Cambios en el paisaje y prioridades de conservación: una perspectiva herpetofaunística mexicana a escalas local y regional

摘要

Few studies have demonstrated historical human impact on biodiversity at local and regional scales, largely due to lack of baseline information and long term monitoring for most taxa. In 1958 and 1959 researchers from the Museum of Vertebrate Zoology (MVZ) visited the Mexican state of Aguascalientes and increased its documented amphibian andreptile fauna from 21 to 30 species. Using MVZ collections, field notes, and landscape photographs taken during that expedition, we resurveyed those same localities in 2004 to document herpetofaunal changes coincident with greatly increased human activities. Despite its small area, Aguascalientes encompasses several biogeographic regions and the threat of local extinction at species' distributional limits has broader implications for regional biotas. New discoveries raise to 71 the number of species known for that state, but our comparisons suggest a gloomy future for amphibians and reptiles in Aguascalientes. Paradoxically, human impact is managed primarily at state and municipal levels, often devoid of locally relevant context. Our findings illustrate the conservation value of intensive small-scale studies, focused on the natural history of particular species and localities, as complements to large-scale biodiversity assessments on country wide and continental scales.