Hypsugo savii (Bonaparte, 1837)

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 : 30-31

14. Hypsugo savii (Bonaparte, 1837)

(Savi’s Pipistrelle)

New material: 1 F, 31.03.2018, Mandal village, Chamoli district , Uttarakhand, V /M/ERS/633 .

Morphological description of specimen: The Uttarakhand specimen had a forearm of 37.7 mm. The pelage was light brown dorsally and creamy–white ventrally, with thick and silky fur. Dorsal hairs were unicoloured whereas ventral hairs had darker roots and whitish tips. The ears, muzzle, patagium and feet were dark, contrasting against its light pelage colouration ( Fig. 11D ). The wing and tail membranes were black and essentially naked on both sides. The shape of the ear was rather like a Pipistrellus but with a short and wide tragus. Wing membrane joined at the middle of the metatarsus. A small calcar lobe was present, and the tail tip projected out of the tail membrane by about 4 mm.

The skull and dentition were relatively robust. The rostrum was broad and with two frontal depressions and elevated to the braincase in almost a straight line ( Fig. 13B ). A weak sagittal crest was present. The palate was concave and very deep. The zygomatic arches were delicate. The upper incisors were bicuspid. Only one upper premolar was present which was equal to the canine in basal area and almost reaching the height of the canine. The coronoid process was situated much higher than the condylar process. Lower molars were myotodont. These morphological features and mensural data agree well with the Central Asian, sand–coloured subspecies Hy. s. caucasicus found in Afghanistan (Benda & Geisler 2015) or Tajikistan ( Benda et al. 2024).

DNA: COI sequence from an Uttarakhand specimen ( V /M/ERS/633) proved to be very similar (within 1.8% sequence divergence) to Hy. savii ’s lineage D described recently by Gojznikar & Mayer (2024) for Central Asia. This lineage D included sequences from southern Mongolia (GB OM370825 and MW367769 ) labelled as “ Hy. stubbei ” or “ Hy. alaschanicus ” ( Fig. 4 ). These savii ’s lineage D sequences were more distant (>7%) from various other lineages of Hy. savii from the Western Palearctic region (e.g., OQ 706648, see Gojznikar & Mayer 2024) and even more so (>9%) from sequences of true Hy. alaschanicus from Mongolia or China (GB OR 467319 or MF459671 ).

Distribution and ecological notes: Hy. savii is primarily a Palaearctic species with a supposed intrusion into northern India ( Juste & Paunović 2016). However, the records of this species from Pune in Maharashtra ( Korad & Yardi 2004) and from Ambala in Haryana ( Neuhauser 1970) were regarded as misidentifications because Hy. savii is unlikely to be found in the hot plains ( Benda & Gaisler 2015). The report of a specimen from Gilgit in Pakistan administered Kashmir ( Chakraborty 1983) which was collected and initially identified by J. Scully as Vesperugo borealis was also considered by John Hill as doubtful. It was therefore suggested that the Oriental limit of distribution of the species could be the Hindu Kush barring aside a single record from Kamu, Nuristan province in eastern Afghanistan ( Benda & Gaisler 2015). Our specimen from Mandal (1600 m) therefore represents the first authentic record of this species from the Western Himalayas and India as a whole, extending its distribution to the southeast by about 900 km.

The adult female was caught in a mist net set over a shallow, shaded stream along the edge of an oak forest. We recorded short frequency–modulated (FM) calls with a bandwidth of 53.14 kHz with an end frequency of 29.2 kHz. The peak frequency was recorded at 42.11 kHz ( Table 6). The call frequencies were superficially similar to those recorded in European Hy. savii ( Russo & Jones 2002) . The echolocation calls were recorded inside a room so that the bat could be collected after recording. Therefore, the call may resemble the ones emitted in dense clutter. Natural search phase calls are likely to have distinct FM and QCF components, with lower bandwidth and longer duration. In the study area (Kedarnath Wildlife Sanctuary), its calls overlap with those of Mirostrellus joffrei ( Chakravarty et al. 2020) .

Taxonomic note: Dobson (1871) described Pipistrellus austenianus from the Khasi Hills in north–eastern India, which has been regarded as a possible synonym of Hy. savii (e.g., Bates & Harrison 1997). However, as no critical evaluation of the only known specimen from Cherrapunjee with other Hypsugo spp. has been made so far, this taxonomic assignement is best considered as doubtful. The high lineage diversity found in the mitochondrial DNA of Hy. savii ( Fig. 4 ) further questions the taxonomic rank to be assigned to these divergent clades ( Gojznikar & Mayer 2024). We indeed concur that in the absence of nuclear genetic markers, it is currently impossible to decide whether each major clade represent distinct species or subspecies, or simply reflect the complex phylogeographic history of a single polytypic and widespread species ( Benda & Gaisler 2015). We can only support that the Uttarakhand specimen is part of Hy. savii ’s lineage D and has external morphology corresponding well to Hy. savii caucasicus .

Figures

FIGURE 4: Neighbor-joining tree reconstruction of examined vespertilionids, miniopterids and molossids COI sequences and based on the K2P matrix in Table S2. Branches are proportional to the number of mutational steps. Sequence names are composed of the first two letters of the genus, followed by the species name, the GenBank number (or field number for newly sequenced samples), and the region of origin. Samples from India are highlighted in bold face.

FIGURE 11. Portraits of some bat species recorded from the Western Himalayas during the present study.A) Ba. darjelingensis (released animal), B) Ep. pachyomus (ZSI–NERC V/M/ERS/420), C) Hy. affinis (ZSI–NERC V/M/ERS/638), D) Hy. savii (ZSI–NERC V/M/ERS/633), E) Mu. cf. aurata (released animal), F) Mu. cyclotis (ZSI–NERC V/M/ERS/425), G) Mu. huttonii (ZSI–NERC V/M/ERS/424), H) Mu. huttonii (released animal from Ansuya, Uttarakhand).

FIGURE 13. Dorsal, ventral, and lateral view of cranium and lateral and ventral view of mandible of A) Hy. affinis (ZSI–NERC V/M/ERS/638), and B) Hy. savii (ZSI–NERC V/M/ERS/633) from the Western Himalayas.