Diversidade e uso do microhábitat de lagartos em uma região do domínio das caatingas, Nordeste do Brasil

Abstract

Of all Squamata diversity, lizards represent more than half of described species in present. These animals serve as models for ecological and evolutionary studies, which makes them target of interest in scientific research in whole world. Caatinga is a major biome in Northeast of Brazil, occupying about 6.83% of the national territory and extending for several states of this region. It is a unique biome, and despite being located on a semi-arid climate, has a great variety of landscapes, biological richness and endemism. Reptile’s studies of diversity, composition and ecology in Caatinga are relatively recent, these research are extremely important and valuable to semiarid. But this information is punctual and does not represent Northeast biodiversity, requiring more effort in different localities, especially in rainforest areas of biome. This study aims to investigate lizard’s abundance, richness, diversity, spatial distribution and width/niche overlap in the Environmental Protection Area of Araripe. To achieve this goal, we sampled three different vegetation types (shrubby Caatinga, Cerradão and secondary Forest) APA of Chapada Araripe. The data collections were made monthly by active and passive collecting, during the twelve-month period (August/2011 to July/2012). The active collection was made one day for each area per month and lasting for six hours a day, three hours in the morning (8h to 11h), and three hours at night (18 to 21h). The passive collections were made using 60 pitfall traps with drift-fences, these were organized into twelve lines with five buckets at 5m of distance between them, and the lines were equally distributed at three vegetation types. Buckets were open for five days during each month. As a result, we found 20 lizard species belonging to 12 families. Richness and abundance varied among the three areas sampled. Caatinga had the highest number of species (n = 14) and Cerradão had de highest abundance (n = 99). Ameiva ameiva was the most abundant lizard from caatinga, while in Cerradão was Colobosaura modesta and for secondary forest was Norops brasiliensis. Lizards presents significant difference respect to the seasons (wet and dry), in the dry season the lizards were more abundant. Analyses based on null models indicate no significant values on the overlap of microhabitat use, showing that competition for space is not regulating this community structure, being regulated by other factors.