Comparative phylogeography of bamboo bats of the genus Tylonycteris (Chiroptera, Vespertilionidae) in Southeast Asia

Vuong Tan Tu,Vu Dinh Thong,Alexandre Hassanin,Nguyen Truong Son,Neil M. Furey,Céline Bonillo,Manuel Ruedi,Gábor Csorba

doi:10.5852/ejt.2017.274

Abstract

In Southeast Asia, bats of the genus Tylonycteris Peters, 1872 have traditionally been classified into two wide-ranging species, T. pachypus (Temminck, 1840) and T. robustula Thomas, 1915. Our comparative phylogeographic analyses based on two mitochondrial and seven nuclear genes, combined with our multivariate morphological analyses, show that these species actually represent cryptic species complexes that share a similar biogeographic history in three major regions, i.e., Sundaland, southern Indochina, and northern Indochina. Our molecular dating estimates suggest that Pleistocene climatic oscillations and sea level changes have repeatedly isolated ancestral populations of Tylonycteris spp. in distant bamboo forest refugia. The analyses indicate, however, that populations of the T. pachypus complex were less affected by forest fragmentation in mainland Southeast Asia than those of the T. robustula complex. Accordingly, we propose several taxonomic changes within the genus Tylonycteris: the species T. fulvida and T. malayana are revalidated, and a new species, T. tonkinensis Tu, Csorba, Ruedi & Hassanin sp. nov., endemic to northern Indochina, is described.

Highlights

Bamboo bats of the genus Tylonycteris Peters, 1872 (Chiroptera, Vespertilionidae) are small-sized bats characterized by a dorsoventrally flattened skull and well-developed, fleshy pads at the base of the thumb and on the sole of the foot (Tate 1942)
As noted by Huang et al (2014), one specimen labelled as T. robustula in GenBank appears within the clade containing all sequences of T. pachypus
Results derived from the analysis of cytochrome b (Cytb) sequences The Bayesian analysis of the newly generated Cytb sequences (n = 19) and those of Tylonycteris downloaded from GenBank (n = 4) produced a topology (Fig. 2) similar to those obtained with the COI gene tree, with two exceptions: (1) T. robustula is paraphyletic because one specimen collected

Summary

Introduction

Bamboo bats of the genus Tylonycteris Peters, 1872 (Chiroptera, Vespertilionidae) are small-sized bats (weight: 3–10 g; forearm length: 22–32 mm) characterized by a dorsoventrally flattened skull and well-developed, fleshy pads at the base of the thumb and on the sole of the foot (Tate 1942). Whereas T. pygmaea is considered to be endemic to Yunnan Province in southern China, the two other species have much more extensive geographic ranges that greatly overlap in Southeast Asia (Fig. 1). The range of T. pachypus is even more extended in the north and west, with apparently two isolated populations recorded in the Chinese provinces of Sichuan and Chongqing, and in southern India around the Western Ghats (Fig. 1) (Bates et al 2008a, 2008b)

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