102.

Chocolate Pipistrelle

Hypsugo affinis

French: Vespére chocolat / German: Hochland-Zwergfledermaus / Spanish: Hypsugo chocolatero

Other common names: Grizzled Pipistrelle, Highland Pipistrelle

Taxonomy. Vesperugo (Pipistrellus) affinis Dobson, 1871,

Bhamo, 1372 m, Kachin State, north-eastern Myanmar.

This species, Hypsugo petersi and H. mordax were previously placed in Pipustrellus, where the first two were treated in the “ affinis group” (with some other Asian species) by G. H. H. Tate in 1942, and by K. F. Koopman in 1994. In 1987, based mainly on bacular characters of affinis and petersi ( mordax was not included in the study), J. E. Hill and D. L. Harrison redefined the affinis group, limiting it to these three species ( mordax tentatively), which they placed in the subgenus Falsistrellus of Pipustrellus, alongside the Australian forms tasmaniensis and mackenziei (the tasmaniensis group). G. B. Corbet and Hill followed this arrangement in 1992, whereas in 2005 N. B. Simmons recognized Falsistrellus as a valid genus, with the same five species. The phylogenetic studies of L.. R. Heaney and colleagues in 2012 and M. Ruedi and colleagues in 2017, revealed a close relationship of petersi to Hypsugo . On the basis of sequence data of mitochondrial and nuclear genes, and combining cranial, dental, and multivariate statistical evidence, in 2018 T. Gorfol and G. Csorba (and in 2019 Gorfol and colleagues) recovered petersi within a clade of Hypsugo, with a sister relationship to H. dolichodon; as a result they transferred the Asian members of Falsistrellus ( affinis, mordax, petersi) to Hypsugo . At the specific level, following Gorfol and Csorba, comparison between specimens of “ affinis ” from Myanmar (Mon State) and Cambodia and those from the Indian subcontinent revealed morphological differences (skull and dental characters, number of caudal vertebrae, bacular form), with the result that the Myanmar and Cambodia specimens were reidentified as H. dolichodon. Earlier, specimens of affinis from India and Sri Lanka had been treated as belonging to mordax . Further studies with genetic data are needed to determine the exact distribution of affinis and its real relationship to mordax and petersi, including whether they are all conspecific (the name mordax has priority), as was previously suspected, for example by C. M. Francis and Hill in 1986 and Corbet and Hill in 1992; comparisons ofthe three are complicated by the fact that mordax is the only one with a type specimen that includes a skull. Gorfol and Csorba also reported that preliminary investigations suggested potentially undescribed forms (unpublished) in the group. Monotypic.

Distribution. India (Uttarakhand, West Bengal, Maharashtra, Kerala, and Tamil Nadu), C Nepal, Sri Lanka (Central and Uva provinces), SC China (SE Tibet [= Xizang], Yunnan, and Guangxi), and NE Myanmar (known only from type locality in Kachin State).

Descriptive notes. Head-body 43-51 mm, tail 30-41 mm, ear 12-15 mm, hindfoot 7-8 mm, forearm 37-8-41-5 mm. Pelage of the Chocolate Pipistrelle is soft, dense, and relatively long; upperparts are chocolate-brown, almost black, lighter on head and neck, with pale gray hairtips, giving slightly grizzled appearance; underparts are also dark,slightly paler than dorsum, with grayish-white bases and dark tips; uniformly white near anus. Wing membranes, ears, and naked parts of face are blackish brown. Ears are broad and rounded, more or less triangular; tragusis broad and pointed at anterior end. Muzzle is moderately long and narrow. Wing membranes attach to base of outertoe. Tail is long, with nine caudal vertebrae. Baculum of a specimen from India is broad, proximally widened and ventrally deeply fluted, with no distal expansion. Skull has relatively low braincase in comparison to rostrum, which is robust and elongated, with lateral and median depressions; forehead is almost flat; zygomata are robust with low but evident postorbital processes; basicranial pits are poorly developed; coronoid process of each half mandible exceeds C, in height. I? is short and broad; I* is well developed, equal in height to secondary cusp of I*, and with distinct accessory cusp internally; it is usually situated closely adjacent to C', which is unicuspid and broad at base; P* is of moderate size, subequal to I” in crown area and slightly displaced internally; C! and P* are not in contact, according to specimens from India, but in specimens from China they be may slightly in contact; P,is situated in tooth row, and is about two-thirds the crown area and height of P,. Condilo-canine lengths are 13-7-14-5 mm, and maxillary tooth row lengths are 5-5 7 mm. In 1969, S. Pathak and T. Sharma reported two different karyotypes under different names from the same locality in India (Maharashtra), 2n = 36 and FN = 50 for the form then named Pipustrellus affinis, and 2n = 34 and FN = 46 for P. mordax; they differ by a small pair of subtelocentric chromosomes.

Habitat. The Chocolate Pipistrelle is apparently confined to high altitudes up to ¢. 2000 m. In Sri Lanka, it has been recorded in Central Highlands at 1846 m, in Nepal at 2000 m, and in Darjeeling district, India, at 1452 m. In Myanmar,it was recorded in Bhamo, a town beside the Irrawaddy River surrounded by deciduous and evergreen forest.

Food and Feeding. Chocolate Pipistrellesfly at heights of 5-6 m and catch small flying insects such as mosquitoes.

Breeding. No information.

Activity patterns. The Chocolate Pipistrelle is nocturnal. It appears to spend the day in the roofs of buildings or in cracks and small holes in tree trunks, emerging at dusk to feed on insects, which it captures around human habitations and clearings. It may hibernate for a short period during cold and frosty weather.

Movements, Home range and Social organization. Chocolate Pipistrelles roost in small colonies of 5-6 individuals.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as Falsistrellus affinis),, in view ofits wide distribution and expected large population, and because it is unlikely to be declining quickly. In parts of South Asia, the Chocolate Pipistrelle is threatened by habitat loss, largely through commercial logging and conversion of land for agriculture, as well as human interference at roosting sites. Further studies are needed into its taxonomy, distribution, abundance, reproduction, and ecology.

Bibliography. Acharya et al. (2010), Bates & Harrison (1997), Bates et al. (2005), Boitani et al. (2006), Chheang et al. (2013), Corbet & Hill (1992), Csorba, Bumrungsri, Francis, Bates, Gumal & Kingston (2008f), Das (2003), Dobson (1871b), Ellerman & Morrison-Scott (1951), Francis (2008a), Francis & Hill (1986), Gorfol & Csorba (2018), Gorfol, Csorba et al. (2014), Gorfol, Furey et al. (2019), Heaney et al. (2012), Hill & Harrison (1987), Koopman (1994), Molur et al. (2002), Pathak & Sharma (1969), Phauk et al. (2013), Phillips (1980), Ruedi, Eger et al. (2017), Simmons (2005), Smith & Xie Yan (2008), Srinivasulu & Srinivasulu (2012), Tate (1942b), Wroughton (1916, 1918a), Yapa & Ratnavira (2013).