Tadarida insignis (Blyth, 1862)

Saikia, Uttam, Chakravarty, Rohit, Csorba, Gabor, Laskar, Mostaque Ahmed & Ruedi, Manuel, 2025, Taxonomic reassessment of bats from the Western Himalayas, India and description of a new species of the Myotis frater complex (Mammalia, Chiroptera, Vespertilionidae), Zootaxa 5644 (1), pp. 1-78 : 14-15

2. Tadarida insignis (Blyth, 1862)

(East Asian free–tailed bat)

New material: 1 M, 07.04.2021, Mandal village, Chamoli District , Uttarakhand, V /M/ERS/651 .

Morphological description of specimen: The adult male specimen had brown dorsal pelage and lighter brown ventral fur. Individual hairs were short, tips brownish and the bases were creamy white. It had a forearm length of 62.2 mm. The feet were covered with long grey hairs, and small fleshy callosities were present on the sole. The thumb bore a small claw and a prominent thumb pad (2.5 mm in diameter) was present. The tail membrane was essentially naked except for the dorsal region closer to rump and fringes which were covered with short grey hair. The ventral side of the tail membrane was perceptibly lighter coloured than the dorsal side. About one third of the tail protruded out of the membrane and this protruding portion was brownish in colour. Ears were large and broad and closely positioned over the forehead with 8–9 vertical ridges. Ear fringes were covered with short grey hairs on the ventral side. Tragus was shorter, with a slightly constricted basal portion. The plagiopatagium was inserted just above the tibio–metatarsal joint. The penis was pendulous and without any special modifications, the scrotal area was distinctively white coloured.

The skull was robustly built and elongated. The anterior part of the braincase was slightly raised ending in a concavity posteriorly. The lamboid region was also slightly raised. The sagittal crest was absent but lateral lamboid crests were present. The coronoid process in mandible was high and reaching almost to the level of lower canines ( Fig. 7 ).

DNA: We obtained a fragment of 651 bp of the COI gene from this male individual. Compared to homologous sequences from genuine European Ta. teniotis (e.g., Portuguese GB KY581661 or Swiss GB OQ 706681) or from Ta. aegyptiaca from India (GB MG821187 ), this Uttarakhand specimen was clearly very divergent (11–15% K2P distance) and thus did not belong to either of these two species. It was, however, minimally divergent (0.7–0.8% K2P distance) from Asian sequences labelled as Ta. insignis (e.g., from Japan GB MK410371 ) or as Ta. latouchei (e.g., from South Korea GB MK177282 ).

Locality records and ecological notes: Uttarakhand: Dehradun City (670 m), Dehradun District; Taapu Sera (1007 m), Tehri Garhwal district; Mandal village (2000 m), Chamoli district ( Chakravarty et al. 2020; present study). This is the first mention of Ta. insignis from India, but at the same time implies that previous mentions of Ta. teniotis from India represent this species. The Uttarakhand records also extend the westward range of this species by a considerable c. 2500 km. It may be mentioned that based on acoustic call signatures, Ta. teniotis was recently reported from Kali Gandaki canyon of Central Nepal ( Sharma et al. 2021) which might also represent Ta. insignis indicating widespread occurrence across the Himalayan range. The present specimen was attracted to the trapping site by playing social calls of Ta. teniotis recorded in Portugal and was caught in a mist net. A strong and high–flier and preferring to roost in hilly inaccessible areas ( Chakravarty 2017), this species is always difficult to catch and possibly is one of the reasons for its scant records from the country. The echolocation calls from individuals in Uttarakhand had a max–min frequency range of 31.6–9.9 kHz and was described in Chakravarty et al. (2020) as Ta. teniotis .

Taxonomic note: The taxonomic status of Ta. teniotis in India must be reconsidered. There are indeed close similarities in external and craniodental measurements between Ta. teniotis and its Oriental congener Ta. insignis , but according to Benda et al. (2015) the former is a Western Palaearctic species which reaches its eastern limit in Afghanistan, and thus should not be distributed in India. This view is clearly corroborated by our molecular comparisons with up to 15% sequence divergence between European Ta. teniotis and Oriental Ta. insignis ( Table S3). Previous mentions of Ta. “ teniotis ” from India (e.g., Hill 1963, Deshpande & Kelkar 2015, Chakravarty 2017) and elsewhere in the Oriental Region (e.g., Sharma et al. 2020, Taylor 2019, Francis et al. 2010) therefore most likely represent Ta. insignis .

Regarding the two Tadarida species endemic to the Oriental Region ( Ta. insignis and Ta. latouchei ), external and craniodental measurements of the specimen from Uttarakhand (e.g., FA 62.2 mm) is more akin to the larger Ta. insignis (FA> 60 mm), whereas Ta. latouchei is considerably smaller (FA<57 mm; Funakoshi & Kunisaki 2000). However, we found minimal genetic distances (<1%) among all Asian Tadarida variously labelled as “teniotis ”, insignis or latouchei , and sampled over considerable geographic distances (i.e., from India to Japan). Some of these sequences are based on vouchered specimens with verifiable morphological identification, which suggest that typical (large) Ta. insignis (e.g., HNHM–MAM 25862 and 25864, both from Yunnan, China) may share virtually identical mitochondrial sequences with typical (small) Ta. latouchei (ROM MAM 118321 from Laos). Thus, based on mitochondrial markers these two Asian molossids cannot be discriminated and nuclear markers should be investigated before further taxonomic decisions can be taken.

Figures

FIGURE 7. Dorsal, ventral, and lateral view of cranium and lateral and ventral view of mandible of Ta.insignis from Uttarakhand (ZSI–NERC V/M/ERS/651).