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...
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Other Authors: | , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
HAL CCSD
2021
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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 pastoral context. The depredation process creates conflicts between wolf conservation and pastoral activities. Besides financial compensations of depredation losses and subsidies for the non-lethal protection 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 they are applied. Two opposite assumptions are usually made. The first assumption supports that the lethal measures are efficient through population reduction and selection of wolves less likely to depredate. The second assumption supports that the lethal measures are counter-productive because they disrupt pack stability and in turn increase the needs for wolves to rely on livestock.The reason for this uncertainty about the effects of lethal measure is the combination of a low number of studies on the subject, weak scientific inference, resulting in 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 the 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 probability of ... |
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