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Nathaniel Rayl
Nathaniel Rayl

​​​​Wildlife Researcher, Ungulates/Carnivores

Current or Recent Research Projects

  • ​Evaluating factors affecting elk recruitment in Colorado
  • Assessing responses of elk to human recreation in Colorado

Areas of Interest and Expertise

My research focuses on large mammal ecology and management, with an emphasis on spatial ecology, population dynamics, and predator-prey interactions.

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Emblems of the West

Select Publications

  • Bastille-Rousseau, G., S. A. Crews, E. B. Donovan, M. E. Egan, N. T. Gorman, J. B. Pitman, A. M. Weber, E. M. Audia, M. R. Larreur, H. Manninen, S. Blake, M. W. Eihholz, E. Bergman, and N. D. Rayl. 2024. A multi‐property assessment of intensity of use provides a functional understanding of animal movement. Methods in Ecology and Evolution 15:345-357.​
  • Rayl, N.D., J.A. Merkle, K.M. Proffitt, E.S. Almberg, J.D. Jones, J.A. Gude, and P.C. Cross. 2021. Elk migration influences the risk of disease spillover in the Greater Yellowstone Ecosystem. Journal of Animal Ecology 90:1264-1275.
  • Rayl, N.D., K.M. Proffitt, E.S. Almberg, J.D. Jones, J.A. Merkle, J.A. Gude, and P.C. Cross. 2019. Modeling elk-to-livestock transmission risk to identify hotspots of brucellosis spillover. Journal of Wildlife Management 83:817-829.
  • Rayl, N.D., K.M. Proffitt, E.S. Almberg, J.D. Jones, J.A. Merkle, and P.C. Cross. 2018. Estimating the risk of elk-to-livestock brucellosis transmission in Montana. Montana Fish, Wildlife and Parks, Helena, MT, USA.
  • Rayl, N.D., G. Bastille-Rousseau, J.F. Organ, M.A. Mumma, S.P. Mahoney, C.E. Soulliere, K.P. Lewis, R.D. Otto, D.L. Murray, L.P. Waits, and T.K. Fuller. 2018. Spatiotemporal heterogeneity in prey abundance and vulnerability shapes the foraging tactics of an omnivore. Journal of Animal Ecology 87:874-887.
  • Morjan, M.D.*, N.D. Rayl*, P.W. Elkan, J.C. Deutsch, M.B. Henke, and T.K. Fuller. 2018. Armed conflict and development threatens some of Africa’s longest and largest ungulate migrations. Biodiversity and Conservation 27:365-380. [*shared first authorship] 
  • Bastille-Rousseau, G., J.A. Schaefer, M.J.L. Peers, E.H. Ellington, M.A. Mumma, N.D. Rayl, S.P. Mahoney, and D.L. Murray. 2018. Climate change can alter predator-prey dynamics and population viability of prey. Oecologia 186:141-150.
  • Mumma, M.A., J.D. Holbrook, N.D. Rayl, C.J. Zieminski, T.K. Fuller, J.F. Organ, S.P. Mahoney, and L.P. Waits. 2017. Examining spatial patterns of selection and use for an altered predator guild. Oecologia 185:725-735. 
  • Bastille-Rousseau, G., J.A. Schaefer, K.P. Lewis, M.A. Mumma, E.H. Ellington, N.D. Rayl, S.P. Mahoney, D. Pouliot, and D.L. Murray. 2016. Phase-dependent climate-predator interactions explain three decades of variation in neonatal caribou survival. Journal of Animal Ecology 85:445-456.
  • Bastille-Rousseau, G., N.D. Rayl, E.H. Ellington, J.A. Schaefer, M.J.L. Peers, M.A. Mumma, S.P. Mahoney, and D.L. Murray. 2016. Temporal variation in habitat use, co-occurrence, and risk among generalist predators and a shared prey. Canadian Journal of Zoology 94:191-198.
  • Bastille-Rousseau, G., J.R. Potts, J.A. Schaefer, M.A. Lewis, E.H. Ellington, N.D. Rayl, S.P. Mahoney, and D.L. Murray. 2015. Unveiling trade-offs in resource selection of migratory caribou using a mechanistic movement model of availability. Ecography 38:1049-1059.
  • Rayl, N.D., T.K. Fuller, J.F. Organ, J.E. McDonald, Jr., R.D. Otto, G. Bastille-Rousseau, C.E. Soulliere, and S.P. Mahoney. 2015. Spatiotemporal variation in the distribution of potential predators of a resource pulse: black bears and caribou calves in Newfoundland. Journal of Wildlife Management 79:1041-1050. [Cover article]
  • Rayl, N.D., T.K. Fuller, J.F. Organ, J.E. McDonald, Jr., R.D. Otto, and S.P. Mahoney. 2014. Den abandonment and transitional day bed use by black bears Ursus americanus in Newfoundland. Wildlife Biology 20:222-228.
  • Rayl, N.D., T.K. Fuller, J.F. Organ, J.E. McDonald, Jr., S.P. Mahoney, C. Soulliere, S.E. Gullage, T. Hodder, F. Norman, T. Porter, G. Bastille-Rousseau, J.A. Schaefer, and D.L. Murray. 2014. Mapping the distribution of a prey resource: neonate caribou in Newfoundland. Journal of Mammalogy 95:328-339.
  • Sitompul, A.F., C.R. Griffin, N.D. Rayl, and T.K. Fuller. 2013. Spatial and temporal habitat use of an Asian elephant in Sumatra. Animals 3:670-679.
  • Fuller, T.K., S.M. Matthews, S.S. Stevens, N.D. Rayl, C.J. Zieminski, A.R. Whiteley, P.R. Sievert, J.F. Organ, and M.W. Gabriel. 2010. Book review: Noninvasive survey methods for carnivores. Journal of Wildlife Diseases 46:1055-1058.​


  • Ph.D., Wildlife, Fish & Conservation Biology – University of Massachusetts, 2017
  • M.S., Wildlife, Fish & Conservation Biology – University of Massachusetts, 2012
  • B.A., Philosophy – Haverford College, 2000

Current or Recent Positions

  • Wildlife Researcher – Colorado Parks and Wildlife, 2018-Present
  • Ecologist – U.S. Geological Survey, 2016-2018