Understanding the depredation process in grey wolf (Canis lupus) and its interactions with lethal measures : focus on the French Alpine Arc
After its disappearance from France around the 1950s, the grey wolf (Canis lupus) has returned and is now settled throughout the French Alpine Arc. Its predations on livestock, called depredations, have increased across time since its recolonisation of the region. Depredations mostly concern sheep w...
Main Author: | |
---|---|
Other Authors: | , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
HAL CCSD
2021
|
Subjects: | |
Online Access: | https://theses.hal.science/tel-03558247 https://theses.hal.science/tel-03558247/document https://theses.hal.science/tel-03558247/file/2021_GRENTE_archivage.pdf |
Summary: | After its disappearance from France around the 1950s, the grey wolf (Canis lupus) has returned and is now settled throughout the French Alpine Arc. Its predations on livestock, called depredations, have increased across time since its recolonisation of the region. Depredations mostly concern sheep within the context of pastoralism. The depredation process creates conflicts between wolf conservation and pastoral activities. Besides financial compensations of depredation losses and subsidies for non-lethal protective measures of flocks, France has added another tool of mitigation: lethal removals of wolves. Uncertainty remains about the efficiency of lethal measures to reduce the depredations levels, whether it is in France or elsewhere where these measures are applied. Two opposite assumptions are currently made. The first assumption supports that lethal measures are efficient through population reduction and selection of wolves less likely to depredate. The second assumption supports that lethal measures are counter-productive because of pack disruption which in turn increase the needs of wolves to rely on livestock. The reason for the uncertainty about the effects of lethal measures is the combination of a low number of studies on the subject and a weak scientific inference, thus producing contradictory results. Moreover, most studies have focused on the North American situation. My work consisted in reducing the uncertainty about the effects of lethal measures on the recorded successful depredations on sheep in France. We adopted two approaches. First, we developed an individual-based modelling approach to study the whole dynamic induced by lethal measures on the wolf population structure and on depredations. We integrated biological mechanisms as pack dissolution that were never integrated before. We tested different scenarios of depredation behaviour of wolves. Our model supported that the modelled lethal measures were efficient to reduce depredations through population size reduction 1) when the individual ... |
---|