Indian roundleaf bat

The Indian roundleaf bat ("Hipposideros lankadiva"), also known as the large Ceylon leaf-nosed bat or Kelaart’s leaf‐nosed bat is a species of bat in the family Hipposideridae. It is endemic to the Indian subcontinent, with marginal populations also detected in Southeast Asia. Its natural habitats are subtropical or tropical dry forests and caves. "Hipposideros schistaceus" is a synonym for the species.
"H. lankadiva" is a large leaf-nosed bat and is yellowish-brown in color. A key trait of the bats is the reduced fourth supplementary leaflet on the noseleaf, along with a lack of a fleshy elevation behind the posterior nose-leaf and the absence of white patches on the shoulders, which helps differentiate from similar species such as "H. armiger" and "H. diadema".
The bat has three subspecies that occur in India, Sri Lanka, and Myanmar. The Indian subspecies, "H. l. indus", is smaller than the ones found in Sri Lanka and Myanmar, although there are no other characteristics that differentiate the subspecies.
The bat has been assessed by the IUCN as least concern, although the species is threatened in parts of its range by roost disturbance and collection for consumption and medicinal use.
Taxonomy.
The species was described by Kandy in the central hills of Sri Lanka. Anderson considered the species to be restricted to Sri Lanka, but then also recorded it from Bhamo in Myanmar on the basis on two immature specimens. Anderson then described 5 taxa from India: "H. indus indus" from Gersoppa , which he distinguished from "H. lankadiva" on the basis of size; two new subspecies, "H. i. mixtus" from Kolar and "H. i. unitus" from Mundra; and one additional species, "H. schistaceus" from Vijayanagar. Kemp reported specimens of "H. lankadiva" from the Siju Cave in the Garo Hills in India. Tate included lankadiva, unitus, indus, mixtus, and schistaceus in a ‘mainland offshoot of the diadema group' in 1941, but did not specify their taxonomic status.
Hill treated "indus" as a distinguishable subspecies of "H. lankadiva" and mixtus as a synonym. He included "unitus" as a subspecies of "H. lankadiva" without comment. "H. schistaceus" was maintained as a separate species. This arrangement was followed by Corbet and Hill who considered the distribution of "H. lankadiva" as being confined to central and southern peninsular India and Sri Lanka.
Upon the collection of specimens in West Bengal, Agrawal suggested a review of the status of subspecies of the bat was necessary. Bates and Harrison included all specimens of "H. lankavida" from Sri Lanka in the nominate subspecies "H. l. lankadiva". This material averaged significantly larger than those seen from throughout peninsular India. All Indian material was referred to "H. lankadiva indus", with "schistaceus", "mixtus" and "unitus" also included as synonyms.
The taxon "Hipposideros schistaceus" was previously considered to be distinct at the species level, but is now considered a synonym of "H. lankadiva".
The bat belongs to the "diadema" species group. There are 3 subspecies of the bat:
Description.
This species is large leaf-nosed bat. The pelage of the bat ranges from pale cream to brown and is darker on the head and shoulders, while being relatively paler on the belly. They have an average forearm length of 83.5 mm, with a range of 75-99 mm. Their average weight is 59 g.
The bat has four supplementary leaflets on its nose-leaf, with the fourth leaflet being reduced. The intermediate leaf is expanded, with an inflated and swollen central part, and an evenly concave surface. The posterior leaf is brown and its upper border is trilobate.  The ears of the species are large and acutely pointed, and had their posterior margins slightly concave behind the tip.
The bats found in Myanmar are considerably larger in size than those found in India, and are comparable to those found in Sri Lanka.
The bat has are nine pairs (1-9) of metacentric and six pairs (10-15) of subtelocentric autosomes. The X is the largest element of the male karyotype and metacentric in nature. The Y, on the other hand, is subtelocentric. The morphometrical details for the male karyotype of this species are given in Table 2. The sum of the mean length of the chromosomes of a haploid set has been calculated as 39.25 p.m. The various autosomes fall in the range of 1.23 - 3.77 p.m. The mean length of X is 3.82 p.m and that of Y 1.05 p.m.
Biology.
This bat does not hibernate.
Reproduction.
The bats mate once a year. They have a gestation period of 260 days, after which a single young is born.
Diet.
The bats are insectivores. Their diet is composed mainly of coleoepterans, especially scarabaeids, and other large, hard-bodied, and slow-flying insects, like nuptial ants and bugs. The high proportion (79%-100%) of beetles in the observed feces of these bats in Sri Lanka suggest that they forage for food selectively.
Echolocation.
The bat echolocates at a very low frequency, with the calls being at a mean of 78.33 kHz, with a range of 62.96-82.96 kHz. The species' calls have a comparatively short CF component and a longer tampering FM component, suggesting that the bat uses these to hunt insects in narrow spaces. This can also be explained considering that the bats roost in deep recesses with narrow openings.
The cochlea of this bat is at an intermediate state between that of non-specialized bats and long-constant-frequency bats.
Distribution and habitat.
The bat is found patchily but widely across the Indian subcontinent, with some records also being found in Myanmar in Southeast Asia.
India.
It is found in Andhra Pradesh, Karnataka, Madhya Pradesh, Maharashtra, Manipur, Meghalaya, Mizoram, Orissa, Rajasthan, Telangana, Tripura, and West Bengal.
Sri Lanka.
It is found in the Central, Eastern, North Central, Sabaragamuwa, Southern, Uva and Western provinces.
Bangladesh.
It has been recorded in Netrokona in Bangladesh.
Myanmar.
The bat has been recorded in Kachin state.
The bat has a wide but patchy distribution through a variety of habitats. Despite its wide distribution, the bat is known only from a few locations in India and Sri Lanka. In Sri Lanka, the bat is known from the southern dry zone, lower foothills and wet zone hills. It is found up to an elevation of 1,000 meters above sea level.
It is a gregarious species roosting in groups of 50 to several thousand individuals. It roosts in caves, old disused tunnels, old temples, old forts, dark deep channels under dam sites and cellars under old buildings.
Conservation.
The bat is assessed as least-concern by the IUCN because of its wide distribution, its tolerance of a number of different habitats, its large population, and lack of significant population decline.
Threats to the bat include roost disturbance, as the bat seems to be extra-sensitive to disturbance of roosts, and the collection of the bats for medicinal and biological use.