Murray M. Humphries Research People Research Equipment Pictures Collaborators & Funding


Research Interests & Approaches

In general, our research explores how environment, physiology, and behaviour influence the abundance, distribution, and coexistence of mammal populations. Our research is conducted both in the lab and in the field, often in collaboration with northern communities or one of our many partners (Click here to visit our Collaborators & Funding Section).

One of our research focuses is on energetics (the process by which animals acquire and assimilate energy from the environment, and allocate assimilated energy between maintenance, growth, and reproduction). We firmly believe that understanding the ecological implications of energetics ultimately requires field studies that integrate measures of energy intake and expenditure, under conditions of known resource availability, and in situations where behaviour, survival and reproductive success can be documented. Another of our research focuses is on understanding, predicting and monitoring environmental change impacts on northern wildlife and traditional food security in Canada.

Research Projects
(Click on project titles for details)

    Wildlife Energetics


    Environmental Change, Wildlife & Traditional Food Security




    Wildlife Energetics

    Kluane Red Squirrel Project



    We are interested in the many energetic linkages between red squirrels' environment, metabolism, reproduction, and behaviour. We maintain an active, long-term collaboration with Stan Boutin (Alberta), Andrew McAdam (Guelph), John Speakman (Aberdeen) and colleagues in investigating the ecology of a free-ranging population of red squirrels in Kluane, Yukon (Kluane Red Squirrel Project). Red squirrels are interesting because they are small, live in cold places, and rely on a boom and bust food supply, but yet do not hibernate. Kluane red squirrels provide a unique opportunity to identify the energetic solutions to these environmental challenges within a well-quantified resource, life history, and fitness context.

    Representative Publications

    • Boutin, S., A.G. McAdam , M.M. Humphries. 2013. Anticipatory reproduction in squirrels can succeed in the absence of extra food. New Zealand Journal of Zoology 40: 337-339

    • Fletcher, Q.E., M. Landry-Cuerrier, S. Boutin, A.G. McAdam, J.R. Speakman, M.M. Humphries. 2013. Reproductive timing and reliance on hoarded capital resources by lactating red squirrels. Oecologia 173: 1203-1215

    • LaMontagne, J.M., C. T. Williams, J.L. Donald, M.M. Humphries, A.G. McAdam, S. Boutin. 2013. Linking intraspecific variation in territory size, cone supply, and survival of North American red squirrels. Journal of Mammalogy 94:1048-1058

    • Archibald, D.W., Q.E. Fletcher, S. Boutin, A.G. McAdam, J.R. Speakman, M.M. Humphries. 2013. Sex-specific hoarding behavior in North American Red Squirrels (Tamiasciurus hudsonicus). Journal of Mammalogy 94:761-770

    • Fletcher, Q.E., J.R. Speakman, S. Boutin, A.G. McAdam, S.B. Woods, M.M. Humphries. 2012. Seasonal stage differences overwhelm environmental and individual factors as determinants of energy expenditure in free-ranging red squirrels. Functional Ecology 26:677-687.

    • Archibald, D.W., A.G. McAdam, S. Boutin, Q.E. Fletcher, M.M. Humphries. 2012. Within-season synchrony of a masting conifer enhances seed escape. American Naturalist 179: 536-544

    • Gorrell, J.C., A.G. McAdam, D.W. Coltman, M.M. Humphries, S. Boutin. 2010. Adopting kin enhances inclusive fitness in asocial red squirrels. Nature Communications. 1:22 doi: 10.1038/ ncomms1022.

    • Fletcher, Q.E., S. Boutin, J.E. Lane, J.M. Lamontagne, A.G. McAdam, C.J. Krebs, M.M. Humphries. 2010.The functional response of a hoarding seed predator to mast seeding. Ecology, 91:2673-2683.

    • Larivee, M.L., S. Boutin, J.R. Speakman, M.M. Humphries. 2010. Associations between overwinter survival and resting metabolic rate in juvenile North American red squirrels (Tamiasciurus hudsonicus). Functional Ecology, 24:597:607.

    • Lane, J., S. Boutin, J.R. Speakman, M.M. Humphries. 2009.Energetic costs of male reproduction in a scramble competition mating system. Journal of Animal Ecology, 79:27-34.

    • Guillemette, C.U., Q.E. Fletcher, S. Boutin, R.M. Hodges, A.G. McAdam, M.M. Humphries. 2009. Lactating red squirrels experiencing high heat load occupy less insulated nests. Biology Letters, 5:166-168.

    • Kerr, T., S. Descamps. 2008. Why do North American Red Squirrels, Tamiasciurus hudsonicus, relocate their young? A predation-based hypothesis. Canadian Field Naturalist, 122: 65-66.

    • Kerr, T.D., S. Boutin, J.M. Lamontagne, A.G. McAdam, M.M. Humphries. 2007. Persistent maternal effects on juvenile survival in North American red squirrels. Biology Letters, 3:289-291.

    • McAdam, A.G., S. Boutin, A. Sykes, M.M. Humphries. 2007. Life histories of female red squirrels and their contribution to population growth. Ecoscience, 14:362-369.

    • Humphries. M.M., S. Boutin, D.W. Thomas, J.D. Ryan, C. Selman, A.G. McAdam, D. Berteaux, J.R. Speakman. 2005. Expenditure freeze: the metabolic response of small mammals to cold environments. Ecology Letters, 8:1326-1333.

    • Humphries, M.M., S. Boutin. 2000. The determinants of optimal offspring number in free-ranging red squirrels. Ecology, 81:2867-2877.

    Current Graduate Student
    Emily Studd (PhD)


    Former Graduate Students
    Emily Studd (MSc), Devan Archibald (MSc), Quinn Fletcher (PhD), Elad Ben-Ezra (MSc), Sarah Woods (MSc) and Tricia Kerr (MSc)

    Former Co-Supervised Graduate Student
    Meghan Larivee (MSc; S Boutin, Alberta)

    Nature Conservancy Chipmunk Project



    We are interested in the energetics of resource anticipation, acquisition and amplification in eastern chipmunks. We work with Denis Réale (UQAM), Fanie Pelletier (Sherbrooke), and Dany Garant (Sherbrooke) to study, in the eastern townships of Quebec (Nature Conservancy), the behavioural, physiological, and genetic responses of a free-ranging population of eastern chipmunks to natural and artificial resource variation. Chipmunks are particularly interesting from an energetic viewpoint because, as a food-hoarding hibernator, they have incredible energetic flexibility that they use to deal with extreme natural variability in resource abundance. This collaboration provides a unique opportunity to assess correlations between metabolic and behavioural traits, and how these traits independently and collectively influence free-ranging populations.

    Representative Publications

    • Bergeron, P, P.-O. Montiglio, D. Reale, M.M. Humphries, O. Gimenez, D. Garant. 2013. Disruptive viability selection on adult exploratory behavior in eastern chipmunks. Journal of Evolutionary Biology 26:766-774

    • Careau, V., D. Réale, D. Garant, F. Pelletier, J.R. Speakman, M.M. Humphries. 2013. Context-dependent correlation between resting metabolic rate and daily energy expenditure in wild chipmunks. Journal of Experimental Biology 216:418-426

    • Careau, V., P. Bergeron, D. Garant, D. Réale, J. Speakman, M.M. Humphries. 2013. The energetic and survival costs of growth in free-ranging chipmunks. Oecologia 171:11-23

    • Careau, V., D. Garant, & M.M. Humphries. 2012. Free-ranging eastern chipmunks infected with bot fly larvae have higher resting but lower maximum metabolism. Canadian Journal of Zoology 90:413-421

    • Réale, D., D. Garant, M.M. Humphries, P. Bergeron, V. Careau, P.O. Montiglio, D.W. Thomas. 2010. Personality and the emergence of a pace-of-life syndrome at the level of the population. Phil. Trans. R. Soc. B. 365:4051-4063.

    • Careau, V., D.W. Thomas, M.M. Humphries. 2010. Energetic cost of bot fly parasitism in free-ranging eastern chipmunks. Oecologia, 162:303-312.

    • Landry-Cuerrier, M., D. Munro, D.W. Thomas, M.M. Humphries. 2008. Climate and resource determinants of the fundamental and realized metabolic niches of hibernating chipmunks. Ecology, 89:3306-3316.

    • Munro, D., D.W. Thomas, M.M. Humphries. 2008. Extreme suppression of above-ground activity by a food-storing hibernator, the eastern chipmunk (Tamias striatus). Canadian Journal of Zoology , 86:364-370.

    • Hall, C.L., M.M. Humphries, D.L. Kramer. 2007. Resource tracking by eastern chipmunks: the sampling of renewing patches. Canadian Journal of Zoology , 85:536-548.

    • Munro, D, D.W. Thomas, M.M. Humphries. 2005. Torpor patterns of hibernating eastern chipmunks (Tamias striatus) vary in response to the size and fatty acid composition of food hoards. Journal of Animal Ecology, 74:692-700.

    • Humphries, M.M., D.W. Thomas, C.L. Hall, J.R. Speakman, D.L. Kramer. 2002. The energetics of autumn mast hoarding in eastern chipmunks. Oecologia, 133:30-37.

    Former Graduate Student
    Manuelle Landry-Cuerrier (MSc)


    Former Co-Supervised Graduate Student
    Vincent Careau (PhD; D Thomas, Sherbrooke)


    Captive Wildlife Facility

    Outside view Outside view

    This facility, allowing us to combine field and captive approaches in our research on energetics and ecophysiology, is located on Macdonald campus. It is equipped with 30 individual cages consisting of one compartment held within a controlled environmental chamber and connected to another compartment at natural outside temperatures and photoperiod. In the same facility, there is a flow-through respirometry system available to measure metabolic rate of captive animals. It has been operational 3 years, with a design that tries to encourage natural behaviours and examine physiological and behavioural consequences of torpor expression in eastern chipmunks during the hibernation period


    Representative Publications

    • Thompson, A.B., P.-O. Montiglio, M.M. Humphries. 2013. Behavioural impacts of torpor expression: a transient effect in captive eastern chipmunks (Tamias striatus). Physiology & Behavior 110:115-121

    Former Graduate Students
    Marianne Gagnon (MSc), Amy Thompson (MSc)


    Environmental Change, Wildlife & Traditional Food Security



    In collaboration with northern partners and indigenous communities, we are interested in understanding, predicting and monitoring impacts of environmental change on traditionally harvested wildlife species. Working with Laurie Chan (UNBC), Colin Scott (McGill), Stan Boutin (Alberta), and Dominique Berteaux (UQAR), our approach combines community-based participatory research with studies of climatic and environmental determinants of the distribution and abundance of species.

    Representative Publications

    • Berteaux, D., S. de Blois, J.-F. Angers, N. Casajus, M. Darveau, F. Fournier, M.M. Humphries, B. McGill, J. Larivée, T. Logan, P. Nantel, C. Périé, F. Poisson, D. Rodrigue, S. Rouleau, R. Siron, W. Thuiller, L. Vescovi. 2010. From global change to regional conservation: effects of climate change on Quebec biodiversity. Diversity. 2: 1181-1204.

    • Berteaux, D., M.M. Humphries, C.J. Krebs, M. Lima, A.G. McAdam, N. Pettorelli, D. Réale, T. Saitoh, E. Tkadlec, R.B. Weladji, N.C. Stenseth. 2006. Constraints to predicting the effects of climate change on mammals. Climate Research, 32:151-158.

    • Humphries, M.M., J. Umbanhowar, & K.S. McCann. 2004. Bioenergetic prediction of climate change impacts on northern mammals. Integrative and Comparative Biology, 44:152-162.

    • Humphries, M.M., D.W. Thomas, & J.R. Speakman. 2002. Climate-mediated energetic constraints on the distribution of hibernating mammals. Nature, 418:313-316.

    Former Co-Supervised Graduate Students
    April Kinghorn (MSc; L Chan, McGill) , Sonja Ostertag (MSc; L Chan, McGill) and Thomas Doniol-Valcroze (PhD; D Berteaux, UQAR)

    Former Graduate Student
    Troy Pretzlaw (MSc)

    Eastern James Bay Wildlife



    We work with the Cree Nation of Wemindji and the Wemindji Cree Trappers Association, as part of the Paakumshumwaau-Wemindji Protected Area Project, to better understand environmental determinants of local traditonal food and furbearing species abundance, with a particular focus on furthe beaver. With the collaboration of Wemindji Cree trappers and community members, who have provided beaver tissue samples and guided us in the field, we are investigating beaver's diet and population structure using DNA and isotope analyses, and also estimating local wildlife abundance using simple winter snowtracking surveys. More recently, we have been involved with the Cree Nation of Chisasibi to better understand the relationships between coastal vegetation, geese abundance, and Cree harvest and culture.

    Representative Publications

    • Milligan, H.E., M.M. Humphries. 2010. The importance of aquatic vegetation in beaver diets and the seasonal and habitat specificity of aquatic-terrestrial ecosystem linkages in a subarctic environment. Oikos. 119: 1877–1886.

    • Jarema, S.I., J. Samson, B.J. McGill, M.M. Humphries. 2009. Variation in abundance across a species’ range predicts climate change responses in the range interior will exceed those at the edge: a case study with North American beaver. Global Change Biology, 15:508-522.

    Current Graduate Student
    Mélanie-Louise Leblanc (PhD)

    Former Graduate Students
    Jason Samson (PhD), Heather Milligan (MSc) and Stacey Jarema (MSc)


    Old Crow Moose and Muskrat Project



    As part of the YNNK IPY project on environmental change and traditional use of the Old Crow Flats (OCF), near Old Crow, Yukon, we work with a mutlidisciplinary research team to study the distribution and abundance of wildlife in relation with environmental change and traditional food security. In close collaboration with Yukon Environment, North Yukon Renewable Resource Council, VGFN Government and with the Old Crow community, we are involved in monitoring moose movements in and out of OCF using telemetry, estimating muskrat abundance by doing aerial surveys and in developing a community-based muskrat carcass collection program to monitor muskrat condition and genetic relatedness.

    Current Graduate Students
    Jeremy Brammer (PhD) and Xavier Giroux-Bougard (MSc)

    Pond Inlet Narwhal Project



    As part of The Narwhal Expedition, we collaborate with the Mittimatalik Hunters and Trappers Organization, with Marie Auger-Méthé and Hal Whitehead at Dalhousie University, and with Polar Sea Adventures, to study and monitor narwhal populations in northern Canada. We use visual observation, photo-identification and acoustic recording to investigate narwhal movements and social behaviour in relation with environmental change and increased shipping traffic.

    Related Publication
    • Marcoux, M., M. Auger-Méthé, M.M. Humphries. 2012. Variability and contextspecificity of narwhal (Monodon monoceros) whistles and pulsed calls. Marine Mammal Science 28:649-665

    • Marcoux, M., Auger-Méthé M, Chmelnitsky E, Ferguson SH, Humphries MM. 2011. Local passive acoustic monitoring of narwhal presence in the Canadian Actic: a pilot project. Arctic 64:307-316.

    • Marcoux, M., G. Larocque, M. Auger-Méthé, P. Dutilleul, M.M. Humphries (2010) Statistical analysis of animal observations and marks distributed in time using Ripley functions. Animal Behaviour, 80: 329-337.

    • Marcoux M, Auger-Méthé M and Humphries M. (2009) Encounter frequencies and grouping patterns of narwhals in Koluktoo Bay, Baffin Island. Polar Biology, 32:1705-16.

    Former Graduate Student
    Marianne Marcoux (PhD)



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Created: November 2005
Last Updated: January 2014