Résumé
Habitat quality should be usefully defined in a demographic perspective. Survival and fecundity rates are sufficient to allow population persistence in a high-quality habitat but not in a low-quality habitat. The Mediterranean pine vole (Microtus duodecimcostatus) occurs in apple orchards in southern France, but its populations in this habitat are often driven to extinction by chemical control. However, recolonization occurs promptly when control ceases. We tested the hypothesis that meadows surrounding the orchards are high-quality habitats (sources) for the Mediterranean pine vole. We livetrapped four populations, three in apple orchards and one in a meadow. Survival rates were estimated using probabilistic open-population models. Our analysis led us to conclude that meadows are low-quality habitats, particularly since no juveniles survived in this habitat during the main part of the study. Recolonization of chemically controlled patches is probably allowed by asynchronous control among orchards. We further discuss the usefulness of probabilistic open-population models for the investigation of variations in survival rates both within and between populations.