ProjectInfluence of the energetic value and nutritional quality of preys on the feeding effort and reproductive success of chickadees considering the parents’ personality
Since 2009, François Vézina's team has been conducting research on forest birds in the Macpès Teaching and Research Forest (FER) in Quebec, Canada. This research is part of a broader program that aims to understand the mechanisms that limit phenotypic flexibility in birds during periods of increased energy demand and to determine the consequences of these limits on the fitness. Birds are studied during the breeding season, from May to August. This research project focuses on the influence of the emergence dynamics of the entomofauna and the abiotic spring constraints on the reproduction of forest birds. In nesting birds, the chick-feeding period is generally considered to be the most demanding of the annual cycle in terms of energy expenditure. The strategy of exploiting the food resources and the effort invested by the parents in the feeding of the offspring are thus affecting the fitness by directly influencing the parental contribution to the next generation in addition to the survival rate of the chicks and adults. However, there’s a large individual variation in the feeding rate that, surprisingly, is often independent of the mass of chicks or the number of chicks fledged. It’s important to note that much of the studies on the subject don’t report prey data or the energy and nutritional value of these prey items. We suggest that there’s a great variation in the type of prey reported from one area of the forest to the other, which implies that the nutritional value of these preys is also variable. Our measurement of the feeding rate may therefore be incomplete if the birds adjust their effort according to the quality of the preys. For the same reproductive success, the adults considered better could exploit areas with prey containing more energy and nutrients, and work at a lower rate while individuals operating the sites with less prey or prey of lower nutritional quality could compensate by increasing the feeding rate. In chickadees, more aggressive individuals may have a priority access to available resources. Also, more explorative individuals may find better prey for their offspring. It’s therefore interesting to check whether the success of the parents according to their personality is related to the quality of the prey supply in their habitat and to the rate of growth of the chicks. The objective of my master’s project is to determine how the energy value and nutritional quality of prey influences parental feeding effort, parental reproductive success, and chick growth rate, and how this exploitation of resources and productivity may be related to the parents’ personality.