The Dominance of Introduced Plant Species in the Diets of Migratory Galapagos Tortoises Increases with Elevation on a Human-Occupied Island

摘要: ABSTRACT The distribution of resources and food selection are fundamental to the ecology, life history, physiology, population dynamics, con-servation animals. Introduced plants changing foraging dynamics herbivores in many ecosystems often with unknown conse-quences. Galapagos tortoises, like herbivores, undertake migrations along elevation gradients driven by variability vegetationproductivity which take them into upland areas dominated introduced plants. We sought characterize diet composition two spe-cies focussing on how role forage species changes over space implications for tortoiseconservation. quantified tortoises using GPS telemetry. Along gradient, we quantifiedthe abundance native plant species, estimated recording foods consumed andassessed tortoise physical condition from body weights blood parameter values. Tortoises ranged between 0 429 m elevationover they at least 64 26 families, 44 percent were species. Cover introducedspecies proportion diets increased elevation. positively selectedfor all elevations. Tortoise was either consistent or biologically pro-ductive season Galapagos. Santa Cruz generalist that have adapted their feeding behavior consume manyintroduced has likely made a positive contribution nutrition. Some transformed habitats contain anabundance compatible conservation.Abstract Spanish is available online version this article.