I am a researcher in ecology. My work focuses on the population ecology and evolution of life history traits of herbivorous mammals. I have been particularly interested in the effects of sexual selection on population dynamics and life history tactics
I pay a special attention to the application of my results to wildlife management, mainly of ungulate species through a close collaboration with researchers from the ONCFS
- Life-history tactics of roe deer in a highly constraining environment, with Jean-Michel Gaillard & Floriane Plard
- Red deer habitat selection on the Western Coast of Norway - with Atle Mysterud & Leif Egil Loe
- Impact of climate change on Alpine marmots, with Aurélie Cohas
- Estimation of reproductive success of female red deer at La Petite Pierre, France - with Jean-Luc Hamann & Maryline Pellerin
- Rutting behaviour of roe deer from geolocation data, with Nicolas Morellet & Atle Mysterud
- Urban ecology of the European red squirrel in the Tête d'Or Parc, Lyon, France with Aurélie Cohas
May 2014 - Our paper on the impact of climate change on
roe deer demography makes the front page
Letters's special issue. Roe deer is becoming famous!
March 20th 2014 - A short newspaper published by 'Le
Monde' about the roe deer project at Chizé,
Étudiants M2 pro -- proposition de stage sur les risques de collisions entre véhicules et grande faune, avec Christine Saint-Andrieux et Maryline Pellerin de l'ONCFS. March. 2013 - Ecology front page! Our paper by Marion Tafani about climate change and Alpine marmot life-histories will illustrate the front page of Ecology in the issue of March!
Feb. 2013 - A French TV will be shooting a roe deer capture session at Chizé.
Feb. 2013 - Lucille Palazy successfully defended her PhD on the 12th of February about trophy hunting and Allee effect in mammals. Congratulations!
Jan. 2013 - First captured roe deer at Chizé on the 5th of January.
Jun. 2012 - Garden Party at the CEBC to celebrate the end of a successful roe deer catching session. Event highlighted in the Courrier de l'Ouest, a local newspaper.
Jan. 2012 - Animal Conservation features our paper Palazy & col. in its issue of February
Jan. 2012 - France 3 will be shooting a roe deer capture session at Chizé to cast on French TV
Nov. 2011 - Plaisir de la chasse (numéro 712, p. 30) highlighted our paper Milner & col. to appear in the European Journal of Wildlife Research
- Saint-Andrieux, C., Calenge, C. & Bonenfant, C. Comparison
of ecological, biological and anthropogenic causes of
vehicle–wildlife collisions among three large herbivore
Summary: Vehicle–wildlife collisions are of increasing concern in modern societies caracterized by a continous and accelerating anthropogenic development. Preventing and mitigating collisions with wildlife will require a better understanding of the environmental and biological drivers of collision risks. Because species of large mammals differ in terms of food requirements, habitat selection and movement, and activity patterns we tested whether vehicle collisions with red deer, roe deer and wild boar, the most abundant large herbivores in Europe, differed in terms of spatial distribution and explanatory factors, using a Bayesian statistical framework. From 20,275 documented collisions in 9 departments of France between years 1990 and 2006, we found marked differences in magnitude and in the most influential environmental factors accounting for the density of collisions among the three species, in agreement with their biology and habitat preferences. The effect of road density was higher for the red deer than for the two other species for which it was similar, and did not level off at our large spatial-scale of observation. As expected from particle collision models, the annual hunting harvest — interpreted as a proxy of population abundance — was positively associated with the density of collisions for all species, being the strongest for red deer. Overall, the effect of landscape structure on the density of collisions was weak but while the collision density did decrease with the proportion of forest in a management unit for wild boar, it increased with the fragmentation of forests for red deer that commute among forest patches between day and night. To reduce the number of vehicle–wildlife collisions actively, our results suggest to generalise road fencing for highways and motorways or a reduction of abundance of large herbivore populations as efficient action means. Overall, we call for of a greater consideration of the species' biology in information campaigns or by using specific road signs.
- Bischof, R., Bonenfant, C., Rivrud, I.M., Zedrosser, A.,
Friebe, A., Coulson, T.N., Mysterud, A. & Swenson,
J.E. (2018) Regulated hunting re-shapes the life
history of brown bears. Nature Ecology &
Summary: Management of large carnivores is among the most controversial topics in natural resource administration. Regulated hunting is a centrepiece of many carnivore management programmes and, although a number of hunting effects on population dynamics, body-size distributions and life history in other wildlife have been observed, its effects on life history and demography of large carnivores remain poorly documented. We report results from a 30-year study of brown bears (Ursus arctos) analysed using an integrated hierarchical approach. Our study revealed that regulated hunting has severely disrupted the interplay between age-specific survival and environmental factors, altered the consequences of reproductive strategies, and changed reproductive values and life expectancy in a population of the world's largest terrestrial carnivore. Protection and sustainable management have led to numerical recovery of several populations of large carnivores, but managers and policymakers should be aware of the extent to which regulated hunting may be influencing vital rates, thereby reshaping the life history of apex predators.
- Riotte-Lambert, L., Benhamou, S., Bonenfant, C. &
Jamaillé-Jammes, S. (2017) Spatial memory shapes
density dependence in population dynamics. The
Proceedings of the Royal Society B: Biological
Summary: Most population dynamics studies assume that individuals use space uniformly, and thus mix well spatially. In numerous species, however, individuals do not move randomly, but use spatial memory to visit renewable resource patches repeatedly. To understand the extent to which memory-based foraging movement may affect density-dependent population dynamics through its impact on competition, we developed a spatially explicit, individual-based movement model where reproduction and death are functions of foraging efficiency. We compared the dynamics of populations of with-and without-memory individuals. We showed that memory-based movement leads to a higher population size at equilibrium, to a higher depletion of the environment, to a marked discrepancy between the global (i.e. measured at the population level) and local (i.e. measured at the individual level) intensities of competition, and to a nonlinear density dependence. These results call for a deeper investigation of the impact of individual movement strategies and cognitive abilities on population dynamics.
- Pellerin, M., Bessière, A., Maillard, D., Capron, G.,
Gaillard, J.-M., Michallet, J. & Bonenfant,
C. (2017) Saving time and money by using diurnal
vehicle counts to monitor roe deer
abundance. Wildlife Biology,
Summary: Despite being a widespread and important game species in Europe, scientifically reliable, easy applicable and cost effective methods for monitoring abundance of roe deer Capreolus capreolus populations do not yet exist. The currently recommended kilometric index (AI-p) captures temporal variation in the relative abundance of populations; however, because this index is carried out on foot, it is demanding in terms of sampling effort and difficult to apply at spatial scales of several hundred km(2) typical of deer management units. Here, we propose and test a modified version of the kilometric index by using a vehicle to carry out transects over large areas (AI-v). To validate this abundance index, we compared variation in population abundance estimated with AI-p and AI-v with capture-mark-recapture (CMR) estimates of population density in a roe deer population, Chize (France), monitored for 24 years (including eight years when both indices were collected). We found no detectable effect of conditions of observation (temperature and precipitation) on either AI-p or AI-v. AI-p and AI-v were both positively and linearly related (on a log scale) to CMR estimates of population density, after accounting for uncertainty of CMR estimates by using a bootstrap procedure. AI-p was slightly better correlated to population density (r = 0.76) than AI-v (r = 0.58). The positive correlation of AI-p and AI-v with CMR density estimates as well as the reduced costs of conducting surveys by car instead on foot (-47%) suggest that diurnal vehicle counts of roe deer can provide a suitable abundance index to monitor temporal trends in roe deer populations at operational management scales. For reliable management of wildlife populations, diurnal vehicle counts of roe deer could be used in association with measures of animal performance and herbivore impacts on the habitat, within the framework of the indicators of ecological change.
- Briggs-Gonzales, V., Bonenfant, C., Basille, M.,
Cherkiss, M., Beauchamp, J. & Mazzoti,
F. (2017) Life histories and conservation of
long-lived reptiles, an illustration with the American
crocodile (Crocodylus acutus). Journal of
Animal Ecology, 86,
Summary: Successful species conservation is dependent on adequate estimates of population dynamics, but age-specific demographics are generally lacking for many long-lived iteroparous species such as large reptiles. Accurate demographic information -allows estimation of population growth rate, as well as projection of future population sizes and quantitative analyses of fitness trade-offs involved in the evolution of life-history strategies. Here, a long-term capture-recapture study was conducted from 1978 to 2014 on the American crocodile (Crocodylus acutus) in southern Florida. Over the study period, 7,427 hatchlings were marked and 380 individuals were recaptured for as many as 25 years. We estimated survival to be strongly age dependent with hatchlings having the lowest survival rates (16%) but increasing to nearly 90% at adulthood based on mark-recapture models. More than 5% of the female population were predicted to be reproductive by age 8 years; the age-specific proportion of reproductive females steadily increased until age 18 when more than 95% of females were predicted to be reproductive. Population growth rate, estimated from a Leslie-Lefkovitch stage-class model, showed a positive annual growth rate of 4% over the study period. Using a prospective sensitivity analysis, we revealed that the adult stage, as expected, was the most critical stage for population growth rate; however, the survival of younger crocodiles before they became reproductive also had a surprisingly high elasticity. We found that variation in age-specific fecundity has very limited impact on population growth rate in American crocodiles. We used a comparative approach to show that the original life-history strategy of American crocodiles is actually shared by other large, long-lived reptiles: while adult survival rates always have a large impact on population growth, this decreases with declining increasing growth rates, in favour of a higher elasticity of the juvenile stage. Crocodiles, as a long-lived and highly fecund species, deviate from the usual association of life histories of "slow" species. Current management practices are focused on nests and hatchling survival; however, protection efforts that extend to juvenile crocodiles would be most effective for conservation of the species, especially in an ever-developing landscape.
- Hurley, M., Hebblewhite, M., Lukacs, P.M., Nowak, J.J.,
Gaillard, J.-M. & Bonenfant,
C. (2017) Regional-scale models for predicting
overwinter survival of juvenile
ungulates. Journal of Wildlife Management,
81, 364--378. [pdf]
Summary: Juvenile survival is highly variable in ungulate populations and often influences their dynamics. However, this vital rate is difficult to estimate with common wildlife management methods. Yet managers would benefit from being able to predict juvenile survival to reliably assess population dynamics for harvest management. In the case of mule deer (Odocoileus hemionus), previous studies reported that overwinter survival is the demographic parameter that influences population dynamics. We predicted winter survival of mule deer fawns under a range of habitat quality, weather, and predation regimes. We modeled overwinter survival of 2,529 fawns within 11 Population Management Units (PMU) in Idaho, 2003-2013. We used remotely sensed Normalized Difference Vegetation Index (NDVI) as a measure of summer plant productivity and both Moderate Resolution Infrared Spectroscopy Snow Data (MODIS SNOW) and the modeled Snow Data Assimilation System (SNODAS) as measures of winter snow conditions to capture spatiotemporal variation in winter survival. We used Bayesian hierarchical models to estimate survival, including covariates at the appropriate spatial and temporal resolution for each level: individual, capture site, PMU, and ecotype scales. We evaluated the predictive capacity of models using internal validation and external (out-of-sample) validation procedures comparing non-parametric Kaplan-Meier (KM) survival estimates with estimates from Bayesian hierarchical models. Statewide survival of fawns from 16 December to 1 June ranged from 0.32 to 0.71 during 2003 to 2013, with relatively low survival in 2006, 2008, and 2011 in most Game Management Units. Survival for individualPMUs ranged from 0.09 in theWeiser-McCallPMUin 2011 to 0.95 in the same PMU in 2005. Internal validation revealed models predictedKMsurvival well, over a range of R-2 from 0.78 to 0.82, with the most complex model explaining the most variance as expected. However, because our goal was to predict winter survival of mule deer in the future, we evaluated our candidate models by withholding 2 years of data and then predicted those years with each model. The best-supported predictive model was our simplest model with 3 covariates, accounting for 71% of the variance in withheld years. Forage quality in late summerfall increased winter mule deer survival, whereas early and late winter snow cover decreased survival. At finerspatial scales within ecotypes, our internal validation was slightly better in aspen (0.86), similar in conifer (0.80), and poorer in shrub-steppe (0.60) ecotypes than our best statewide overall survival models, which accounted for 82% of the variance. Our analyses demonstrate the generality versus precision tradeoff across ecotypes and spatial scales to understand the extent that our survival models may be applied to different landscapes with varied predator communities, climate, and plant nutrition.