Living among thorns: herpetofaunal community (Anura and Squamata) associated to the rupicolous bromeliad Encholirium spectabile (Pitcairnioideae) in the Brazilian semi-arid Caatinga

Bromeliads are important habitats for reptiles and amphibians, and are constantly used as shelter, refuge, foraging or thermoregulation sites due to their foliar architecture, which allows for constant maintenance of humidity and temperature. This study aimed to identify the herpetofauna inhabiting the non-phytotelmata rupicolous bromeliad Encholirium spectabile Mart. ex Schult. & Schult.f. and to analyze the microhabitat usage of these bromeliads by different species in the Caatinga of northeastern Brazil. From January 2011 to August 2012, we collected data by active search throughout three paralel transects in a rock outcrop in the municipality of Santa Maria, state of Rio Grande do Norte. We recorded four species of anuran amphibians, six lizards, and seven snakes in the bromeliads. The average air temperature was lower and air humidity higher inside than outside the bromeliads, and bromeliads at the rock outcrop borders had lower temperatures and higher humidity than those at the center. We found a significant difference in the distribution of individuals throughout the rock outcrop, with most specimens found at the borders. We also found significant differences regarding the use of each microhabitat by the taxonomic groups, with lizards and snakes using green leaves and dry leaves evenly, along with fewer records in inflorescence stems, and anurans mainly using green leaves, with few records on dry leaves, and no records in the inflorescence stems. This study highlights rupicolous bromeliads as key elements in the conservation and maintenance of amphibians and reptiles in the rock outcrops of Brazilian semi-arid Caatinga.