Éric Baubet - Academia.edu (original) (raw)

Papers by Éric Baubet

Research paper thumbnail of Efficient use of harvest data: An integrated population model for exploited animal populations

Many populations are affected by hunting or fishing. Models designed to assess the sustainability... more Many populations are affected by hunting or fishing. Models designed to assess the sustainability of harvest management require accurate estimates of demographic parameters (e.g. survival, reproduction) hardly estimable with limited data collected on exploited populations. The joint analysis of different data sources with integrated population models (IPM) is an optimal framework to obtain reliable estimates for parameters usually difficult to estimate, while accounting for imperfect detection and observation error. The IPM built so far for exploited populations have integrated count-based surveys and catch-at-age data into age-class structured population models. But the age of harvested individuals is difficult to assess and often not recorded, and population counts are often not performed on a regular basis, limiting their use for the monitoring of exploited populations. Here, we propose an IPM that makes efficient use of data commonly collected in exploited marine and terrestrial...

Research paper thumbnail of Effects of pulsed resources on the dynamics of seed consumer populations: a comparative demographic study in wild boar

Research paper thumbnail of Efficient use of harvest data: a size‐class‐structured integrated population model for exploited populations

Research paper thumbnail of How does increasing mast seeding frequency affect population dynamics of seed consumers? Wild boar as a case study

Research paper thumbnail of How does increasing mast seeding frequency affect population dynamics of seed consumers? Wild boar as a case study

Ecological Applications, Apr 16, 2020

Research paper thumbnail of du Sanglier en milieu forestier de plaine agricole

Research paper thumbnail of Adaptation D'Un Collier Émetteur Extensible Pour Sanglier

Research paper thumbnail of Diet of the wild boar in the French Alps

In France, as in many other European countries, the wild boar (Sus scrofa) population has increas... more In France, as in many other European countries, the wild boar (Sus scrofa) population has increased rapidly in the last decade. Since 1990, mountainous areas have been particularly affected by the phenomenon. The growth of the wild boar population has led to an increase in the damages caused to meadows by the rooting activities of the animals. At the same time, little is known about the biology of wild boar in high elevation areas. A three-year study was undertaken to understand the relationship between the diet of wild boar and damages to meadows. Diet analyses are based on faecal and stomach content samples (n = 352) collected in two years (from April 1994 to April 1996). We observed strong variations in the composition of the diet throughout the year, both monthly and seasonally. All of these effects were related to food availability. Specific analyses of earthworm consumption by wild boar showed the considerable importance of those items in the wild boar diet in mountainous areas. We could not establish a relationship between earthworm consumption and belowground vegetation. Our results suggest that the rooting activities by wild boar are not directed solely toward earthworms.

Research paper thumbnail of Can wild boar be surveyed using GPS?

The Global Positioning System (GPS) is an important new technology for spa- tial behaviour studie... more The Global Positioning System (GPS) is an important new technology for spa- tial behaviour studies of terrestrial vertebrates. Although VHF telemetry has been substan- tially used, our study is the first report, to our knowledge, on GPS technology used to track free-ranging wild boars. Although the need for collars larger than those used for VHF track- ing, the crowded vegetation

Research paper thumbnail of Mortality rates of wild boar in Europe as a tool for wild boar management

In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is ... more In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is accompanied by economic problems. Due to underestimation of population densities and reproduction rates harvest rates seem to be insufficient, especially proportions of shot females might be inadequate. Thus, we calculated mortality rates of several wild boar populations, to show the efficiency of hunting within 13 years from studies conducted in 16 different study areas distributed over 8 European states. For calculating mortality rates the daily probability of survival of radio telemetrically observed wild boar were analysed according to Mayfield (1961) for three age classes (0, 1, ≥2years) and both sexes. Of 872 animals observed by VHF- or GPS-telemetry 228 died during the total observation of 121998 days. The mortality rates of wild boar, especially piglets were low (about 0.5). About three third of all observed animals survived at least until the next period of reproduction. The sex...

Research paper thumbnail of Mortality rates of wild boar Sus scrofa L. in central Europe

European Journal of Wildlife Research, 2013

In many parts of Europe, wild boar Sus scrofa population increase, and thus, high densities and d... more In many parts of Europe, wild boar Sus scrofa population increase, and thus, high densities and dispersal into new areas are accompanied by economic problems. Due to many factors like insufficient hunting strategies as well as underestimation of population densities and reproduction rates, harvest rates seem to be insufficient. Thus, we calculated mortality rates of several wild boar populations from 1998 to 2009, to show the efficiency of hunting within several studies distributed over eight European states. For calculating mortality rates, the daily probability of survival of radio telemetrically observed wild boar was analysed according to Mayfield (Wilson Bull 73:255-261, 1961) and with survival analysis in R for three age classes (0, 1, ≥2 years) and both sexes. The mortality rates of wild boar per annum, especially piglets, were comparably low (about 0.5 for piglets and similar for total population). About three third of all observed animals survived at least until the next period of reproduction. Mortality rates differed between some study areas, the sexes and age classes. The sex ratio of the shot piglets equals the sex ratio of captured piglets; there seems to be no sex-biased Communicated by C. Gortázar

Research paper thumbnail of Comportement du sanglier en réponse à la pression de chasse Influence des "réserves" sur son occupation de l'espace

Les zones de quiétude (réserves de chasse, réserves naturelles, camps militaires ou zones peu cha... more Les zones de quiétude (réserves de chasse, réserves naturelles, camps militaires ou zones peu chassées…etc) modifient sans doute la perception qu'a le sanglier de son environnement. Il est très probable que de telles surfaces permettent aux animaux de se soustraire au ...

Research paper thumbnail of Améliorer la connaissance du fonctionnement démographique des populations de sangliers : vers une meilleure gestion de l'espèce Sus scrofa

Research paper thumbnail of La modélisation démographique : un outil d’aide à la gestion du sanglier ?

Une étude de la population de sangliers du site expérimental de Châteauvillain – Arc-en-Barrois (... more Une étude de la population de sangliers du site expérimental de Châteauvillain – Arc-en-Barrois (52), basée sur la modélisation de sa démographie, a été mise en oeuvre en 2005. Appliqué à cette population en particulier, le modèle s’est avéré être un outil prometteur pour sa gestion. L’idée sous-jacente est d’essayer d’identifier et de comprendre les facteurs à l’origine des variations d’effectifs observées sur le terrain. Par ailleurs, ce type d’approche permet aussi de suggérer des mesures de prélèvements quantitatives et qualitatives au sein de la population pour atteindre l’objectif de gestion souhaité. Il reste maintenant à tester son intérêt dans des conditions plus représentatives de la réalité dans notre pays, à savoir sur des territoires où la connaissance de la dynamique des populations est moins détaillée. Cet article relate ainsi la première application de ce modèle dans des conditions plus classiques de gestion, à l’échelle d’un département, le Doubs.

Research paper thumbnail of Linking demographic responses and life history tactics from longitudinal data in mammals

Oikos, 2015

ABSTRACT In stochastic environments, a change in a demographic parameter can influence the popula... more ABSTRACT In stochastic environments, a change in a demographic parameter can influence the population growth rate directly or via a resulting impact on age structure. Stochastic elasticity of the long-run stochastic growth rate λs to a demographic parameter offers a suitable way to measure the overall demographic response because it includes both the direct effect of changing the demographic parameter and its indirect effect through changes in the age structure. From 25 mammalian populations with contrasting life histories, we investigated how pace of life and population growth rate influence the demographic responses (measured as the relative contributions of the direct and indirect components of stochastic elasticity on λs). We found that in short-lived species, the change in population structure resulting from an increase in yearling survival leads to an additional increase in λs, whereas in long-lived species, the same change in population structure leads to a decrease. Short-lived species thus display a boom-bust life history strategy contrary to long-lived species, for which the long lifespan dampens the demographic consequences of changing age structure. Irrespective of the species’ life history strategy, the change in population age structure resulting from an increase in adult survival leads to an additional increase in λs due to an increase of the proportion of mature individuals in the population. On the contrary, a change in population age structure resulting from an increase of reproductive performance leads to a decrease in λs that is due to the increase of the proportion of immature individuals in the population. Our comparative analysis of stochastic elasticity patterns in mammals shows the existence of different demographic responses to changes in age structure between short- and long-lived species, which improves our understanding of population dynamics in variable environments in relation to the species-specific pace of life.

Research paper thumbnail of Mortality rates of wild boar in Europe as a tool for wild boar management

In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is ... more In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is accompanied by economic problems. Due to underestimation of population densities and reproduction rates harvest rates seem to be insufficient, especially proportions of shot females might be inadequate. Thus, we calculated mortality rates of several wild boar populations, to show the efficiency of hunting within 13 years from studies conducted in 16 different study areas distributed over 8 European states. For calculating mortality rates the daily probability of survival of radio telemetrically observed wild boar were analysed according to Mayfield (1961) for three age classes (0, 1, ≥2years) and both sexes. Of 872 animals observed by VHF- or GPS-telemetry 228 died during the total observation of 121998 days. The mortality rates of wild boar, especially piglets were low (about 0.5). About three third of all observed animals survived at least until the next period of reproduction. The sex...

Research paper thumbnail of Variations saisonnières du potentiel de dispersion des plantes par les ongulés sauvages

Le potentiel de disperser à longue distance est déterminant pour expliquer les migrations passées... more Le potentiel de disperser à longue distance est déterminant pour expliquer les migrations passées et la distribution actuelle des plantes ainsi que pour prédire leur répartition future, notamment sous la contrainte des changements globaux. Les animaux, le vent, l'eau et les activités humaines sont les principaux vecteurs qui pourraient permettre aux plantes d'accompagner le rythme actuel et futur des changements prédits. Nous nous sommes intéressés aux variations saisonnières du potentiel de dispersion des plantes par endozoochorie, en utilisant comme modèles trois espèces communes d'ongulés sauvages : le chevreuil, le cerf et le sanglier. Tout d’abord, nous avons estimé le temps de rétention interne de graines de 3 plantes proposées à des animaux en semi-captivité. Nous avons quantifié le temps écoulé depuis leur ingestion jusqu'à leur libération dans les fèces en identifiant les graines excrétées pendant 48 heures. Nous avons ensuite quantifié les distances moyenne...

Research paper thumbnail of Seasonal and annual variations in earthworm consumption by wild boar (Sus scrofa scrofa L.)

Wildlife Research, 2003

We investigated the annual and monthly patterns of earthworm consumption by wild boar in the Maur... more We investigated the annual and monthly patterns of earthworm consumption by wild boar in the Maurienne valley (Alps, France). A positive correlation (R 2 = 0.79) was found between weather conditions and patterns of earthworm consumption. A positive correlation was also found between earthworm consumption rates and the occurence of 'worm nights', an easy and direct measure of earthworm availability. W R 0 0 1 1 3 E a r t h wo r m c o n s u mp t i o n b y w i l d b o a r E . B a u b e t e t a l .

Research paper thumbnail of Connaissances sur la biologie du sanglier: Utilisation de l'espace et régime alimentaire

CITATIONS 3 READS 456 4 authors, including: Some of the authors of this publication are also work... more CITATIONS 3 READS 456 4 authors, including: Some of the authors of this publication are also working on these related projects: Parasitism and spatial genetic structure.Example of the Mediteranean Mouflon (Ovis gmelini musimon x Ovis sp.). View project The user has requested enhancement of the downloaded file.

Research paper thumbnail of Influence of harvesting pressure on demographic tactics: implications for wildlife management

Journal of Applied Ecology, 2011

1. Demographic tactics within animal populations are shaped by selective pressures. Exploitation ... more 1. Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. 2. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (k) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. 3. Asymptotic k was 1AE242 in the lightly hunted population and 1AE115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2AE63 and 1AE27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. 4. Compared with expected generation times of similar-sized ungulates (more than 6 years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3AE6 years in the lightly hunted population and only 2AE3 years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. 5. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of management strategies based on context-specific demographic models are useful for selecting interventions for population control. This type of approach allows the assessment of population response to exploitation by considering a range of plausible scenarios, improving the chance of selecting appropriate management actions.

Research paper thumbnail of Efficient use of harvest data: An integrated population model for exploited animal populations

Many populations are affected by hunting or fishing. Models designed to assess the sustainability... more Many populations are affected by hunting or fishing. Models designed to assess the sustainability of harvest management require accurate estimates of demographic parameters (e.g. survival, reproduction) hardly estimable with limited data collected on exploited populations. The joint analysis of different data sources with integrated population models (IPM) is an optimal framework to obtain reliable estimates for parameters usually difficult to estimate, while accounting for imperfect detection and observation error. The IPM built so far for exploited populations have integrated count-based surveys and catch-at-age data into age-class structured population models. But the age of harvested individuals is difficult to assess and often not recorded, and population counts are often not performed on a regular basis, limiting their use for the monitoring of exploited populations. Here, we propose an IPM that makes efficient use of data commonly collected in exploited marine and terrestrial...

Research paper thumbnail of Effects of pulsed resources on the dynamics of seed consumer populations: a comparative demographic study in wild boar

Research paper thumbnail of Efficient use of harvest data: a size‐class‐structured integrated population model for exploited populations

Research paper thumbnail of How does increasing mast seeding frequency affect population dynamics of seed consumers? Wild boar as a case study

Research paper thumbnail of How does increasing mast seeding frequency affect population dynamics of seed consumers? Wild boar as a case study

Ecological Applications, Apr 16, 2020

Research paper thumbnail of du Sanglier en milieu forestier de plaine agricole

Research paper thumbnail of Adaptation D'Un Collier Émetteur Extensible Pour Sanglier

Research paper thumbnail of Diet of the wild boar in the French Alps

In France, as in many other European countries, the wild boar (Sus scrofa) population has increas... more In France, as in many other European countries, the wild boar (Sus scrofa) population has increased rapidly in the last decade. Since 1990, mountainous areas have been particularly affected by the phenomenon. The growth of the wild boar population has led to an increase in the damages caused to meadows by the rooting activities of the animals. At the same time, little is known about the biology of wild boar in high elevation areas. A three-year study was undertaken to understand the relationship between the diet of wild boar and damages to meadows. Diet analyses are based on faecal and stomach content samples (n = 352) collected in two years (from April 1994 to April 1996). We observed strong variations in the composition of the diet throughout the year, both monthly and seasonally. All of these effects were related to food availability. Specific analyses of earthworm consumption by wild boar showed the considerable importance of those items in the wild boar diet in mountainous areas. We could not establish a relationship between earthworm consumption and belowground vegetation. Our results suggest that the rooting activities by wild boar are not directed solely toward earthworms.

Research paper thumbnail of Can wild boar be surveyed using GPS?

The Global Positioning System (GPS) is an important new technology for spa- tial behaviour studie... more The Global Positioning System (GPS) is an important new technology for spa- tial behaviour studies of terrestrial vertebrates. Although VHF telemetry has been substan- tially used, our study is the first report, to our knowledge, on GPS technology used to track free-ranging wild boars. Although the need for collars larger than those used for VHF track- ing, the crowded vegetation

Research paper thumbnail of Mortality rates of wild boar in Europe as a tool for wild boar management

In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is ... more In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is accompanied by economic problems. Due to underestimation of population densities and reproduction rates harvest rates seem to be insufficient, especially proportions of shot females might be inadequate. Thus, we calculated mortality rates of several wild boar populations, to show the efficiency of hunting within 13 years from studies conducted in 16 different study areas distributed over 8 European states. For calculating mortality rates the daily probability of survival of radio telemetrically observed wild boar were analysed according to Mayfield (1961) for three age classes (0, 1, ≥2years) and both sexes. Of 872 animals observed by VHF- or GPS-telemetry 228 died during the total observation of 121998 days. The mortality rates of wild boar, especially piglets were low (about 0.5). About three third of all observed animals survived at least until the next period of reproduction. The sex...

Research paper thumbnail of Mortality rates of wild boar Sus scrofa L. in central Europe

European Journal of Wildlife Research, 2013

In many parts of Europe, wild boar Sus scrofa population increase, and thus, high densities and d... more In many parts of Europe, wild boar Sus scrofa population increase, and thus, high densities and dispersal into new areas are accompanied by economic problems. Due to many factors like insufficient hunting strategies as well as underestimation of population densities and reproduction rates, harvest rates seem to be insufficient. Thus, we calculated mortality rates of several wild boar populations from 1998 to 2009, to show the efficiency of hunting within several studies distributed over eight European states. For calculating mortality rates, the daily probability of survival of radio telemetrically observed wild boar was analysed according to Mayfield (Wilson Bull 73:255-261, 1961) and with survival analysis in R for three age classes (0, 1, ≥2 years) and both sexes. The mortality rates of wild boar per annum, especially piglets, were comparably low (about 0.5 for piglets and similar for total population). About three third of all observed animals survived at least until the next period of reproduction. Mortality rates differed between some study areas, the sexes and age classes. The sex ratio of the shot piglets equals the sex ratio of captured piglets; there seems to be no sex-biased Communicated by C. Gortázar

Research paper thumbnail of Comportement du sanglier en réponse à la pression de chasse Influence des "réserves" sur son occupation de l'espace

Les zones de quiétude (réserves de chasse, réserves naturelles, camps militaires ou zones peu cha... more Les zones de quiétude (réserves de chasse, réserves naturelles, camps militaires ou zones peu chassées…etc) modifient sans doute la perception qu'a le sanglier de son environnement. Il est très probable que de telles surfaces permettent aux animaux de se soustraire au ...

Research paper thumbnail of Améliorer la connaissance du fonctionnement démographique des populations de sangliers : vers une meilleure gestion de l'espèce Sus scrofa

Research paper thumbnail of La modélisation démographique : un outil d’aide à la gestion du sanglier ?

Une étude de la population de sangliers du site expérimental de Châteauvillain – Arc-en-Barrois (... more Une étude de la population de sangliers du site expérimental de Châteauvillain – Arc-en-Barrois (52), basée sur la modélisation de sa démographie, a été mise en oeuvre en 2005. Appliqué à cette population en particulier, le modèle s’est avéré être un outil prometteur pour sa gestion. L’idée sous-jacente est d’essayer d’identifier et de comprendre les facteurs à l’origine des variations d’effectifs observées sur le terrain. Par ailleurs, ce type d’approche permet aussi de suggérer des mesures de prélèvements quantitatives et qualitatives au sein de la population pour atteindre l’objectif de gestion souhaité. Il reste maintenant à tester son intérêt dans des conditions plus représentatives de la réalité dans notre pays, à savoir sur des territoires où la connaissance de la dynamique des populations est moins détaillée. Cet article relate ainsi la première application de ce modèle dans des conditions plus classiques de gestion, à l’échelle d’un département, le Doubs.

Research paper thumbnail of Linking demographic responses and life history tactics from longitudinal data in mammals

Oikos, 2015

ABSTRACT In stochastic environments, a change in a demographic parameter can influence the popula... more ABSTRACT In stochastic environments, a change in a demographic parameter can influence the population growth rate directly or via a resulting impact on age structure. Stochastic elasticity of the long-run stochastic growth rate λs to a demographic parameter offers a suitable way to measure the overall demographic response because it includes both the direct effect of changing the demographic parameter and its indirect effect through changes in the age structure. From 25 mammalian populations with contrasting life histories, we investigated how pace of life and population growth rate influence the demographic responses (measured as the relative contributions of the direct and indirect components of stochastic elasticity on λs). We found that in short-lived species, the change in population structure resulting from an increase in yearling survival leads to an additional increase in λs, whereas in long-lived species, the same change in population structure leads to a decrease. Short-lived species thus display a boom-bust life history strategy contrary to long-lived species, for which the long lifespan dampens the demographic consequences of changing age structure. Irrespective of the species’ life history strategy, the change in population age structure resulting from an increase in adult survival leads to an additional increase in λs due to an increase of the proportion of mature individuals in the population. On the contrary, a change in population age structure resulting from an increase of reproductive performance leads to a decrease in λs that is due to the increase of the proportion of immature individuals in the population. Our comparative analysis of stochastic elasticity patterns in mammals shows the existence of different demographic responses to changes in age structure between short- and long-lived species, which improves our understanding of population dynamics in variable environments in relation to the species-specific pace of life.

Research paper thumbnail of Mortality rates of wild boar in Europe as a tool for wild boar management

In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is ... more In many parts of Europe wild boar Sus scrofa population increase and dispersal into new areas is accompanied by economic problems. Due to underestimation of population densities and reproduction rates harvest rates seem to be insufficient, especially proportions of shot females might be inadequate. Thus, we calculated mortality rates of several wild boar populations, to show the efficiency of hunting within 13 years from studies conducted in 16 different study areas distributed over 8 European states. For calculating mortality rates the daily probability of survival of radio telemetrically observed wild boar were analysed according to Mayfield (1961) for three age classes (0, 1, ≥2years) and both sexes. Of 872 animals observed by VHF- or GPS-telemetry 228 died during the total observation of 121998 days. The mortality rates of wild boar, especially piglets were low (about 0.5). About three third of all observed animals survived at least until the next period of reproduction. The sex...

Research paper thumbnail of Variations saisonnières du potentiel de dispersion des plantes par les ongulés sauvages

Le potentiel de disperser à longue distance est déterminant pour expliquer les migrations passées... more Le potentiel de disperser à longue distance est déterminant pour expliquer les migrations passées et la distribution actuelle des plantes ainsi que pour prédire leur répartition future, notamment sous la contrainte des changements globaux. Les animaux, le vent, l'eau et les activités humaines sont les principaux vecteurs qui pourraient permettre aux plantes d'accompagner le rythme actuel et futur des changements prédits. Nous nous sommes intéressés aux variations saisonnières du potentiel de dispersion des plantes par endozoochorie, en utilisant comme modèles trois espèces communes d'ongulés sauvages : le chevreuil, le cerf et le sanglier. Tout d’abord, nous avons estimé le temps de rétention interne de graines de 3 plantes proposées à des animaux en semi-captivité. Nous avons quantifié le temps écoulé depuis leur ingestion jusqu'à leur libération dans les fèces en identifiant les graines excrétées pendant 48 heures. Nous avons ensuite quantifié les distances moyenne...

Research paper thumbnail of Seasonal and annual variations in earthworm consumption by wild boar (Sus scrofa scrofa L.)

Wildlife Research, 2003

We investigated the annual and monthly patterns of earthworm consumption by wild boar in the Maur... more We investigated the annual and monthly patterns of earthworm consumption by wild boar in the Maurienne valley (Alps, France). A positive correlation (R 2 = 0.79) was found between weather conditions and patterns of earthworm consumption. A positive correlation was also found between earthworm consumption rates and the occurence of 'worm nights', an easy and direct measure of earthworm availability. W R 0 0 1 1 3 E a r t h wo r m c o n s u mp t i o n b y w i l d b o a r E . B a u b e t e t a l .

Research paper thumbnail of Connaissances sur la biologie du sanglier: Utilisation de l'espace et régime alimentaire

CITATIONS 3 READS 456 4 authors, including: Some of the authors of this publication are also work... more CITATIONS 3 READS 456 4 authors, including: Some of the authors of this publication are also working on these related projects: Parasitism and spatial genetic structure.Example of the Mediteranean Mouflon (Ovis gmelini musimon x Ovis sp.). View project The user has requested enhancement of the downloaded file.

Research paper thumbnail of Influence of harvesting pressure on demographic tactics: implications for wildlife management

Journal of Applied Ecology, 2011

1. Demographic tactics within animal populations are shaped by selective pressures. Exploitation ... more 1. Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. 2. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (k) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. 3. Asymptotic k was 1AE242 in the lightly hunted population and 1AE115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2AE63 and 1AE27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. 4. Compared with expected generation times of similar-sized ungulates (more than 6 years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3AE6 years in the lightly hunted population and only 2AE3 years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. 5. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of management strategies based on context-specific demographic models are useful for selecting interventions for population control. This type of approach allows the assessment of population response to exploitation by considering a range of plausible scenarios, improving the chance of selecting appropriate management actions.