Réseaux de surveillance et d'alerte

Numerical response of predators to large variations of grassland vole abundance and long‐term community changes

Abstract Voles can reach high densities with multiannual population fluctuations of large amplitude, and they are at the base of predator communities in Northern Eurasia and Northern America. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues. Here, a 20‐year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts. Our results show how the predator community responded to prey variations of large amplitude and how it reorganized with the increase in a dominant predator…

Campagraphe

Les moyennes montagnes du Jura et de l'Auvergne sont régulièrement envahies par un rongeur prairial, le campagnol terrestre. La connectivité des surfaces de prairies étant un des facteurs favorisant cette propagation, le projet vise à utiliser une modélisation du réseau prairial fondée sur les graphes paysagers comme un guide pour expérimenter des actions de lutte sur le terrain. A partir de ces modèles, il s'agira tout d'abord de délimiter des entités fonctionnelles reposant sur la notion de synchronie, pour proposer des zonages adaptés au suivi des populations, tel qu'il est effectué par les partenaires professionnels impliqués dans la lutte contre les pullulations. Les graphes paysagers …

Numerical response of predators to large variations of grassland vole abundance, long-term community change and prey switches

AbstractVoles can reach high densities with multi-annual population fluctuations of large amplitude, and they are at the base of large and rich communities of predators in temperate and arctic food webs. This status places them at the heart of management conflicts wherein crop protection and health concerns are often raised against conservation issues. Here, a 20-year survey describes the effects of large variations in grassland vole populations on the densities and the daily theoretical food intakes (TFI) of vole predators based on roadside counts. Our results show how the predator community responds to prey variations of large amplitude and how it reorganized with the increase in a domina…

Trophic transfer of pesticides: The fine line between predator–prey regulation and pesticide–pest regulation

International audience; Understanding pesticide impacts on populations of target/non-target species and communities is a challenge to applied ecology. When predators that otherwise regulate pest densities ingest prey contaminated with pesticides, this can suppress predator populations by secondary poisoning. It is, however, unknown how species relationships and protocols of treatments (e.g. anticoagulant rodenticide [AR]) interact to affect pest regulation.To tackle this issue, we modelled a heuristic non-spatialized system including montane water voles, specialist vole predators (stoats, weasels) and a generalist predator (red fox) which consumes voles, mustelids and other prey. By carryin…

Les graphes paysagers pour la modélisation et la gestion des pullulations de campagnols terrestres.

International audience; Les prairies d’Auvergne et de Franche-Comté sont régulièrement envahies par un rongeur, le campagnol terrestre. Le projet CAMPAGRAPHE vise à fournir un appui pour la mise en place d’un dispositif agro-écologique limitant sa diffusion grâce à une modélisation des réseaux de prairies.Le graphe obtenu permet de localiser des actions de terrain et orienter le suivi des populations.