Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 April 2026 | 18(4): 28729–28733
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.10206.18.4.28729-28733
#10206 | Received 11 October 2025 | Final received 15 February 2026|
Finally accepted 16 March 2026
First record of Wall’s Krait Bungarus walli
Wall, 1907 (Reptilia: Squamata: Elapidae)
from Assam, and diagnostic keys to the kraits of India
Bijay Basfore
1, Abhi Medhi 2,
Nazrul Islam 3, Rathin Barman 4,
Madhurima Das 5,
Anjana Singha Naorem
6 & Jayaditya
Purkayastha 7
1,6 Department of Zoology, Cotton
University, Panbazar, Guwahati 781001, Assam, India.
2 Ozapara, Azara,
Near- Sabhaghar, Guwahati, Assam 781015, India.
3,4 Wildlife Trust of India, F-13,
Sector-8, Noida (National Capital Region), Uttar Pradesh 201301, India.
5,7 Help Earth, 16 Raghunath
Choudhury Path, Lachitnagar, Guwahati, Assam 781007, India.
5 Department of Zoology, Assam Don
Bosco University, Sonapur, Assam 782402, India.
1 zoo2491005_bijay@cottonuniversity.ac.in,
2 medhiabhijit328@gmail.com, 3 nazrul@wti.org.in, 4 rathin@wti.org.in,
5 madhurima.das@dbuniversity.ac.in, 6
anjanasingha@cottonuniversity.ac.in
(corresponding author), 7 mail.jayaditya@gmail.com (corresponding
author)
Editor: S.R. Ganesh, Kalinga
Foundation, Agumbe, India. Date of
publication: 26
April 2026 (online & print)
Citation: Basfore, B., A. Medhi, N.
Islam, R. Barman, M. Das, A.S. Naorem & J. Purkayastha (2026).
First record of Wall’s Krait Bungarus walli Wall, 1907 (Reptilia:
Squamata: Elapidae) from Assam, and diagnostic keys
to the kraits of India. Journal of Threatened Taxa 18(4): 28729–28733. https://doi.org/10.11609/jott.10206.18.4.28729-28733
Copyright: © Basfore et al. 2026. 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: The study was funded by the Wildlife Trust of India (WTI) and
conducted in collaboration with Help Earth.
Competing interests: The authors declare no competing interests.
Acknowledgements: We express our sincere gratitude to Maheshwar Basumatary, Saurav Mardi, Bishal Basumatary and Keshav Pathak for their valuable support and guidance during the fieldwork. We also extend our appreciation to the Divisional Forest Officer of Kachugaon Division, as well as to all the Range Forest Officers and the frontline forest staff of Raimona National Park, for their assistance in the field and dedication to conservation of the landscape. The authors further acknowledge the Bodoland Territorial Council (BTC), Assam Forest Department and the International Fund for Animal Welfare (IFAW) for its long-term collaboration and partnership with the Wildlife Trust of India (WTI) in the recovery and conservation of the Greater Manas Landscape.
Kraits of the genus Bungarus Daudin, 1803 are
highly venomous ophiophagous snakes belonging to the
family Elapidae found in southern and south-eastern
Asia across Afghanistan, Bangladesh, Bhutan, Brunei, Cambodia, China, India, Indonesia,
Iran, Laos, Malaysia, Myanmar, Nepal, Pakistan, Singapore, Sri Lanka, Taiwan,
Thailand, and Vietnam (Wallach et al. 2014; Midtgaard
2022; Uetz et al. 2026). The genus currently
comprises 18 recognised species, nine of which are
known to occur in India: Bungarus andamanensis Biswas & Sanyal,
1978; B. bungaroides (Cantor, 1839); B. caeruleus (Schneider, 1801); B. fasciatus
(Schneider, 1801); B. lividus Cantor, 1839; B.
niger Wall, 1908; B. sindanus
Boulenger, 1897; B. suzhenae
Chen, Shi, Vogel, Ding & Shi, 2021, and B. walli
Wall, 1907 (Uetz et al. 2026).
Among these, Bungarus
walli, commonly referred to as Wall’s Krait, was
originally described from Fyzabad (at present
Faizabad), Uttar Pradesh, India (Wall 1907). The species is known from the
Indian subcontinent, with confirmed occurrences in India, Bangladesh, Nepal,
and Bhutan (Smith 1943; Lenz 2012; Wallach et al. 2014; Ahsan & Rahman
2017; Ghosh et al. 2021). Within India, B. walli
exhibits a fragmented distribution and has been reported from a limited number
of states, including Bihar, Odisha, Uttar Pradesh, and West Bengal (Figure 1)
(Whitaker & Captain 2004; Bhattacharjee & Sarkar 2021). Recently, B.
walli has been reported from Tripura, marking the
first-ever record of the species from northeastern India (Deb et al. in press).
In addition to distributional records, existing studies have reported aspects
of the species’ natural history, including habitat preference and venom effects
(Sharma et al. 2013), leucism (Devkota
et al. 2020), reproductive biology (Ray et al. 2020; Ray et al. 2023), and
scavenging behaviour (Banik
& Ray 2023).
While a few reports of Bungarus sindanus walli are present from Maharashtra State in western
India (Nande & Deshmukh 2007; Deshmukh et al.
2016), they have now come to be identified as Bungarus
sindanus complex based on a smaller number and
extent of bands, yellowish supralabials among other
variations, distinct from B. walli, which is
more of an eastern Indian species. In northeastern India, six species of Bungarus are currently known: B. bungaroides, B. fasciatus,
B. lividus, B. niger,
B. suzhenae, and B. walli,
of which all except B. suzhenae and B. walli have been reported from Assam (Basfore et al. 2024; Gerard et al. 2024; Deb et al. in
press). The present study confirms the occurrence of the fifth species of Bungarus recorded from Assam, based on data of a
live uncollected subadult encountered in the Raimona
National Park.
The Raimona
National Park is located on the northern bank of the Brahmaputra River and falls
under the Kachugaon Forest Division of the Kokrajhar District in Assam, India. It lies along the
Indo–Bhutan international border, with the Sonkosh
River forming the western boundary and the Saralbhanga
River marking the eastern extent. To the northern side, Raimona
shares a contiguous landscape with the Phipsoo
Wildlife Sanctuary of Bhutan, while the Buxa Tiger
Reserve of West Bengal borders it to the western side. The occurrence of B. walli in Assam is likely attributable to its close
proximity to West Bengal, a region where the species is already known to occur.
On 17 July 2025, at 2030 h,
during a herpetofaunal survey, a juvenile Bungarus walli (Image
1), approximately 460 mm in total length, was encountered in the Western
Range (26.673° N, 89.972° E; elevation: 117 m) of the Raimona
National Park. The specimen was found actively foraging across a moist,
semi-shaded habitat along a shallow forest stream surrounded by dense
vegetation. The area is characterised by thick
undergrowth dominated by climbers, shrubs, ferns, and grasses along the margins
of the narrow stream. The adjoining forest is composed of tall evergreen and
semi-evergreen trees with a dense canopy, creating a humid and shaded
environment.
Upon encounter, the snake was
photographed, and essential meristic and morphometric data were recorded.
Identification was carried out based on the following diagnostic characters:
(1) Dorsal scale rows: 19:17:17; (2) Ventrals: 207;
(3) Supralabials: seven, with the 3rd and
4th touching the eye; (4) 2nd supralabial
narrower than the 3rd; (5) Infralabials: four; (6) mid-body
vertebral scales distinctly broader than long; (7) body distinctly compressed;
and (8) glossy black colouration with 66 white,
unpaired transverse bands, all consistent with existing published descriptions
(Table 1).
A comparative account of the
newly encountered specimen with published literature is provided in Table 1,
while Table 2 presents diagnostic keys to the kraits of India. Other herpetofaunal species recorded at the site included Irawaddy Crested Lizard Calotes
cf. irawadi, Eastern Bronzeback
Dendrelaphis proarchos,
Bangladesh Skittering Frog Euphlyctis adolfi, Northern House Gecko Hemidactylus
aquilonius, Common House Gecko Hemidactylus frenatus,
Flat-tailed House Gecko Hemidactylus platyurus, Littoral Bullfrog Hoplobatrachus
litoralis, Bhamo Frog Hylarana humeralis,
Cope’s Assam Frog Hylarana leptoglossa, Theobald’s Ranid
Frog Hylarana tytleri,
Nepal Cricket Frog Minervarya nepalensis, Pierre’s Cricket Frog Minervarya
pierrei, and Bengal Monitor Lizard Varanus bengalensis.
The present record of Bungarus walli from
Assam represents a significant extension of its known geographic range,
approximately 778 km east of the type locality in Uttar Pradesh (Uetz et al. 2026), about 393 km from the recent confirmed
record in Tripura (Deb et al. in press), and about 62 km from its nearest
previously known record from West Bengal (Banik &
Ray 2023). Thus, the present study highlights the significance of systematic herpetofaunal surveys in transboundary landscapes, having
contiguous forests with countries like Bhutan, as these regions may harbour undocumented taxa. The finding also emphasises the role of Raimona
National Park, a recently established protected area, as a valuable site for documenting
poorly known or range-extended herpetofaunal species.
Bungarus walli
is often misidentified as B. caeruleus or B.
sindanus, and as a medically important venomous
snake, such misidentifications are of concern, as existing polyvalent
antivenoms may exhibit variable efficacy across different Bungarus
species (Chippaux 2017). Therefore, accurate
identification and targeted inventory of herpetofauna are essential not only
for conserving biodiversity but also for enhancing public health preparedness
in snakebite-prone regions, such as western Assam, where agriculture is the
primary livelihood activity and brings people into frequent contact with
snakes.
Table 1. Comparison
of Bungarus walli from Raimona National Park, Assam with published
descriptions.
|
Character |
Present specimen |
Wall (1907) |
Smith (1943) |
Whitaker & Captain (2004) |
Bhattacharjee & Sarkar
(2021) |
|
Total length (in mm) |
460 |
393–1517 |
1640 (Male) & 1500 (Female) |
1518 |
- |
|
Dorsal scale rows |
19:17:17 |
19:17:17 |
19 or 21: 17 or 19:17 |
17 or 19:17 or 19:17 |
17 or 19:17 or 19:17 |
|
Ventrals |
207 |
203 |
196–208 |
196–208 |
192–207 |
|
Subcaudals |
55 |
55 |
50–55 |
50–55 |
48–55 |
|
Cloaca |
Entire |
Entire |
- |
Entire |
- |
|
Supralabials |
7 (3 & 4 touching eye) |
7 (3 & 4 touching eye) |
- |
7 (3 & 4 touching eye) |
- |
|
2nd supralabial narrower than 3rd |
Yes |
Yes |
- |
- |
- |
|
Infralabial |
4 |
4 |
- |
- |
- |
|
Preocular |
1 |
- |
- |
1 |
- |
|
Postocular |
2 |
- |
- |
2 |
- |
|
Loreal |
Absent |
- |
- |
Absent |
- |
|
Temporals |
1+2 |
1 (anterior) |
- |
1+2 |
- |
|
Preocular spot |
Absent |
Absent |
Absent |
- |
- |
|
Vertebrals broader than long |
Yes |
Yes |
- |
Yes |
Yes |
|
Number of bands |
66 |
- |
65–80 |
- |
- |
Table 2. Diagnostic
key to the
Kraits of India.
|
Species |
DSR (midbody) |
VEN |
SC |
Dorsal pattern |
Body bands |
Reference |
|
B. andamanensis |
15 |
193–197 |
45–47 (undivided) |
Narrow white or yellowish-white
bands |
39–47 |
Biswas & Sanyal, (1978); Smith (1943) |
|
B. bungaroides |
15 |
220–237 |
44–51 (divided) |
White or pale
yellow bands |
46–60 |
Smith (1943); Das (2018) |
|
B. caeruleus |
15 |
200–217 (234) |
33–54 (undivided) |
Narrow white bands (sometimes
paired) |
29–65 |
Biswas & Sanyal (1978); Slowinski
(1994); Whitaker & Captain (2004) |
|
B. fasciatus
sensu stricto |
15 |
222–228 (male) & 224–231
(female) |
35–37 (male) & 32–36
(female) (undivided) |
Black and yellow bands |
22–27 |
Biakzuala et al. (2023) |
|
B. lividus |
15 |
209–221 |
35–43 (undivided) |
Black or bluish-black |
Absent |
Smith (1943) |
|
B. niger |
15 |
216–231 |
47–57 (undivided) |
Glossy black body |
Absent |
Wall (1908); Smith (1943) |
|
B. sindanus |
17 or 19 |
220–237 |
49–52 (undivided) |
White bands |
- |
Boulenger (1897) |
|
B. suzhenae |
15 |
220–229 |
51–54 (undivided) |
White bands |
26–38 |
Chen et al. (2021) |
|
B. walli |
17 or 19 |
196–208 |
50–55 (undivided) |
Narrow white unpaired bands |
65–80 |
Wall (1907); Smith (1943) |
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