Heather Bryan, PhD
Dr. Bryan’s research aims to elucidate the responses of wildlife to environmental change using bioindicators combined with landscape-level analyses and modeling. Specifically, she uses measures of individual health, such as parasites and hormones, to better understand the effects of potential stressors on wildlife.
This approach provides understanding of the mechanisms by which wildlife respond to environmental change, which in turn may inform conservation and management practices aimed at promoting wildlife health. Current areas of research include the role of predators in the ecology of diseases, the effects of landscape change on parasite-host associations, and the relationships between environmental change, physiology, and disease susceptibility in wildlife.
Examining patterns in wildlife health across the landscape
Wildlife have remarkable capacity for responding to environmental change; however many species are facing an increasing number of complex stressors that may compromise their ability to cope. My research aims to elucidate the responses of wildlife to environmental change by examining patterns in wildlife health across the landscape. Specifically, I use measures of individual health (e.g., parasites, hormones, growth) to examine the effects of potential stressors, such as food shortages and competition, on wildlife populations. This approach provides understanding of how and why wildlife respond to environmental change, which in turn can inform policy and conservation interventions aimed at promoting wildlife health.
As one example, my dissertation research revealed that grizzly bears may experience both nutritional and social stress as a result of salmon declines. This finding suggests that conservation efforts should focus not only on food security in this case fisheries management strategies aimed at protecting salmon runs for bears but also on regulating human activities on salmon streams that might alter bear social interactions when feeding on salmon. By applying a similar approach to wolves from northern Canada, colleagues and I found that heavily hunted wolves had higher stress and reproductive hormones compared with lightly hunted wolves. Although the long-term effects of chronically elevated stress and reproductive hormones are unknown, there are potential implications for wildlife health, welfare, long-term survival, and behaviour. Therefore, our findings emphasize that conservation and management plans should consider the possible social and physiological effects of intensely applied control programs on wildlife.
In my current work, I am collaborating with partners from academia and the provincial government to investigate the environmental conditions that influence grizzly bear size and growth across the province of British Columbia. This work may reveal new insight into the responses of bears to changing habitat over time, which in turn might inform land use planning. As part of the Central Coast Bear Working Group’s long-term bear research program, I am working with Indigenous and academic partners to apply new methods of monitoring bear population health using environmental DNA. Results will provide guidance on the most cost-effective strategy for monitoring bears during salmon runs.
Pawluk*, K., Fox, C.H., Stredulinsky, E., Service, C.N., Bryan, H.M. In Revision. Raising the bar: Recovery ambition for species at risk in Canada and the U.S. *All authors contributed equally
Darimont, C.T., Fox, C.H., Bryan, H.M., and Reimchen, T.E. 2015. The unique ecology of human predators. Science 349: 858-860.
Bryan, H.M., Musiani, M., Koren, L., Paquet, P.C., Wynne-Edwards, K. E., and Smits, J.E.G. 2014. Heavily hunted wolves have higher stress and reproductive steroids than wolves with lower hunting pressure. Functional Ecology 29: 347-356. doi: 10.1111/1365-2435.12354
A.V. Stronen, E.L. Navid, M.S. Quinn, P.C. Paquet, H.M. Bryan, and C.T. Darimont. 2014. Population genetic structure of gray wolves (Canis lupus) in a marine archipelago suggests island-mainland differentiation consistent with dietary niche. BMC Ecology 14:11.
Bryan, H.M., Darimont, C.T., Paquet, P.C., Wynne-Edwards, K.E., and Smits, J.E.G. 2014. Stress and reproductive hormones reflect inter-specific social and nutritional conditions mediated by resource availability in a bear-salmon system. Conservation Physiology 2: 10.1093/conphys/cou010
Bryan, H.M., Darimont, C.T., Paquet, P.C., Wynne-Edwards, K. E., and Smits, J.E.G. 2013. Stress and reproductive hormones in grizzly bears reflect the nutritional benefits and social consequences of a salmon foraging niche. PLoS ONE 8: e80537. doi:10.1371/journal.pone.0080537
Bryan, H.M., Adams, A.G., Invik, R.M., Wynne-Edwards, K.E., Smits, J.E. 2013. Hair is a more repeatable reflection of baseline cortisol than saliva or feces in dogs. Journal of the American Association for Laboratory Animal Science 52: 189-196.
Bryan, H.M., Darimont, C.T., Hill, J.E., Paquet, P.C., Thompson, R.C.A., Wagner, B., Smits, J.E.G. 2012. Seasonal and biogeographic patterns of parasites in large carnivores: wolves in a coastal archipelago. Parasitology 139:781-90.
Ellis, J., Anseeuw, E., Gow, S., Bryan, H., Salb, A., Goji, N., Rhodes, C., La Coste, S., Smits, J., Kutz, S. 2011. Population-based seroepidemiology of respiratory (group 2) canine coronavirus and Bordetella bronchiseptica infections in urban dogs in a humane shelter and in rural dogs in small communities. Canadian Veterinary Journal 52:861868.
Bryan, H.M., Darimont, C.T., Paquet, P.C., Ellis, J.A., Goji, N., Gouix, M. and Smits, J.E. 2011. Exposure to infectious agents in dogs in remote coastal British Columbia: possible sentinels of diseases in wildlife and people. Canadian Journal of Veterinary Research 75: 11-17.
Darimont, C.T., Bryan, H.M., Carlson, S.M., Hocking, M.D., MacDuffee, M., Paquet, P.C., Price, M. H.H., Reimchen, T.E., Reynolds, J.D., and Wilmers, C. 2010. Salmon for terrestrial protected areas. Conservation Letters 3: 379-389.
Bryan, H.M., Sim, K.A., Darimont, C.T., Paquet, P.C., Wagner, B.W., Muoz-Fuentes, V., Smits, J.E., and Chilton, N.B. 2010. Identification of Parelaphostrongylus odocoilei (Nematoda: Protostrongylidae) first-stage larvae in the feces of gray wolves (Canis lupis) by molecular methods. Journal of Wildlife Diseases 46: 297-302.
Darimont, C.T., Reimchen, T.E., Bryan, H.M., and Paquet, P.C. 2008. Faecal-centric approaches to wildlife ecology and conservation; methods, data, and ethics. Wildlife Biology in Practice 4: 73-87
Bryan, H.M., Darimont, C.T., Reimchen, T.E., and Paquet, P.C. 2006. Early ontogenetic diet in Gray Wolves (Canis lupus). Canadian Field Naturalist 120: 61-66. (Undergraduate work).
Bryan, H. and Harder, J. Reproduction and Hormones. In: Silvy, N.J. (Ed). The Wildlife Techniques Manual. John Hopkins University Press (Book Chapter in Revision)
Darimont, C.T., Artelle, K., Bryan, H.M., Genovali, C., MacDuffee, M., and Paquet, P.C. 2015. Grizzly bears, salmon, and people; the upstream journey to fisheries sustainability. In: Kemmerer, L.M. (Ed). Bear Necessities. Koninjlike Brill, Leiden, Netherlands.
Bryan, H.M., Gouix, M., and Smits, J.E.G. 2014. Too close for comfort: encounters with Giardia in urban and rural settings. In: Stone, E., and Dewey, C. (Eds.) SICK! Curious Tales of Pests & Parasites We Share with Animals. Ontario Veterinary College, Guelph, Ontario, Canada.