Big family, warm home, and lots of friends: Pteronotus large

Roosts are essential for the survival of most animals. Due to homothermic requirements, mammals are particularly dependent on roost quality and availability. Bats select their roosts in a species-specific way, likely related to species´ different physiological and adaptive needs. Unlike species whose individuals roost solitarily, roost selection is critical for bats forming large colonies due to the requirements for maintaining thousands of individuals in a single shelter. This is the case of Pteronotus (Mormoopidae), whose colonies reach hundreds of thousands of bats. Using captures, bioacoustics, and automated censuses, we evaluated how cave size, ceiling characteristics, environmental stability, temperature, and humidity influence the formation of exceptionally large colonies, species richness and composition in caves in north-eastern Brazil. We expected that colonies would be positively related to cave size and stability and internal cave selection would be species-specific, but lar...,
1.1  Study area

We sampled eleven caves distributed in the states of Sergipe (2 caves), Pernambuco (3), Rio Grande do Norte (3), and Ceará (3), in the Northeast Region of Brazil (Figure 1). The caves differed in formation, having limestone or sandstone origin (Table 1).
The caves of Sergipe are located in the ecotone between the Atlantic Forest and Caatinga biomes, where the Tropical Megathermal climate predominates, with dry season during summer and temperatures varying between 23 and 27°C. Average annual rainfall in Sergipe ranges from 1,000 and 1,400 mm, usually concentrated from April to August (Alvares et al., 2013; Aragão et al., 2013). The other caves (n = 9) are located in the Brazilian semi-arid region, which is part of the Caatinga biome characterized as a seasonally dry tropical forest (Silva et al., 2017). The region has a hot semi-arid climate, with temperatures ranging between 25 and 30°C and average annual rainfall varying spatiotemporally between 600 and 1,200 mm usual..., We used presence and absence data from the bat species to analyze, using mvabund package, the relationship with the caves characteristics. The data is organized in a spreadsheet containing in each column the values for the caves features, followed by the data of presence/absence of each species. The file “mvabund” was used as an input in R on the script described below.