No abstract

Background: Rhinolophus affinis sensu lato is distributed throughout Southeast Asia. The taxonomic status of forms attributed to the species is unclear due to the limited sample size with incomplete datasets and the taxa have high variation in morphology and echolocation call frequency. The aim of the study was to evaluate the distribution and taxonomic status of the subspecific forms of R. affinis in mainland Southeast Asia using large sample size with multiple datasets, including morphological, acoustic, and genetic data, both to elucidate taxonomic relationships and to test for congruence between these datasets. Results: Three morphological forms were confirmed within the region; two concur with previously recognized taxa, namely R. affinis macrurus and R. affinis superans, and are strongly supported by morphological and genetic data. The third form is morphologically distinct, but its taxonomic status remains unclear. It is probable that this third form represents a distinct taxonomic entity; however, more data are required to confirm this. R. a. macrurus is known from the north of peninsular Thailand, Cambodia, Myanmar, Laos, and Vietnam (Indochinese subregion); R. a. superans is found throughout the Thai-Malay Peninsula (Sundaic subregion); whilst the third form is presently known from east central Myanmar (Shan state) and lower northern Vietnam (Nghe An Province).

Wildlife populations in Southeast Asia are subject to increasing pressure from climate change, habitat loss and human disturbance. Cave-roosting bats are particularly vulnerable to all three factors. Because of the ecological services they provide, it is important to assess specific vulnerabilities to inform their conservation management. We evaluated the reproductive phenology and body condition of Chaerephon plicatus for 14 months in 2015-2016 and quantified guano harvesting at the largest colony in Cambodia in 2011-2016. As in Thailand and Myanmar, two annual breeding cycles were recorded, characterized as continuous bimodal polyoestry, with parturition primarily occurring in April and October. Significant declines occurred in body condition between the late wet season and the late dry season, suggesting that bats experience increasing energetic stress as the dry season progresses. Annual guano harvests increased over the study period but could not be used as a proxy for monitoring population size due to the loss of unknown amounts during the wet season and unquantified movements of bats between C. plicatus colonies in the region. We recommend studies to determine the scale and drivers of such movements and creation of sustainable guano harvesting and population monitoring initiatives to ensure the conservation of C. plicatus colonies in Cambodia.

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.