Department of biology, chemistry and geography, UQAR
Des Ursulines Building
300 Allée des Ursulines
418.723.1986 extension 1241
Behavioural flexibility and functional responses of an opportunistic omnivorous predator, black bear, to occasional and heterogeneous food sources along an anthropogenic disturbance gradient.
Omnivorous predators, such as black bear (Ursus americanus), behave to maximize their food intakes. They usually feed on predictable, abundant food sources involving low energy expenditure to gain body mass (e.g., grass and sedges, new growth deciduous leaves, fruits, hard mast and even anthropogenic food, depending on the season) instead of seeking for energy-rich animal preys that are rare and unpredictable. This behaviour seems to support the optimal foraging theory. However, several studies have observed occasional, but sometime important, bear consumption of vulnerable animal preys. Individuals that feed on animal food sources appeared to have better condition and higher reproductive success. Ungulate neonates and yearlings seem to be the most common prey used by black bears. Although animal consumption usually counts for a small part of bear diet, they are often considered as the most important predator of forest-dwelling caribou (Rangifer tarandus caribou) calves and consequently have the greater impact on the demography of this vulnerable species. Our objectives are then to characterise black bear diet and to describe its habitat selection and space use behaviours along an anthropogenic disturbance gradient. Indeed, interaction between heterogeneous food distribution and human-induced disturbances (e.g., clearcuts, roads, perennial infrastructures such as cabins and industrial sites) have never been tested according to black bear ecology in the boreal ecosystem, especially where bears are living in sympatry with caribou. This knowledge, together with information already available on caribou behaviour, will help us proposing new guidelines to reduce black bear impacts on caribou calves. To answer these questions, black bear (12 males, 12 females) inhabiting boreal forest north of Saguenay (Quebec) were fitted with GPS/Argos collars. The study area offers a great structural diversity at all spatial scale, allowing us to study bear responses to a wide range of disturbance intensity. This project will improve our knowledge of bear-caribou interactions and will allow us to update and enlarge our understanding of the ecology of this opportunistic and largely distributed species.
Lesmerises, R., St-Laurent, M.-H., 2017. Not accounting for interindividual variability can mask habitat selection patterns: a case study on black bears. Oecologia, 185(3): 415–425. DOI: 10.1007/s00442-017-3939-8.
Lesmerises, R., Rebouillat, L., Dussault, C., St-Laurent, M.-H., 2015. Linking GPS telemetry surveys and scat analyses helps explain variability in black bear foraging strategies. PLoS one, 10(7): e0129857. DOI: 10.1371/journal.pone.0129857.
Lesmerises, R., Ouellet, J.-P., Dussault, C., St-Laurent, M.-H., 2013. The influence of landscape matrix on isolated patch use by wide-ranging animals: conservation lessons for woodland caribou. Ecology and Evolution, 3(9): 2880–2891. DOI: 10.1002/ece3.695.
Lesmerises, R., Ouellet, J.-P., St-Laurent, M.-H., 2011. Assessing terrestrial lichen biomass using ecoforest maps: a suitable approach to plan conservation areas for forest-dwelling caribou. Canadian Journal of Forest Research, 41: 633-643. DOI: 10.1139/X10-229.