Dynamics, regulation and viability of restored populations : the case of the Cinereous vulture (Aegypius monachus) in France

Les réintroductions sont des opérations de conservation visant la restauration des populations d’espèces menacées. L’analyse des facteurs influençant le succès ou les échecs des programmes de réintroduction est cruciale pour comprendre les processus d’établissement d’une nouvelle population; identifier les potentiels facteurs qui pourraient limiter la croissance de cette population; et mesurer si l’objectif majeur de restaurer une population viable sur le long terme est atteint. Dans cette thèse, j’ai utilisé des approches démographiques et spatiales, incluant des estimations de survies et de mouvements par modèles CMR multi évènement, pour améliorer la compréhension de la dynamique spatio-temporelle des trois populations de vautours moines réintroduites en France (une dans les Grands-Causses et deux dans les Préalpes) et discuter du succès de ces programmes de réintroduction à différentes échelles populationnelles et temporelles. Nous avons utilisé les estimations démographiques obtenues et les proxys de capacités limites du milieu à chaque niveau populationnel, pour élaborer des modèles de dynamique et de viabilité des populations. Ceux-ci nous ont permis de quantifier les tendances/les taux de croissance de chaque population et de la (méta)population française dans son ensemble, ainsi que d’étudier leur probabilité d’extinction sur le long terme.Reintroductions are conservation programs aimed at restoring populations of threatened species. Analysis of the factors influencing the success or failure of reintroduction programs is crucial to understand the processes involved in establishing a new population; to identify potential factors that could limit the growth of this population; and to measure whether the major objective of restoring a viable population over the long term has been achieved. In this thesis, I used demographic and spatial approaches, including multievent CMR modelling of survival and movement, to improve the understanding of the spatio-temporal dynamics of the three populations of reintroduced cinereous vultures in France (one in the Grands-Causses and two in the Prealps) and to discuss the success of these reintroduction programs at different population and temporal scales. We used the demographic parameters obtained and proxies of carrying capacities at each population level to develop population dynamic models and population viability analyses. These enabled us to quantify the growth rates of each population and of the French (meta)population as a whole, as well as to study their probability of extinction Reintroductions are conservation programs aimed at restoring populations of threatened species. Analysis of the factors influencing the success or failure of reintroduction programs is crucial to understand the processes involved in establishing a new population; to identify potential factors that could limit the growth of this population; and to measure whether the major objective of restoring a viable population over the long term has been achieved. In this thesis, I used demographic and spatial approaches, including multievent CMR modelling of survival and movement, to improve the understanding of the spatio-temporal dynamics of the three populations of reintroduced cinereous vultures in France (one in the Grands-Causses and two in the Prealps) and to discuss the success of these reintroduction programs at different population and temporal scales. We used the demographic parameters obtained and proxies of carrying capacities at each population level to develop population dynamic models and population viability analyses. These enabled us to quantify the growth rates of each population and of the French (meta)population as a whole, as well as to study their probability of extinction in the long term

Dynamique, régulation et viabilité des populations restaurées : le cas du Vautour moine (Aegypius monachus) en France

Reintroductions are conservation programs aimed at restoring populations of threatened species. Analysis of the factors influencing the success or failure of reintroduction programs is crucial to understand the processes involved in establishing a new population; to identify potential factors that could limit the growth of this population; and to measure whether the major objective of restoring a viable population over the long term has been achieved. In this thesis, I used demographic and spatial approaches, including multievent CMR modelling of survival and movement, to improve the understanding of the spatio-temporal dynamics of the three populations of reintroduced cinereous vultures in France (one in the Grands-Causses and two in the Prealps) and to discuss the success of these reintroduction programs at different population and temporal scales. We used the demographic parameters obtained and proxies of carrying capacities at each population level to develop population dynamic models and population viability analyses. These enabled us to quantify the growth rates of each population and of the French (meta)population as a whole, as well as to study their probability of extinction Reintroductions are conservation programs aimed at restoring populations of threatened species. Analysis of the factors influencing the success or failure of reintroduction programs is crucial to understand the processes involved in establishing a new population; to identify potential factors that could limit the growth of this population; and to measure whether the major objective of restoring a viable population over the long term has been achieved. In this thesis, I used demographic and spatial approaches, including multievent CMR modelling of survival and movement, to improve the understanding of the spatio-temporal dynamics of the three populations of reintroduced cinereous vultures in France (one in the Grands-Causses and two in the Prealps) and to discuss the success of these reintroduction programs at different population and temporal scales. We used the demographic parameters obtained and proxies of carrying capacities at each population level to develop population dynamic models and population viability analyses. These enabled us to quantify the growth rates of each population and of the French (meta)population as a whole, as well as to study their probability of extinction in the long term.Les réintroductions sont des opérations de conservation visant la restauration des populations d’espèces menacées. L’analyse des facteurs influençant le succès ou les échecs des programmes de réintroduction est cruciale pour comprendre les processus d’établissement d’une nouvelle population; identifier les potentiels facteurs qui pourraient limiter la croissance de cette population; et mesurer si l’objectif majeur de restaurer une population viable sur le long terme est atteint. Dans cette thèse, j’ai utilisé des approches démographiques et spatiales, incluant des estimations de survies et de mouvements par modèles CMR multi évènement, pour améliorer la compréhension de la dynamique spatio-temporelle des trois populations de vautours moines réintroduites en France (une dans les Grands-Causses et deux dans les Préalpes) et discuter du succès de ces programmes de réintroduction à différentes échelles populationnelles et temporelles. Nous avons utilisé les estimations démographiques obtenues et les proxys de capacités limites du milieu à chaque niveau populationnel, pour élaborer des modèles de dynamique et de viabilité des populations. Ceux-ci nous ont permis de quantifier les tendances/les taux de croissance de chaque population et de la (méta)population française dans son ensemble, ainsi que d’étudier leur probabilité d’extinction sur le long terme

High long-term survival and asymmetric movements in a reintroduced metapopulation of Cinereous vultures

International audiencePost-release mortality and movements are top proximate factors of translocation failure. Yet, survival and movement reflect different demographic and behavioral processes and may therefore have contrasted responses to management, although they are often very difficult to disentangle in animal populations. To provide guidance in animal translocations, we discriminated the respective roles of survival and movement in the long-term dynamic of a translocated metapopulation of cinereous vultures (Aegypius monachus) in France using multi-event capture-recapture analyses of reintroduced (n=119) and wild-born individuals (n=163) observations. Annual apparent survival rates were high and structured in age (>0.8 for young and >0.9 for adults) and did not differ between individuals origin (wild-born or released), release methods (aviary or hacking) nor between regions (Alps and Causses), except for those released in the Alps experiencing a reduced survival for one year after release. In contrast, age structure movements differed between populations and origin status. Wild-born young from the Causses were more erratic than those from the Alps and older individuals, whereas vultures reintroduced in the Causses demonstrated restricted movements during their first year after release. Despite such asymmetric movements, we overall highlight a strong tropism of individuals whatever the region and their origin. Since movement and survival were respectively higher and lower in young compared to adults, we recommend to first release adults in the primary stage of metapopulation translocations for increasing the establishment success at the release site. Further releasing young and securing successful breeding into the wild would increase demographic growth and between population connections