Identifying Endemism Areas: An Example Using Neotropical Lizards

HIBBARD, THOMAS NATHANIEL; DÍAZ-GÓMEZ, JUAN MANUEL; ANDRADE-DÍAZ, MARÍA SOLEDAD

South American Journal of Herpetology

Sociedade Brasileira de Herpetologia

Año: 2017 vol. 12 p. 61 - 75

1808-9798

Areas of endemism are central to biogeography. They are used as study units by analytical biogeographic methods and as a criterion to identify areas for conservation. Liolaemidae is one of the most diverse groups of lizards in terms of species richness and environmental diversity. Over the last decade, the number of new species recorded for the genera Liolaemus and Phymaturus has increased exponentially. Most of them have restricted distributions, low population density, and high extinction risk. These features make this family one of the main environmental components of the ecosystems they inhabit. Furthermore, it has been long recognized that Liolaemidae species, especially within Phymaturus, are endemic, but that recognition was made intuitively and mostly equating endemic with "having a restricted distribution." In this study, we provide methodological confirmation of the high degree of endemism of the species of Liolaemus and Phymaturus, with endemic species defined as those "having congruent distributions." Our goals are to analyze the distribution data of 289 species of Liolaemidae and identify areas of endemism using the software NDM/VNDM. With cells of 0.5° × 0.5°, we identified 27 consensus areas and recovered 118 endemic species (41.11%). These endemic areas presented patterns of repeated taxonomic groups. We also found that some areas of endemism were recovered with different cell sizes, defined by almost the same endemic species. According to the hypothesis of vicariance biogeography, barriers (physical or ecological) fragmented ancestral distributions of taxa. Therefore, the areas of endemism proposed in this study might have been the result of historical events that fragmented the ancestral distribution of the family, giving rise to present day distribution patterns. The identification of biogeographic patterns enables us to understand ecosystems from a historical perspective and generate important information for their conservation. As such, the areas of endemism of a family can be an important and relevant tool to assess priorities for conservation of biodiversity.