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Nathaniel Rayl
Nathaniel Rayl

​​​​Wildlife Researcher, Ungulates/Carnivores


  • 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

Areas of Interest, Expertise

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

Current or Recent Research Projects

​Evaluating factors affecting elk recruitment in Colorado.


  • Rayl, N.D., G. Bastille-Rousseau, J.F. Organ, M.A. Mumma, C.E. Soulliere, R.D. Otto, K.P. Lewis, S.P. Mahoney, and T.K. Fuller. Spatiotemporal heterogeneity in prey abundance and vulnerability shapes the foraging tactics of an omnivore. Journal of Animal Ecology, early view. DOI: 10.1111/1365-2656.12810.

  • 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.

  • 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]

  • 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.​