Unveiling the Hidden Bat Diversity of a Neotropical Montane Forest

Abstract

Mountain environments, characterized by high levels of endemism, are at risk of experiencing significant biodiversity loss due to current trends in global warming. While many acknowledge their importance and vulnerability, these ecosystems still remain poorly studied, particularly for taxa that are difficult to sample such as bats. Aiming to estimate the amount of cryptic diversity among bats of a Neotropical montane cloud forest in Talamanca Range-south-east Central America-, we performed a 15-night sampling campaign, which resulted in 90 captured bats belonging to 8 species. We sequenced their mitochondrial cytochrome c oxidase subunit I (COI) and screened their inter- and intraspecific genetic variation. Phylogenetic relations with conspecifics and closely related species from other geographic regions were established using Maximum Likelihood and Bayesian inference methods, as well as median-joining haplotype networks. Mitochondrial lineages highly divergent from hitherto characterized populations (> 9% COI dissimilarity) were found in Myotis oxyotus and Hylonycteris underwoodi. Sturnira burtonlimi and M. keaysi also showed distinct mitochondrial structure with sibling species and/or populations. These results suggest that mountains in the region hold a high degree of endemicity potential that has previously been ignored in bats. They also warn of the high extinction risk montane bats may be facing due to climatic change, particularly in isolated mountain systems like Talamanca Range.

Fig 1. Map showing the location of Valle del Silencio in Parque Internacional La Amistad.

Inset shows the enlarged area (red shade) within its geographic context. Data used to generate this map were obtained from Natural Earth (public domain, http://www.naturalearthdata.com/).

Fig 2

Species richness estimates for a rarefied and extrapolated sample with respect to sample size (a), and estimated species richness according to sample coverage (b). Shaded areas represent 95% confidence intervals, and dashed lines represent extrapolated data. Reprinted from the online version of the software iNEXT (https://chao.shinyapps.io/iNEXT/) under a CC BY license, with permission from Anne Chao, original copyright 2013.

Fig 3

(A) Consensus Bayesian and Maximum Likelihood (ML) radial phylogenetic tree of mitochondrial COI barcode sequences (657 bp) of Myotis species. Node colors indicate average values of posterior probabilities (Bayesian) and the bootstrap percentages (ML). Numbers indicate the number of individuals in each tip, which cannot be appreciated due to scale. Note that the branch-length of the output taxon Eptesicus furinalis has been cut for scale reasons. A more detailed tree is available as supplementary material. (B) Median-joining network of Myotis keaysi haplotypes. Yellow dots indicate actual haplotypes, while red dots missing intermediate haplotypes. Dot size indicates the number of individuals sharing a certain haplotype. The color of connecting lines indicates genetic distance in number of nucleotide polymorphisms. Note that the spatial resolution of the haplotype locations is approximate (country level).

Fig 4

(A) Consensus Bayesian and Maximum Likelihood (ML) radial phylogenetic tree of mitochondrial COI barcode sequences (657 bp) of phyllostomid species. Node colors indicate average values of posterior probabilities (Bayesian) and the bootstrap percentages (ML). Numbers indicate the number of individuals in each tip, which cannot be appreciated due to scale. Note that the branch-length of the output taxon Artibeus jamaicensis has been cut for scale reasons. A more detailed tree is available as supplementary material. (B) Median-joining network of Sturnira burtonlimi and Sturnira ludovici sensu lato haplotypes. Yellow dots indicate actual haplotypes, while red dots missing intermediate haplotypes. Dot size indicates the number of individuals sharing a certain haplotype. The color of connecting lines indicates genetic distance in number of nucleotide polymorphisms. Note that the spatial resolution of the haplotype locations is approximate (country level).