Van de Walle Joanie

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Van de Walle
First Name
Joanie
ORCID
0000-0002-5137-1851

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Author: Jenouvrier, Stephanie × Author: Pelletier, Fanie × Has files: Yes ×

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  • Article
    The interplay between hunting rate, hunting selectivity, and reproductive strategies shapes population dynamics of a large carnivore
    (Wiley Open Access, 2021-05-05) Van de Walle, Joanie ; Pelletier, Fanie ; Zedrosser, Andreas ; Swenson, Jon E. ; Jenouvrier, Stephanie ; Bischof, Richard
    Harvest, through its intensity and regulation, often results in selection on female reproductive traits. Changes in female traits can have demographic consequences, as they are fundamental in shaping population dynamics. It is thus imperative to understand and quantify the demographic consequences of changes in female reproductive traits to better understand and anticipate population trajectories under different harvest intensities and regulations. Here, using a dynamic, frequency-dependent, population model of the intensively hunted brown bear (Ursus arctos) population in Sweden, we quantify and compare population responses to changes in four reproductive traits susceptible to harvest-induced selection: litter size, weaning age, age at first reproduction, and annual probability to reproduce. We did so for different hunting quotas and under four possible hunting regulations: (i) no individuals are protected, (ii) mothers but not dependent offspring are protected, (iii) mothers and dependent offspring of the year (cubs) are protected, and (iv) entire family groups are protected (i.e., mothers and dependent offspring of any age). We found that population growth rate declines sharply with increasing hunting quotas. Increases in litter size and the probability to reproduce have the greatest potential to affect population growth rate. Population growth rate increases the most when mothers are protected. Adding protection on offspring (of any age), however, reduces the availability of bears for hunting, which feeds back to increase hunting pressure on the nonprotected categories of individuals, leading to reduced population growth. Finally, we found that changes in reproductive traits can dampen population declines at very high hunting quotas, but only when protecting mothers. Our results illustrate that changes in female reproductive traits may have context-dependent consequences for demography. Thus, to predict population consequences of harvest-induced selection in wild populations, it is critical to integrate both hunting intensity and regulation, especially if hunting selectivity targets female reproductive strategies.
  • Article
    Individual life histories: neither slow nor fast, just diverse
    (The Royal Society, 2023-07-05) Van de Walle, Joanie ; Fay, Remi ; Gaillard, Jean-Michel ; Pelletier, Fanie ; Hamel, Sandra ; Gamelon, Marlene ; Barbraud, Christophe ; Blanchet, F. Guillaume ; Blumstein, Daniel T. ; Charmantier, Anne ; Delord, Karine ; Larue, Benjamin ; Martin, Julien G.A. ; Mills, James A. ; Milot, Emmanuel ; Mayer, Francine M. ; Rotella, Jay ; Saether, Bernt-Erik ; Teplitsky, Celine ; van de Pol, Martijn ; Van Vuren, Dirk H. ; Visser, Marcel E. ; Wells, Caitlin P. ; Yarrall, John ; Jenouvrier, Stephanie
    The slow–fast continuum is a commonly used framework to describe variation in life-history strategies across species. Individual life histories have also been assumed to follow a similar pattern, especially in the pace-of-life syndrome literature. However, whether a slow–fast continuum commonly explains life-history variation among individuals within a population remains unclear. Here, we formally tested for the presence of a slow–fast continuum of life histories both within populations and across species using detailed long-term individual-based demographic data for 17 bird and mammal species with markedly different life histories. We estimated adult lifespan, age at first reproduction, annual breeding frequency, and annual fecundity, and identified the main axes of life-history variation using principal component analyses. Across species, we retrieved the slow–fast continuum as the main axis of life-history variation. However, within populations, the patterns of individual life-history variation did not align with a slow–fast continuum in any species. Thus, a continuum ranking individuals from slow to fast living is unlikely to shape individual differences in life histories within populations. Rather, individual life-history variation is likely idiosyncratic across species, potentially because of processes such as stochasticity, density dependence, and individual differences in resource acquisition that affect species differently and generate non-generalizable patterns across species.