Amphibian and reptile diversity of Northern Guatemala

Throughout the world an ever-burgeoning human population is putting increasing pressure on natural resources. One result of that pressure is an increasing loss of natural habitat through habitat destruction and change in land use. Currently the effects of change in land use are most strongly felt in tropical regions that also hold the highest levels of biodiversity. Significant gaps in our knowledge exist regarding how changes in land use affect faunal biodiversity and abundance, especially in the case of tropical amphibians and reptiles which can be particularly sensitive to environmental change and are often difficult to detect. Surveys were conducted in Laguna del Tigre National Park (LTNP) in Northern Guatemala with the aim of 1) comparing amphibian and reptile diversity in undisturbed forest and forest adjacent to land converted to agriculture; 2) determining predictors of diversity and finer scale effects of change in land use on assemblage structure; and 3) using the presence of common widespread species to predict hotspots of diversity on a wider regional level. Ninety-two species of amphibians and reptiles were detected from 2013 to 2016 representing 26 families and 5 orders. Eighteen percent of amphibian species and 50% of reptiles were found to be of regional conservation concern, considerably higher than when those species were considered at current national and global levels.

Diversity of amphibians and reptiles was significantly lower in forest adjacent to agriculture than in undisturbed habitat. Assemblage structure was significantly altered in disturbed habitat, with a few common species dominating other species that were present. Tolerance of dry environmental conditions and specialised diet were identified as traits that allowed for successful colonisation of disturbed forest. The presence of species with widespread distributions revealed more information about overall diversity of a location than did the presence of rare species. Moreover, the presence of species common to multiple locations in the Mayan Biosphere Reserve (MBR) could be used to predict levels of diversity at under-sampled locations. Change in land use and resulting disturbance of adjacent forest could have a more significant impact on amphibians and reptiles than realized. Conservation policy for amphibians and reptiles within the MBR should take their local conservation status into consideration in addition to national and global assessments.