Geographical Variation ofRhinolophus affinis(Chiroptera: Rhinolophidae) in the Sundaic Subregion of Southeast Asia, including the Malay Peninsula, Borneo and Sumatra

Abstract

Rhinolophus affinis sensu lato is a widespread bat species in South and Southeast Asia which shows considerable geographical variation in its morphology, echolocation call frequencies and genetics. The taxonomic status of the taxon in the Sundaic subregion remains uncertain however as the limited studies to date have been largely based on morphology. The aim of the present study was to determine the taxonomic status of subspecific forms recognized in the subregion and to evaluate phylogeographic distinctiveness between those occurring in Borneo and the Malay Peninsula using genetic, morphological and acoustic datasets. Two forms were confirmed: R. a. nesites from Borneo and R. a. superans from the peninsula. The previous recognition of a population from southernmost Sumatra as R. a. superans was not supported, however, as this form is likely R. a. affinis. Genetic divergence between these three forms is rather deep and is estimated to have occurred during the arid climatic period of the Pleistocene when suitable habitats were reduced to isolated pockets. Our results support the phylogeographic distinctiveness hypothesis as R. affinis sensu lato shows discrete affinities between Borneo and the Malay Peninsula. Discovery of new forms of R. affinis is likely with greater sampling effort throughout the region. Our study also demonstrates the importance of employing multiple datasets in taxonomic evaluations, as the use of morphological and/or acoustic datasets alone could lead to erroneous conclusions.

Bats (Mammalia: Chiroptera) of the southeastern Truong Son Mountains, Quang Ngai Province, Vietnam

“…In R. affinis, the coefficient of variation was <1% for FMAXE of 216 calls from 18 bats recorded at our study area in Quang Ngai, whereas calls recorded previously in Vietnam, China, Lao PDR, Myanmar, Malaysia, Borneo and Sumatra (but not central Java) were generally outside of the range of minimum-maximum values from our study area (Table 5; Ith et al 2015). In our study area the higher FMAXE of echolocation calls of R. affinis (sensu lato) did not follow the geographic trend suggested by Ith et al (2016) of lower frequencies north of the Kangar-Pattani Line across the Thai-Malay Peninsula. Discrepancies also are found between calls of R. pusillus in the present study and those from some locations in China, Thailand, Lao PDR, and Vietnam (Table 5).…”

Integrated approaches to identifying cryptic bat species in areas of high endemism: the case ofRhinolophus andamanensisin the Andaman Islands

“…The bacular morphology of R. affinis studied in southeast Asia showed a divergent pattern between the Indochinese and the Sundaic subregions. The Indochinese bacula were smaller, had a curved shaft and a bulbous base, while the Sundaic population showed the presence of a larger bacula with a straighter shaft and a broad base [30].…”

“…Specimen data on different subspecies of Rhinolophus affinis was sourced from the work of Ith and colleagues [30] for comparison with the taxon andamanensis . The bats were classified into five groups: Java, Borneo, North Malaysia, and South Malaysia [30], and Andaman.…”

“…Specimen data on different subspecies of Rhinolophus affinis was sourced from the work of Ith and colleagues [30] for comparison with the taxon andamanensis . The bats were classified into five groups: Java, Borneo, North Malaysia, and South Malaysia [30], and Andaman. A priori multicollinearity tests were conducted on the morphological variables in R [31], and a principal component analysis (PCA) was done on all the morphological characters in R [31].…”

Environmental influences on acoustic divergence inRhinolophusbats of the Western Ghats-Sri Lanka region

“…Analyses were done separately for the four species to account for their phylogeographic distinctiveness (Ith et al, 2016). We first assessed variation in RF along latitudinal climatic gradients and across biogeographic zones of the WGSL.…”