Mark Ditmer, PhD

Research Ecologist

Rocky Mountain Research Station

0000-0003-4311-3331

mark.ditmer@usda.gov

Publications & Products
Related
Education

Treesearch Publications

Annabelle Moore, Mark Ditmer. 2026. Trails and tails: Using smart-phone GPS data to balance recreation and wildlife management
Mark Ditmer, Katherine Zeller, Heather N. Abernathy, James Wilder, Ashley Egan, Julia N.D. Daniell, Jesse R. Barber, William L. Rice, Michael K. Schwartz, George Wittemyer. 2026. The landscape of no worries? Increased recreation exposure decreases the landscape of human fear in wildlife
Madeline P. Standen, Mark Ditmer, David C. Stoner, Kent R. Hersey, Neil H. Carter. 2025. Differential effects of environmental predictability on ungulate movement behavior in disparate ecosystems
Kirby L. Mills, Martin Leclerc, Mark Ditmer, Zachary Steel, David C. Stoner, Joseph O. Sexton, Panshi Wang, Kent R. Hersey, Darren DeBloois, Cody A. Schroeder, Kathryn A. Schoenecker, Julie K. Young, Alyson M. Andreasen, Kathleen M. Longshore, Patrick J. Jackson, Derek B. Hall, Kristin Engebretsen, Neil H. Carter. 2025. Long‐term benefits of burns for large mammal habitat undermined by large, severe fires in the American West
Martin Leclerc, Mark Ditmer, David C. Stoner, Panshi Wang, Joseph O. Sexton, Kent R. Hersey, Neil H. Carter. 2025. Acute drought desiccates highly used habitat and drives herbivores into irrigated croplands
Maksim Sergeyev, Mark Ditmer, Kira Z. Deming, Natasha Goedert, Michael K. Schwartz, Sam Massman, George Wittemyer. 2025. Leveraging human mobility data to assess recreational activity across the United States’ most visited National Forest
Heather Abernathy, Mark Ditmer, Seth B. Hibbard, Jason V Lombardi, Thomas R. Stephenson, John R. Squires, Jennifer N. Newton, Sarah R. Dewey, Katherine Zeller, Michael K. Schwartz, George Wittemyer. 2025. A case for human mobility data applications in wildlife management
Heather Abernathy, Mark Ditmer, David C. Stoner, Kent R. Hersey, Kathryn A. Schoenecker, Pat J. Jackson, Kristin Engebretsen, Julie K. Young, George Wittemyer. 2025. Dynamic riskscapes for prey: disentangling the impact of human and cougar presence on deer behavior using GPS smartphone locations
Sylvia Kantor, Katherine Zeller, Mark Ditmer, John R. Squires, Jesse Barber, James Wilder, Ashley Egan. 2025. How human-generated noise disrupts wildlife: The unseen impact of outdoor recreation
Katherine Zeller, Mark Ditmer, John R. Squires, William L. Rice, James Wilder, Don DeLong, Ashley Egan, Niah Pennington, Chris A. Wang, Jacinta Plucinski, Jesse R. Barber. 2024. Experimental recreationist noise alters behavior and space use of wildlife
Mark Ditmer, Neil H. Carter, Kent R. Hersey, Martin Leclerc, George Wittemyer, David C. Stoner. 2023. Navigating the wildland-urban interface: Sensory pollution and infrastructure effects on mule deer behavior and connectivity
Kaitlyn M. Frank, Mark Ditmer, David C. Stoner, William S. Currie, Daniel D. Olson, Neil H. Carter. 2023. Dark roads aid movement but increase mortality of a generalist herbivore in the American Southwest
Mark Ditmer, George Wittemyer, Katherine Zeller, Stewart W. Breck, Robert J. Fletcher, Kevin R. Crook. 2023. Predicting dispersal and conflict risk for wolf recolonization in Colorado
Mark Ditmer, Rebecca M. Niemiec, George Wittemyer, Kevin R. Crooks. 2022. Socio-ecological drivers of public conservation voting: Restoring gray wolves to Colorado, USA
Mark Ditmer, George Wittemyer, Stewart W. Breck, Kevin R. Crooks. 2022. Defining ecological and socially suitable habitat for the reintroduction of an apex predator
Mark Ditmer, Clinton D. Francis, Jesse R. Barber, David C. Stoner, Brett M. Seymoure, Kurt M. Fristrup, Neil H. Carter. 2021. Assessing the vulnerabilities of vertebrate species to light and noise pollution: Expert surveys illuminate the impacts on specialist species
Mei-Hsiu Hwang, Mark Ditmer, Shu-De Teo, Siew Te Wong, David L. Garshelis. 2021. Sun bears use 14-year-old previously logged forest more than primary forest in Sabah, Malaysia
Nicholas P. McCann, Eric M. Walberg, James D. Forester, Michael W. Schrage, David C. Fulton, Mark Ditmer. 2021. Integrating socioecological suitability with human-wildlife conflict risk: Case study for translocation of a large ungulate

Citations of Non-Forest Service Publications

Stoner, D.C., M.A. Ditmer, D.L. Mitchell, J.K. Young, and M.L. Wolfe. 2021. Conflict, coexistence, or both? Cougar habitat selection, prey composition, and mortality in a multiple-use landscape. California Fish and Wildlife Journal 107(3):147-172.Ditmer, M.A., D. Stoner,…, J.R. Barber, and N.H. Carter. 2021. Artificial nightlight alters the predator–prey dynamics of an apex carnivore. Ecography. 43:1–13. McMahon, M, M.A. Ditmer, and J.D. Forester. 2021 Comparing unmanned aerial systems to conventional methodology for surveying a wild white-tailed deer population. Wildlife Research. Ditmer, M.A., C.D. Francis,…, J.R. Barber, and N.H. Carter. 2021. Assessing the vulnerabilities of vertebrate species to light and noise pollution: expert surveys illuminate the impacts on specialist species. Integrative & Comparative Biology 61 (3):1202-1215. Wilson, A.A. M.A. Ditmer, J.R. Barber3, N.H. Carter, E.T. Miller, L.P. Tyrrell, S. Drabing, C.D. Francis. 2021. Light and noise pollution interact to influence bird abundance across a continental scale. Global Change Biology. McMahon, M, M.A. Ditmer, E.J. Isaac, S.A. Moore, and J.D. Forester. 2021. Evaluating unmanned aerial systems for the detection and monitoring of moose in northeastern Minnesota. Wildlife Society Bulletin. Ditmer, M.A., D. Stoner, and N.H. Carter. 2021. Estimating the loss and fragmentation of dark environments in mammal ranges from light pollution. Biological Conservation 257, 109135. Ditmer, M.A., F. Iannarilli, A.N. Tri, D.L. Garshelis, and N.H. Carter. 2021. Artificial night light helps account for observer bias in citizen science monitoring of an expanding large mammal population. Journal of Animal Ecology – Special Feature on Citizen Science. Garshelis, D.L., K.V. Noyce, M.A. Ditmer, T.G. Laske, and P.A. Iaizzo. 2020. Remarkable adaptations of the American black bear help explain why it is the most common bear: Long-term study from the centre of its range. In Bears of the World: Ecology, Conservation and Management. V. Penteriani & M. Melletti (Editors). Cambridge University Press. Cambridge, U.K. Senzaki, M., J.R. Barber, J.N. Phillips, N.H. Carter, C.B. Cooper, M.A. Ditmer, K.M. Fristrup…and C.D. Francis. 2020. Sensory pollutants alter bird phenology and fitness across a continent. Nature. 587 (7835), 605-609. Ditmer, M.A., A.M. McGraw, … V. St-Louis, K. VanderWaal, and M. Carstensen. 2020. Using movement ecology to investigate meningeal worm risk in moose. Journal of Mammalogy gyaa019. Muntifering, J., M.A. Ditmer, R. Naidoo, S. Stapleton, and T. Harris. 2019. Characterizing Hartmann’s mountain zebra resource selection and movement behavior within a large unprotected landscape in north-west Namibia. Endangered Species Research 38:159-170. Prugh, L.R., K.J. Sivy, P. Mahoney, T. Ganz, M.A. Ditmer, M. van de Kerk, S. Gilbert, and B. Montgomery. 2019. Designing predation risk studies for improved inference. Special issue: Multi-Species Risk Effects in Carnivore-Ungulate Systems. Biological Conservation 232, 194–207. Ditmer, M.A., L.K. Werden, J.C. Tanner, J.B. Vincent, P. Callahan, P.A. Iaizzo, T.G. Laske, D.L. Garshelis. 2019. Bears habituate to the repeated exposure of a novel stimulus, unmanned aerial vehicles. Conservation Physiology 6:1 coy067.
Ditmer, M.A., D.L. Garshelis, K.V. Noyce, and J.R. Fieberg. 2018. Delineating the ecological and geographic edge of an opportunist: The American black bear exploiting an agricultural landscape. Ecological Modelling 387C: 205-219.Laske, T.G., A.L. Evans, J.M. Arnemo, T.L. Iles, M.A. Ditmer, O. Frobert, D.L. Garshelis, and P.A. Iaizzo. 2018. Development and utilization of implantable cardiac monitors in free-ranging American black and Eurasian brown bears - system evolution and lessons learned. Animal Biotelemetry 6:13.Ditmer, M.A., J.R. Fieberg, R.A. Moen, S.K. Windels, S.P. Stapleton, and T.R. Harris. 2018. Moose movement rates are altered by wolf presence in two ecosystems. Ecology and Evolution 8:9012-9033. Ditmer, M.A., S.J. Rettler, J.F. Fieberg, P.A.Iaizzo, T.G.Laske, K.V. Noyce, D.L. Garshelis. 2018. American black bears perceive the risks of crossing roads. Behavioral Ecology 29:667 –675. Ditmer, M.A., S.K. Windels, R.A. Moen, J.D. Forester, T.R. Harris. 2017. Moose at their bioclimatic edge alter their behavior based on weather, landscape, and predators. Current Zoology 64:419-432 Ditmer, M.A., D.L. Garshelis, K.V. Noyce, A. Havales and J.R. Fieberg. 2016. Are American black bears in an agricultural landscape being sustained by crops? Journal of Mammalogy 97: 54-67. Werden, L.K., J.B. Vincent, J.C. Tanner, and M.A. Ditmer. 2015. Not quite free yet: clarifying UAV regulatory progress for ecologists. Frontiers in Ecology and the Environment 3.10: 534-535. Ditmer, M.A., J.B. Vincent, L.K. Werden, J. Tanner, T.G. Laske, P.A. Iaizzo, J.R. Fieberg and D.L. Garshelis. 2015. Bears show a physiological but only a limited behavioral response to unmanned aerial vehicles. Current Biology 25: 2278–2283. Signer, J.N. Balkenhol, M.A. Ditmer and J. Fieberg. 2015. Does estimator choice influence our ability to detect changes in home-range size? Animal Biotelemetry 3:16. Ditmer, M.A., T.E. Burk and D. L. Garshelis. 2015. Do innate food preferences and learning affect crop raiding by American black bears? Ursus 26: 40–52. Ditmer, M.A., D.L. Garshelis. K.V. Noyce, T.G. Laske, P.A. Iaizzo, J. D. Forester, T. E. Burk, and J. R. Fieberg. 2015. Behavioral and physiological responses of American black bears to landscape features within an agricultural region. Ecosphere 6:art28. Vincent, J.B., L.K. Werden, and M.A. Ditmer. 2015. Barriers to adding UAVs to the ecologist's toolbox. Frontiers in Ecology and the Environment 13: 74–75. Ditmer, M.A., Stapleton S. P. 2012. Factors Affecting Hatch Success of Hawksbill Sea Turtles on Long Island, Antigua, West Indies. PLoS ONE 7(7): e38472. Fieberg, J.R., and M.A. Ditmer. 2012. Understanding the causes and consequences of animal movement: A cautionary note on fitting and interpreting regression models with time-dependent covariates. Methods in Ecology and Evolution 6 (3), 983-991