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Ève Rioux


Ph.D. student

Department of biology, chemistry and geography, UQAR

Des Ursulines Building
300 Allée des Ursulines
Quebec, Canada
G5L 3A1

4187231986 extension 1867



Projet de recherche

Individual variability in foraging ecology and physiological condition of the Gaspésie caribou population and trophic relationships between mooses, coyotes and black bears


Foraging and physiological condition are key determinants in ecology as they can affect individual growth, reproduction and survival. Nutrition is link to body condition and may influences juvenile growth rate, adult mass gain, probability of pregnancy, over-winter survival, timing of parturition, neonatal birth mass and survival.

During my thesis project, I will study individual differences in the diet composition and physiological condition of the endangered Atlantic-Gaspésie caribou population using chemical markers. I will evaluate trophic relationships between the caribou, moose, coyote and black bear in the Gaspésie national park using stable isotope analyses.

Study sites

We focused our study on the range of the Atlantic–Gaspésie caribou population, a small and relict herd using bare habitats found at high elevations in the Gaspésie National Park. Three groups of summits are used by caribou, namely the Logan ridge, Albert plateaus, and McGerrigle area. The study area is characterized by three distinct ecological zones, the montane area, the subalpine forest, and the alpine tundra. The population was designated as Endangered in 2000 under the Canadian Species at Risk Act and the estimated population size ranged between 69 and 82 caribou in the 2017 aerial survey.

Material and methods

We collected hair and blood samples from 44 caribou captured in 2013 and 2014 and hair samples from mooses, coyotes and black bears between 2016 and 2018. We collected more than 500 plant samples across the Gaspésie caribou range. Carbon and nitrogen stable isotope signatures will be measured for hair and blood samples. We measured trace element concentrations for caribou hair samples only.

Expected results

This study will provide essential information to understand the ecology of this isolated herd and to contribute efficiently to its recovery. It is the first step to study link between nutrition, body condition, reproduction and survival.

Location of the research site

Scientific communications

Rioux, È., Pelletier, F., St-Laurent, M.-H., 2019. Influence of lipids on stable isotope ratios in mammal hair: highlighting the importance of validation. Ecosphere, 10(5), e02723. DOI: 10.1002/ecs2.2723.

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