Journal of Threatened Taxa | www.threatenedtaxa.org | 26 April 2025 | 17(4): 26864–26871

 

 

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) 

https://doi.org/10.11609/jott.9562.17.4.26864-26871

#9562 | Received 17 December 2024 | Final received 31 January 2025 | Finally accepted 11 March 2025

 

 

An update on the status of some Data Deficient bat species from India

 

Uttam Saikia 1         , Manuel Ruedi 2          & Rohit Chakravarty 3       

 

1 Zoological Survey of India, North Eastern Regional Centre, Risa Colony, Shillong, Meghalaya 793003, India.

2 Department of Mammalogy and Ornithology, Natural History Museum of Geneva, BP 6434, 1211 Geneva 6, Switzerland.

3 Nature Conservation Foundation, 1311, “Amritha”, 12th Main, Vijayanagar 1st Stage, Mysore, Karnataka 570017, India.

3 Bat Conservation International, 500 N Capital of TX Hwy, Bldg. 1, Suite 175, Austin, Texas 78746, United States.

1 uttamzsi@gmail.com (corresponding author), 2 manuel.ruedi@geneve.ch, 3 rohitchakravarty@ncf-india.org

 

 

 

Editor: H. Raghuram, Sri S. Ramasamy Naidu Memorial College, Sattur, Tamil Nadu, India.                   Date of publication: 26 April 2025 (online & print)

 

Citation: Saikia, U., M. Ruedi & R. Chakravarty (2025). An update on the status of some Data Deficient bat species from India. Journal of Threatened Taxa 17(4): 26864–26871. https://doi.org/10.11609/jott.9562.17.4.26864-26871

  

Copyright: © Saikia et al. 2025. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

 

Funding: US was supported by Zoological Survey of India for field work. RC acknowledges Rufford Small Grants Foundation (Grant no. 24477-2), Idea Wild, and Elisabeth-Kalko Stiftung (OroVerde).

 

Competing interests: The authors declare no competing interests.

 

Author details: Uttam Saikia is working as a scientist in Zoological Survey of India, Shillong. His primary research interest includes systematics of the bat fauna of India especially in the Himalayan region. Manuel Ruedi is the curator of vertebrates in the Natural History Museum of Geneva. He is interested in the systematics and biogeography of the Old World bats using an integrative approach. Rohit Chakravarty works for Nature Conservation Foundation and Bat Conservation International leading projects related to bat conservation in various parts of India

 

Author contributions: All authors participated in the field surveys. US wrote the mss with inputs from other authors. All authors finally checked and approved the manuscript.

 

Acknowledgements: US is thankful to Dr. Dhriti Banerjee, Director, Zoological Survey of India for institutional support. US and MR also express thanks to the Director, ZSI for permitting institutional collaboration between ZSI and NHMG, Geneva. US and RC also express gratitude to the officials of the Forest Departments of Uttarakhand, Himachal Pradesh, Manipur, Meghalaya, Mizoram for survey permissions & logistical support. R. Chakravarty acknowledges funding support from Rufford Foundation, Idea Wild and Elisabeth Kalko Stiftung (OroVerde).

 

 

Abstract: Globally, a significant percentage of bat species are classified as Data Deficient indicating a shortage of sufficient data on distribution and abundance to make a status assessment. Among these species, 12 species also occur within the political boundary of India. Based on scattered data generated over the last eight years, an update is presented on the occurrence status of five of the Data Deficient bat species in India. A call for a renewed push in field studies is needed to enhance the understanding of the chiropteran fauna of India. A National Red List Assessment of Indian Bat fauna is also suggested as a priority exercise for developing a country- specific conservation plan.

 

Keywords: Chiroptera, Himalaya, morphometrics, National Red List, status assessment, Vespertilionidae.

 

 

introduction

 

The order Chiroptera comprising bats is one of the most speciose and widespread mammalian groups with 1,482 known species globally (Mammal Diversity Database 2024; Simmons & Cirranello 2024). Despite being diverse with a cosmopolitan distribution, bats tend to be understudied by zoologists and ecologists alike and therefore lack baseline information on many of these species. Consequently, a significant number of bat species remain poorly documented as reflected from global assessments. Out of the 1,336 bat species assessed by the International Union for Conservation of Nature globally, 236 species have been listed as Data Deficient (DD) indicating insufficient knowledge on abundance, distribution or taxonomic uncertainty to make a conservation assessment (IUCN 2024). In India, about 134 bat species are known (Srinivasulu et al. 2024) out of which 12 species are currently listed as DD by IUCN. Among these DD species, the Rainforest Tube-nosed Bat Murina pluvialis, Joffre’s Pipistrelle Mirostrellus joffrei, Kashmir Cave Bat Myotis longipes, Burmese Whiskered Bat Myotis montivagus, and Hodgson’s Long-eared Bat Plecotus homochrous are known by a few locality records in the Himalayan and northeastern region of India (Image 1). Starting 2017, the present authors had the opportunity to do bat sampling in several localities in the states of Uttarakhand, Himachal Pradesh, Manipur, Meghalaya, and Mizoram resulting in fresh collection of specimens of these species and additional field data. These specimens were deposited in the National Zoological Collection of the North Eastern Regional Centre (NERC) of Zoological Survey of India, Shillong. Based on these studies, an update is presented on the occurrence status of five of these bat species in India.

 

 

Observations

 

Murina pluvialis (Image 1A, Image 2)

The Rainforest Tube-nosed Bat M. pluvialis was discovered in 2012 from the village of Laitkynsew (780 m) in eastern Khasi Hills of Meghalaya (Ruedi et al. 2012) and until recent times was the only known from the type specimen (NERC registration No V/M/ERS/603). An old specimen in Zoological Survey of India, Shillong, collected from Shillong City (V/M/ERS/9565), is found to represent this species. Two female specimens were also collected from Risa Colony (1,540 m) and Madan Laban (1,600 m) within Shillong City in 2015 and 2018, respectively (V/M/ERS/323 and 444). A male specimen was mist netted in February 2015 at Tangsen (1,060 m) near cave Lanshat in eastern Jaintia Hills of Meghalaya (V/M/ERS/353). It was also reported that a large series of specimens identified as Murina cyclotis in the Field Museum of Natural History, Chicago indeed represent M. pluvialis (Ruedi & Csorba 2017). These specimens, 28 in total, were collected between 1952 and 1955 by American collector Walter N. Koelz and his Indian associate Rup Chand from Mawphlang (1,840 m) in eastern Khasi Hills district of Meghalaya. Another individual of this bat was observed by the first author in a torpid state hanging from a wall fig Ficus pumila in Shillong City in March 2021. Although M. pluvialis is superficially similar to the sympatric congener M. cyclotis, the former can be identified by their blackish hair roots on the ventral pelage as against lighter ventral hairs all along the length in the latter. It may further be mentioned that due to external similarity with M. cyclotis, this bat might have been overlooked or confused with the latter species in previous studies. Considering the large number of specimens collected in the past and the aforementioned recent records, this species is presumably of common occurrence in Khasi and Jaintia Hills region of Meghalaya. Interestingly, all the individuals recorded in Shillong were from an urban landscape, atypical for a reportedly forest dwelling group like Murina indicating this species is adepted to a human dominated landscape as well. The sampling efforts so far in other parts of northeastern India have failed to record this bat yet.

 

Mirostrellus joffrei (Image 1B, Image 3)

The Joffre’s Pipistrelle M. joffrei was another poorly known species with a very few specimen records globally until recently. Previously, variously classified under genera Nyctalus, Pipistrellus, and Hypsugo, the species is now included under the newly erected monotypic genus Mirostrellus (Görföl et al. 2020). Currently it is known from several localities in Nepal, India, Myanmar, Vietnam, and China (Saikia et al. 2017; Görföl et al. 2020; Mou et al. 2024). In India, this bat was initially reported from Meghalaya and Sikkim (Saikia et al. 2017), it is now known from the western Himalayan state of Uttarakhand (Chakravarty et al. 2020) and Manipur and Mizoram in the eastern Himalayan Region as well (Saikia & Meetei 2022; Saikia & Chakravarty 2024). In Lamdan Village (1,270 m) in Manipur, two female specimens were captured in mist nets among mixed pine forest while in the periphery of Murlen National Park in Mizoram, three individuals were caught in mist nets near a water hole by the first author indicating their fairly common occurrence in suitable habitat. In Mandal (1,500 m) and Ansuya (2,200 m) in Chamoli District of Uttarakhand, this bat is not uncommon in the forested habitat (Rohit Chakravarty pers. obs. 30th March 2018).  Most females caught by the third author in Uttarakhand between late March and early May were pregnant. In comparison to other syntopic species of Mandal, M. joffrei seems to have an earlier onset of pregnancy (Rohit Chakravarty pers. obs. 30th March 2018, 6th and 19th April, 2021).  Primarily occurring in higher elevations, the Indian records range 1,260–2,200 m and all of them were recorded in forest habitat or the vicinity. In China, this bat was reported at an elevation of 2,434m (Mou et al. 2024). Considering the extensive distribution in the Indo-Malayan Region from across the Himalayan Range, the southeastern Asia and extending till southern China and apparently not so uncommon occurrence, a fresh global status assessment of this species is warranted.

 

Myotis longipes (Image 1C, Image 4)

The Kashmir Cave Bat M. longipes is another poorly known species in the Indian Himalaya. In view of insufficient information on the extent of occurrence, natural history, threats and conservation status, the IUCN categorized this species as DD (Kruskop 2016). Originally described from Bhima Devi Cave in Kashmir, this bat is reportedly known from Lawghar and Nangarhar Province of Afghanistan, Kashmir, Uttarakhand, and Meghalaya in India, western Nepal and Guizhou in southwestern China (Smith & Xie 2008; Kruskop 2016; Chakravarty et al. 2020). The previous record from Siju Cave in Meghalaya (Sinha 1994) which forms the basis for subsequent mentions of this species from Meghalaya is erroneous and represents Chinese Water Myotis M. laniger. In fact, our ongoing studies have indicated that all records of this bat in eastern Nepal and Indo-China might represent M. laniger. During the sampling in the western Himalaya, this species was recorded in a few localities in Solan District in Himachal Pradesh and also in Mandal, Woodstock School, Benog Wildlife Sanctuary and Ansuya Devi in Uttarakhand between elevations of 1,440–2,582 m (Chakravarty et al. 2020; Ruedi et al. 2021). All previous mentions of M. mystacinus from Himachal Pradesh indeed represent M. longipes (Ruedi et al. 2021). In Himachal Pradesh, this species was exclusively located in their day roost in caves, sometimes numbering over 500 individuals and sharing space with R. lepidus and R. sinicus. Although individual species were roosting in close proximity (could be influenced by space constraints), there was no intermixing between species. In Uttarakhand, the individuals were mist netted across forest brooks. The parturition period of this species in Himachal Pradesh is reported to be in June–July and females reportedly form maternity colony (Saikia et al. 2011) and females were observed with pups in early June in 2017.

 

Myotis montivagus (Image 1D, Image 5)

Burmese Whiskered Myotis M. montivagus was described from Yunnan in China in 1874 and belongs to a taxonomically cryptic group of small-footed Myotis. Formerly, this species was recognized to have four subspecies with a wide distribution range from southeastern Asia, northeastern India, and peninsular India. Based on a detailed analysis of cranio-dental characters, all four subspecies were elevated to species rank (Görföl et al. 2013). The nominate subspecies Myotis montivagus montivagus has now been recognized as a distinct species Myotis montivagus, which is reportedly distributed in Yunnan in southern China, northern Myanmar, Laos, and Mizoram in northeastern India (Görföl et al. 2013). The peninsular Indian records of this species are now considered to belong to the Western Ghat endemic Peyton’s Myotis Myotis peytoni. Till recently, the only genuine record of M. montivagus from India was from Sairep (1,500 m) in Lunglei District of Mizoram (Mandal et al. 2000). Sairep Village is situated in at a hilltop surrounded by dense evergreen vegetation and reportedly had a rich assemblage of bat fauna. The first author also revisited this area in 2023, M. montivagus could not be recorded. During the surveys, the first author also collected another specimen of this species from Siju Cave in southern Garo Hills in Meghalaya in 2018 (V/M/ERS/457). This bat was captured in a mist net set in front of the cave during evening hours, suggesting a subterranean roosting habit. This bat was again recorded from the periphery of Murlen National Park in Mizoram in 2022. Two individuals were mist netted around a water hole in a jhum field along Vapar-Murlen Road (1,480 m) although the surroundings had a dense covering of evergreen and semi-evergreen forest. Craniodentally, the Siju and Mizoram specimens agree well, but the former has larger morphological and cranial dimensions (Table 1). The call structure of this species from India has been described (Saikia & Chakravarty 2024). The Indian records for this bat lie between an elevation range of 70–1,500 m indicating adaptation to a broad elevation range.

 

Plecotus homochrous (Image 1E, Image 6)

Hodgson’s Long-eared Bat Plecotus homochrous, previously considered a synonym or a subspecies of the Brown Long-eared Bat Plecotus auritus, was recently assigned specific status (Spitzenberger et al. 2006). It is categorized as DD on account of insufficient information on the area of occupancy and population trend (Srinivasulu & Srinivasulu 2019). Recent surveys in Uttarakhand reported the species from four different locations: Devalsari, Dhanaulti, Ansuya, and Shokharakh ranging 1,700–3,000 m in elevation (Chakravarty et al. 2020). Between mid-April and mid-May in 2018, 2019, and 2021, this species was caught 17 times within the elevation of 2,000–3,000 m at Ansuya, Kanchula and Chopta in Kedarnath Wildlife Sanctuary, Chamoli District, Uttarakhand indicating that the bat is commonly occurring in suitable habitat in the western Himalaya. Four pregnant females were caught on 03 May 2018, and in late April 2021 between the elevation of 2,700–3,000 m. Differences were observed in the elevation ranges of P. homochrous and sympatric congener Plecotus wardi in Kedarnath Wildlife Sanctuary in Uttarakhand. The two species overlapped at 3000 m (the highest sampling point) but P. wardi was never caught below that elevation. Dietary studies show that P. homochrous is a dietary specialist probably predominantly consuming Noctuid moths (Chakravarty et al. 2023).

 

 

Conclusion

 

Evidently, the global status of a large number of bat species remains obscure at present including several Indian species. This is especially true for bats that occur in mountain ranges (Chakravarty et al. 2024). Although some information on the national status of five of these DD species occurring in the Himalaya and the hills of northeastern India has been updated, a lot more needs to be documented. To improve the knowledge of the bat fauna of the country, field studies specifically aimed at the DD and lesser known species should be considered a priority. Besides occurrence data, these studies should aim to generate biological information like breeding, population, diet, and also assess present and future threats. In the light of currently available information, afresh IUCN Red List status assessment of at least a few of these species like M. joffrei, M. longipes, and P. homochrous. This is important since the conservation policy decisions are mostly planned and implemented at the national level and guidelines for such exercises are already available (IUCN 2012).

 

Table 1. Morphometrics of the five species of Data Deficient bats from India 1.

Parameters

(in mm)

Murina pluvialis

(V/M/ERS/353,444)

Mirostrellus joffrei (V/M/ERS/650684, 687)

Myotis longipes

(V/M/ERS/439-442)

Myotis montivagus

(V/M/ERS/457697, 704)

Plecotus homochrous

(V/M/ERS/654)

FA

32, 34.1

36.7, 38.4, 38.0

36.6 (35.9–37.2)

39.4, 40.2, 42.9

36.2

HFCL

6.3, 7.9

7.6, 7.9, 8.7

8.7 (8.1–9)

8.7, 9.0, 10

7.3

TIB

15.3, 16.9

14.5, 14.7, 16.7

16.4 (15.8–16.8)

15.9, 17.4, 19

17.6

E

13.5, 14.9

8.6, 11.5

15.5 (14.9–16.3)

12.1, 12.9, 13.6

34.9

TR

6.4, 7.1

3.3 6.0

6.9 (6.5–7.5)

6.3, 6.9, 6.0

13.7

3MT

32

37.0, 37.7, 39.4

33.9 (33.4–34.9)

37.8, 40.2

34.2

4MT

30.6

36.8, 36.9, 38.0

33.2 (32.7–34.0)

36.6, 41.9

33.7

5MT

30.0

32.2, 32.6, 34.6

32.9 (32.6–33.6)

35.8, 40.5

32

GTLi

15.37, 15.65

14.9, 14.92

14.00, 13.67

15.51, 16.12

15.84

CBL

13.8

13.65, 13.02

13.3, 12.72

15.2

14.00

CCL

13.32, 13.92

14.12, 14.23

12.33, 12.06

14.28, 14.44

13.72

ZW

8.55, 9.00

10.82, 10.67

8.27, 8.57

10.82, 11.37

7.92

BW

7.33, 7.40

7.73, 8.00

6.71, 6.97

7.36, 7.57

7.53

MAB

7.37

8.68

7.08

8.25

8.43

POC

3.91, 4.16

4.58, 4.95

3.38, 3.44

4.10, 4.15

3.78

CM3

5.06, 5.17

5.08, 5.22

5.28, 5.15

6.25, 6.52

5.18

M3-M3

5.20, 5.32

7.43, 7.02

5.58, 5.63

7.17, 7.08

5.82

C1-C1

3.93, 3.95

5.16

3.64, 3.70

4.22, 4.64

2.79

MLi

10.30, 10.6

10.74, 11.74

10.40, 10.11

11.90, 13.12

9.95

CM3

5.63, 5.74

5.40, 5.68

5.48, 5.40

6.55, 7.13

5.84

COH

3.50

3.73, 4.00

2.72, 2.70

3.89, 3.00

2.66

1 FA—Forearm length | E—Ear length | TR—Tragus length | HFCL—Hindfoot length including claw | FA—Forearm length | TB—Tibia length | 3MT—3rd metacarpal length | 4MT—4th metacarpal length | 5MT—5th metacarpal length | GTLi—Greatest length of skull including incisors | CBL—Condylobasal length | CCL—Condylocanine length | ZB—Zygomatic breadth | BW—Braincase width | MAB—Mastoid breadth | POC—Postorbital constriction | CM3—Maxillary toothrow length | M3M3—Width across third molars | C1C1—Width across canines | MLi—Length of mandible including incisors | CM3—Mandibular tooth row length | COH—Coronoid height.

 

 

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