Marc Bélisle

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Intensification of farming practices is a key factor in population declines of many species, including aerial insectivores. Of these species, Tree Swallow populations have been declining rapidly in Canada, likely in response to increased pesticide use (depleting insect prey) and destruction of marginal habitats (limiting cavity-nesting opportunities).(More)
Foraging animals are influenced by the distribution of food resources and predation risk that both vary in space and time. These constraints likely shape trade-offs involving time, energy, nutrition, and predator avoidance leading to a sequence of locations visited by individuals. According to the marginal-value theorem (MVT), a central-place forager must(More)
Evaluating the contribution of individual and environmental determinants of reproductive success is essential to improve our understanding of sexual selection. In socially monogamous bird species with high rates of extrapair paternity, traits or environmental contexts affecting the number of within-pair young (WPY) produced by males can differ from those(More)
Measuring landscape connectivity in ways that reflect an animal’s propensity or reluctance to move across a given landscape is key for planning effective conservation strategies. Resistance distance, based on circuit theory, is one such measure relevant for modeling how broad-scale animal movements over long time periods may lead to gene flow across the(More)
Impacts of agriculture practices are documented at every ecosystem level from landscape structure to biodiversity. Birds are especially affected by agricultural modifications as shown by the decline of farmland species in Europe and North America. Few studies have assessed the effects of such modifications on individual characteristics directly influencing(More)
Dispersal affects processes as diverse as habitat selection, population growth, and gene flow. Inference about dispersal and its variation is thus crucial for assessing population and evolutionary dynamics. Two approaches are generally used to estimate dispersal in free-ranging animals. First, multisite capture-recapture models estimate movement rates among(More)
Evolutionary ecologists have long been interested by the link between different immune defenses and fitness. Given the importance of a proper immune defense for survival, it is important to understand how its numerous components are affected by environmental heterogeneity. Previous studies targeting this question have rarely considered more than two immune(More)
Temporally replicated studies are essential to describe and understand selection in natural populations. Selection patterns can differ among life stages representing different fitness components. Despite the increasing number of long-term studies, yearly estimates of fluctuation in strength and direction are mostly available from studies conducted on a(More)
Resource defense behavior is often explained by the spatial and temporal distribution of resources. However, factors such as competition, habitat complexity, and individual space use may also affect the capacity of individuals to defend and monopolize resources. Yet, studies frequently focus on one or two factors, overlooking the complexity found in natural(More)
Conspicuous coloration in males of numerous bird species has been related to sexual selection. However, iridescent coloration is a complex trait that has received little attention despite its potential importance as a signal of individual condition. Directionality, the change in brightness when the animal moves under direct sunlight, has never been linked(More)