Distributional Patterns and Ecological Determinants of Bat Occurrence Inside Caves: A Broad Scale Meta-Analysis

Hernani de Oliveira,Raphael Dias,Monik Oprea

doi:10.3390/d10030049

Hernani de Oliveira, Raphael Dias + Show 1 more

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https://doi.org/10.3390/d10030049

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Abstract

Caves are important bat roosts worldwide that are used as shelters, maternity roosts, and to help in thermoregulation. Bat abundances, species richness, and association patterns inside caves can be affected by large-scale environmental variation. However, few studies have analyzed the effect of latitudinal and altitudinal variations on these patterns. Here, we conducted a large literature review about cave occupation by bats in Brazil. We investigated the effects of elevation and latitude on bat richness and abundance, the effect of Brazilian biomes on bats’ abundance and richness, the dependence between feeding guilds and biomes, and the effects of the number of studies conducted and the number of caves per region on bat species richness. A total of 72 studies with 9666 bats from 72 species were registered in 247 caves. We found that species richness increases toward the equator and reaches its limit at low and intermediate altitudes. Reported richness was influenced by the number of studies conducted in each region. Both latitude and elevation explained the variation in abundance and were significantly affected by biome type. The latitudinal and elevational gradient for species’ richness and abundance may be explained by the creation of stable thermal conditions in roosts at high elevations and low latitudes.

Highlights

Understanding why diversity varies across the globe has attracted the interest of ecologists for centuries [1,2]
The mean altitude where diversity reaches its peak has been shown to vary across taxonomic groups, being higher in non-flying mammals and intermediate in bats [18], but at least 50% of the studies conducted in high
Ecological gradients of species richness and abundance are well documented for many taxa [2], but little is known about how much cave-dwelling bats follow these patterns

Summary

Introduction

Understanding why diversity varies across the globe has attracted the interest of ecologists for centuries [1,2]. Different hypotheses have been proposed to explain the variation in the number of species, community structure, and life history traits on a global scale [3]. Variation in species’ richness and abundance has been shown to be affected by both broad and local-scale determinants [3,4,5]. An elevational trend has been reported, with areas of higher altitude presenting greater species richness and endemism for different taxa [16,17]. The mean altitude where diversity reaches its peak has been shown to vary across taxonomic groups, being higher in non-flying mammals and intermediate in bats [18], but at least 50% of the studies conducted in high

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