Publications des scientifiques de l'IRD

Ruffino L., Russell J. C., Pisanu B., Caut S., Vidal Eric. (2011). Low individual-level dietary plasticity in an island-invasive generalist forager. Population Ecology, 53 (4), p. 535-548. ISSN 1438-3896.

Titre du document
Low individual-level dietary plasticity in an island-invasive generalist forager
Année de publication
2011
Type de document
Article référencé dans le Web of Science WOS:000293544400003
Auteurs
Ruffino L., Russell J. C., Pisanu B., Caut S., Vidal Eric
Source
Population Ecology, 2011, 53 (4), p. 535-548 ISSN 1438-3896
The ability of invasive mammals to adjust their diet in response to new or variable resources is often proposed to explain their invasion success on islands with differing environmental conditions, especially islands with strong spatiotemporal changes in the nature and abundance of their resources. In this study, we investigated how habitat heterogeneity and seasonal fluctuation in resource quality affect dietary breadth and plasticity in an island-invasive rodent, the black rat Rattus rattus, on a small Mediterranean island. We tested for dietary plasticity of rats at both the individual and population levels by using traditional dietary and stable isotope analyses at successively increasing time scales, coupled with a long-term study of individual rats in three habitats of close proximity. Dietary and movement analyses both indicated that R. rattus is able to exploit a wide range of resources and habitats. However, dietary plasticity and habitat breadth were far narrower at the individual level. Results revealed that rats exclusively used resources found in their local habitat, and very few individuals moved among adjacent habitats in pursuit of higher-quality resources, despite those resources being abundant in their immediate environment. This counterintuitive finding suggests that intraspecific interactions must restrict rat mobility. Our results suggest that even on small islands, accessibility of patchy and high-quality resources to individuals from the entire population is not systematic. This result has important implications when quantifying invasive rodent impacts on patchily distributed species, especially when studies use indirect methods such as dietary analyses as a substitute for direct observations of predatory behavior.
Plan de classement
Sciences du monde animal [080]
Localisation
Fonds IRD [F B010053745]
Identifiant IRD
fdi:010053745
Contact