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Rayl, Nathaniel

(PhD., W&FCON)


Habitat selection, diet, and movements of black bears in Newfoundland: implications for caribou conservation




Institute for Biodiversity, Ecosystem Science & Sustainability (Newfoundland)

Safari Club International Foundation

Faculty Advisor:

Todd Fuller and John Organ

Project Abstract:

After several decades of rapid growth, the semi-migratory caribou herds on the island of Newfoundland, Canada have declined dramatically, decreasing from over 91,000 to less than 33,000 individuals in the last 20 years, likely as a result of density-dependent effects.  With predation accounting for 65-89% of all caribou calf mortalities and annual rates of neonate survival estimated to be < 10%, predation during the first weeks after parturition, principally by black bears and coyotes, is currently considered the proximate limiting factor for the diminished population.  Using GPS telemetry data and stable isotope analyses, I will investigate the distribution, habitat selection, movements, and trophic position of black bears in 3 study areas of Newfoundland to better understand how these factors influence calf survival, why predation rates vary by area, and whether specific individuals are responsible for disproportionate mortality of caribou calves.

Refereed Journal Articles

Bastille-Rousseau, G., J.R. Potts, M.A. Lewis, E.H. Ellington, N.D. Rayl, S.P. Mahoney, J.A. Schaefer, 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. Supplementary Material.

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] Supplemental Material.

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. 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.

Other Publications

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.



Page updated: October 5, 2015