Professor, Forestry

Clay Nielsen
Phone: 618 | 453-7474
Location: Agriculture Building, 186-C
CV: nielsen-2p-cv

Dr. Clay Nielsen is Professor of Wildlife Ecology and Conservation in the Department of Forestry and Cooperative Wildlife Research Laboratory at Southern Illinois University, where he received his Ph.D. in Zoology in 2001. Dr. Nielsen has devoted much of his 25-year research career to wildlife conservation, having conducted research on dozens of primarily mammalian wildlife species in North America, Central America, South America, and Asia.  He has secured >$12 million in funding from myriad sources to support his research program.  Dr. Nielsen has advised >65 graduate students, post-doctoral fellows, and international scholars; and has employed >200 additional technicians to work on his research projects.  He has published >230 scholarly works (including 160 publications in peer-reviewed journals) and given >650 invited lectures and presentations at professional meetings.  Dr. Nielsen's commitment to research and student training was recognized when he was presented the 2014 Outstanding Scholar Award in the College of Agricultural Sciences at SIU.  Beyond SIU, Dr. Nielsen is active with The Wildlife Society as the Past President of both the North Central Section and Illinois State Chapter and is a Certified Wildlife Biologist®.  He also serves as the Director of Scientific Research for the non-profit Cougar Network and is a member of 3 IUCN Species Survival Commission Specialist Groups (Cats, Lagomorphs, and Deer).  Dr. Nielsen’s research has been showcased by hundreds of major media outlets including TIME magazine, the BBC, National Geographic magazine, NPR, the History Channel, and the Discovery Channel.


Student holding armadillo In conjunction with the Cooperative Wildlife Research Laboratory at SIU, my research group broadly studies ecology, management, and conservation of wildlife with a strong focus on habitat, populations, and human-wildlife conflict.

Recent graduate student research includes ecological studies of (1) armadillos, (2) carnivores (striped skunks, clouded leopards, cougars, jaguars), (3) semi-aquatic furbearers (river otters, mink, beavers, muskrats), and (4) herbivores (deer, sloths, swamp rabbits, eastern woodrats).


  • FOR 405 - Forest Management for Wildlife
  • FOR 451 - Wildlife Habitat and Populations

Descriptions available for each of these classes in course listings for Forestry [FOR].


  • Ph.D., Zoology, Southern Illinois University Carbondale, 2001
  • M.S., Environmental and Forest Biology, SUNY-ESF, 1996
  • B.S., Natural Resources, University of Nebraska, 1994


  • Greenspan, E., A. Giordano, C. Nielsen, K. Jai-Chyi Pei, and N. Ching-Min Sun.  2020. Taiwanese attitudes toward the clouded leopard (Neofelis nebulosa) and its potential reintroduction. Human Dimensions of Wildlife 25:301-323.
  • Rutter, A. U., A. T. Hanrahan, C. K. Nielsen, and E. M. Schauber. 2020. Functionality of a new live-capture device for river otters. Journal of Fish and Wildlife Management 11:238-244.
  • Zieman, E. A., T. Lawson, C. K. Nielsen, and F. A. Jiménez. 2020. Within-season changes in Cytauxzoon felis parasitemia in bobcats. Journal of Parasitology 106:308-311.
  • Cassel, K. W., D. J. Morin, C. K. Nielsen, T. S. Preuss, and G. A. Glowacki. 2020. Low-intensity monitoring of small mammal habitat associations and species interactions in an urban forest preserve network. Wildlife Research 47:114-127.
  • Morin, D., C. Yackulik, J. Diffendorfer, D. Lesmeister, C. K. Nielsen, J. Reid, and E. M. Schauber. 2020. Is your multi-stage model selection strategy affecting your inferences? Ecosphere 11(1), doi: 10.1002/ecs2.2997.
  • Holland, A. M., E. M. Schauber, C. K. Nielsen, and E. C. Hellgren. 2019. River otter and mink occupancy dynamics in riparian systems. Journal of Wildlife Management 83:1552-1564.
  • Hanrahan, A. T., A. U. Rutter, C. K. Nielsen, and E. M. Schauber. 2019. Spatial ecology of river otters in a human-modified landscape. Journal of Mammalogy 100:1327-1339.
  • Swan, J. L., A. Carver, N. Correa, and C. K. Nielsen. 2019. Wildlife rescue and relocation efforts associated with the Panamá Canal Third Locks Expansion Project. Tropical Zoology 32(2):58-74.
  • Shew, J., C. Nielsen, and D. Sparling. 2019. Finer-scale habitat predicts nest survival in grassland birds more than management and landscape: a multi-scale perspective. Journal of Applied Ecology 56:929-945.
  • Marler, H., D. Adams, Y. Wu, C. Nielsen, S. Li, E. Reiner, and D. Chen. 2018. Maternal transfer of flame retardants in sharks from the western North Atlantic Ocean. Environmental Science & Technology 52:12978-12986.
  • Holland, A. M., E. M. Schauber, C. K. Nielsen, and E. C. Hellgren. 2018. Stream community richness predicts apex predator occupancy dynamics in riparian systems. Oikos 127:1422-1436.