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Fortin D.,Laval University | Buono P.-L.,University Laval | Buono P.-L.,University of Ontario Institute of Technology | Schmitz O.J.,The New School | And 8 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2015

Trophic interactions in multiprey systems can be largely determined by prey distributions. Yet, classic predator–prey models assume spatially homogeneous interactions between predators and prey. We developed a spatially informed theory that predicts how habitat heterogeneity alters the landscape-scale distribution of mortality risk of prey from predation, and hence the nature of predator interactions in multiprey systems. The theoretical model is a spatially explicit, multiprey functional response in which species-specific advection–diffusion models account for the response of individual prey to habitat edges. The model demonstrates that distinct responses of alternative prey species can alter the consequences of conspecific aggregation, from increasing safety to increasing predation risk. Observations of threatened boreal caribou, moose and grey wolf interacting over 378 181 km2 of human-managed boreal forest support this principle. This empirically supported theory demonstrates how distinct responses of apparent competitors to landscape heterogeneity, including to human disturbances, can reverse density dependence in fitness correlates. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Lavoie M.,Laval University | Blanchette P.,Direction de la faune terrestre et de lavifaune | Tremblay J.P.,Laval University | Lariviere S.,Cree Hunters and Trappers Income Security Board
Wildlife Society Bulletin | Year: 2014

We compared 2 net-propelled devices to capture eastern wild turkeys (Meleagris gallopavo silvestris). One device, the rocket-net, employs explosives for propulsion and is currently the most effective and widespread method used to capture this species. The second device, the net blaster, works with compressed air instead of explosives. During 2009-2012, we captured 344 wild turkeys using rocket-nets (n=30 attempts) and net blasters (n=15 attempts). Both devices had a similar capture success rate; but malfunctioning was twice as common with the rocket-net as with the net blaster, as was the rate of injuries to captured wild turkeys. However, rocket-nets did not have a higher rate of capture-related mortality. The net blaster was more difficult to handle, more expensive, and did not work when temperatures were below 208C. Overall the net blaster proved to be more efficient capturing wild turkeys and was safer than the rocket-net. © 2013 The Wildlife Society.

Leblond M.,University of Quebec at Rimouski | Dussault C.,Direction de la faune terrestre et de lavifaune | St-Laurent M.-H.,University of Quebec at Rimouski
Biological Conservation | Year: 2014

The long-term persistence of boreal caribou (Rangifer tarandus caribou) is threatened by the negative impacts of human activities, including industrial development. The vast geographical distribution and behavioural variability of caribou warranted the development and validation of an appropriate conservation tool for managers in eastern Canada. We developed a habitat suitability model for boreal caribou in Québec by integrating expert knowledge into a hierarchical analysis. We elicited responses from 14 experts on caribou ecology to determine the best spatiotemporal scales of application, the relative importance of habitat variables, the zone of influence of human infrastructure, and the parameterization of the model. Based on this input, we built the model using 8 habitat categories and 3 human infrastructure variables. Experts identified mature conifer-dominated forests and open lichen woodlands as the most important vegetation categories for boreal caribou, whereas density of and proximity to paved roads, forest roads, and mines decreased habitat quality. We mapped the resulting model over the entire province of Québec (up to the northern forest allocation limit), and validated it using independent GPS telemetry datasets acquired in 3 distinct regions. Our model predicted that habitat suitability was highest in the northeastern part of our study area, where timber harvest activities and roads were virtually absent. Conversely, southern parts of Québec were generally unsuitable for boreal caribou. Our habitat suitability model is among the first tools for boreal caribou conservation available to wildlife and land managers in Québec. © 2014 Elsevier Ltd.

Yannic G.,Laval University | Pellissier L.,University of Fribourg | Le Corre M.,Laval University | Dussault C.,Direction de la faune terrestre et de lavifaune | And 2 more authors.
Proceedings. Biological sciences / The Royal Society | Year: 2014

Landscape heterogeneity plays a central role in shaping ecological and evolutionary processes. While species utilization of the landscape is usually viewed as constant within a year, the spatial distribution of individuals is likely to vary in time in relation to particular seasonal needs. Understanding temporal variation in landscape use and genetic connectivity has direct conservation implications. Here, we modelled the daily use of the landscape by caribou in Quebec and Labrador, Canada and tested its ability to explain the genetic relatedness among individuals. We assessed habitat selection using locations of collared individuals in migratory herds and static occurrences from sedentary groups. Connectivity models based on habitat use outperformed a baseline isolation-by-distance model in explaining genetic relatedness, suggesting that variations in landscape features such as snow, vegetation productivity and land use modulate connectivity among populations. Connectivity surfaces derived from habitat use were the best predictors of genetic relatedness. The relationship between connectivity surface and genetic relatedness varied in time and peaked during the rutting period. Landscape permeability in the period of mate searching is especially important to allow gene flow among populations. Our study highlights the importance of considering temporal variations in habitat selection for optimizing connectivity across heterogeneous landscape and counter habitat fragmentation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Leblond M.,University of Quebec at Rimouski | Dussault C.,Direction de la faune terrestre et de lavifaune | St-Laurent M.-H.,University of Quebec at Rimouski
Forest Ecology and Management | Year: 2015

Several North American jurisdictions are adopting new forest management practices that favor sustainable development and biodiversity conservation, but that are also expected to reduce timber yield. In many regions, forest managers have identified areas of intensive timber production where spruce plantations and thinning treatments are to be used extensively. Concomitantly, wildlife managers are concerned that intensive silvicultural treatments will have a negative impact on sport hunting by modifying the behavior and abundance of game species. We evaluated whether an experimental low-density spruce plantation (1350stems/ha) could increase habitat suitability for moose Alces americanus compared to standard high-density plantations currently used throughout eastern Canada (~2000stems/ha). We evaluated the effects of plantation type, pre-commercial thinning, and age class of plantations on proxies of habitat suitability and use by moose in a northeastern temperate forest of Bas-Saint-Laurent, Québec (Canada). We also considered various environmental characteristics measured locally and within 3.14-km2 landscape contexts to explain spatial variations in use by moose among 540 sampling plots. Our results show that the proportion of stems browsed by moose increased with the number of available stems and decreased with vertical cover. The number of moose feces, an index of time spent by moose in sampling plots, was similar in both plantation types, but was lower in thinned and young (5years old) stands as compared to unthinned and 15years old stands. Variations in the proportion of browsed stems and the number of feces were not explained by broad-scale indices of food availability, density of edges between stands offering good cover and foraging opportunities, road density, elevation, or the area occupied by plantations and naturally regenerated stands around sampling plots. Moose used low-density plantations significantly more than standard plantations for browsing, and these stands supported higher stem densities and vertical cover than standard high-density plantations on average. Low-density plantations offered good foraging opportunities for moose by allowing a large variety of palatable deciduous species to grow between planted coniferous stems. However, we found high inter-site variability in environmental characteristics following plantation, even among equivalent treatments. This suggests that forest managers should aim for particular stand characteristics (i.e. high availability of stems and low vertical cover) in situ rather than prescribing specific post-harvest silvicultural treatments (e.g., plantation types) to favor moose. We recommend the use of unthinned low-density plantations in northern temperate regions where the management objective is to maintain high moose hunting success. © 2015 Elsevier B.V.

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