The distribution of two buthid species in a fragment of Brazilian Atlantic forest

Gabriela Cavalcanti Silva de Gusmão Santos and co-workers recently published a study on the effect of rainfall on the patterns in the spatial distributions and population densities of the two species Tityus pusillus Pocock 1893 and Ananteris mauryi Lourenço 1982 (both Buthidae). The two species are living sympatrically in a fragment of Atlantic Forest in Brazil.

The results showed evidence that environmental factors at a microhabitat scale and species interactions may play an important role in the distribution, but not the density of the two leaf litter-dwelling scorpions. See article for further details.

Abstract:
Knowledge of the patterns in the spatial distribution of species provides valuable information about the factors (resources and environment) that regulate the use of space by animals. Typically, the distribution of litter-dwelling scorpions in Atlantic forests is correlated with the structure of their microhabitats, although to better understand their natural history more studies on the patterns in their use of space are required. Therefore, we investigated the effect of rainfall on the patterns in the spatial distributions and population densities of two sympatric species of scorpion, Tityus (Archaeotityus) pusillus Pocock 1893 and Ananteris mauryi Lourenço 1982 in a fragment of Atlantic Forest in Brazil. The study was carried out during the dry (September) and rainy (June) months. We collected 501 individuals (268 T. (A.) pusillus and 233 A. mauryi) by actively searching at night using UV lanterns. We found that the spatial distribution and population density of T. (A.) pusillus, but not A. mauryi, were signifi cantly affected by rainfall, with T. (A.) pusillus individuals showing a clumped pattern during the rainy month and random distribution in the dry month. We also found a different response in the population densities of the two species, with T. (A.) pusillus but not A. mauryi being affected by rainfall. Our results indicate that, although co-habiting in leaf litter, these species respond differently to rainfall, which affects their spatial distribution and abundance in this habitat.

Reference:
Santos GCSdG, Dionisio-da-Silva W, Souza-Alves JP, Albuquerque CMRd, Lira AFDA. Random or clumped: How litter dwelling scorpions are distributed in a fragment of Brazilian Atlantic forest. European Journal of Entomology. 2018;115:445–9.

Thanks to Andre Lira for sending me their article!