2500, boul. de l'Université
Université de Sherbrooke
819.821.8000 extension 63020
Among species that provide parental care (i.e. any behaviour that is likely to improve offspring fitness in terms of survival and reproduction), there is a trade-off between energy allocation to current and future reproduction. The outcome will depend on the balance between the fitness costs and benefits associated with parental care. However, several environmental constraints can intervene by imposing important selective pressures, therefore altering this balance between costs and benefits.
Hunting can act as a strong selective pressure and can sometimes even operate in contradiction with natural selection. For example, by targeting males with large horns, trophy hunting in the Ram Mountain bighorn sheep (Ovis canadensis) has indirectly favored males with slowly growing horns leading to a significant reduction in overall horn size. In the Scandinavian brown bear (Ursus arctos), where hunting pressure is important, actual Swedish regulation prohibits hunting of family groups, which means that females caring for cubs are legally protected. It is therefore conceivable that current hunting pressure indirectly favors reproductive females that nurse their cubs for longer periods of time because they are unavailable for hunting.
Our main objective is to evaluate hunting pressure on maternal care duration and reproductive strategies in the Scandinavian brown bear. We will also address potential consequences of an increase in maternal care duration on maternal and offspring fitness as well as population dynamics.
To do so, we rely on a long-term (1984-today) monitoring program of the Swedish brown bear population that is carried out by the Scandinavian Brown Bear Research Project (SBBRP). Counts of females and cubs are performed thrice a year (den emergence, reproductive season and den entry) from a helicopter, which allows us to determine the moment of family breakup. The intensive SBBRP monitoring program provides us access to a large sample of marked females that were followed from birth to death as well as a complete pedigree or marked bears in order to establish heritability of traits and their evolutionary potential.
Frank, S.C., Ordiz, A., Gosselin, J., Hertel, A., Kindberg, J., Leclerc, M., Pelletier, F., Steyaert, S.M.J.G., Støen, O.-G., Van de Walle, J., Zedrosser, A., Swenson, J.E., 2017. Indirect effects of bear hunting: a review from Scandinavia. Ursus, 28(2): 150-164. DOI: 10.2192/URSU-D-16-00028.1.
Leclerc, M., Van de Walle, J., Zedrosser, A., Swenson, J.E., Pelletier, F., 2016. Can hunting data be used to estimate unbiased population parameters? A case study on brown bears. Biology letters, 12(6): 20160197. DOI: 10.1098/rsbl.2016.0197.