Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 April 2021 | 13(5): 18319–18323
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.7014.13.5.18319-18323
#7014 | Received 20 December 2020 | Final
received 07 April 2021 | Finally accepted 09 April 2021
First distribution record of the Asiatic Toad Bufo
gargarizans Cantor, 1842 from India — Dibang Valley in Arunachal Pradesh
Sahil Nijhawan 1, Jayanta Kumar Roy 2,
Iho Mitapo 3, Gata Miwu 4, Jibi Pulu 5 & M.
Firoz Ahmed 6
1 Department of
Anthropology, University College London, London WC1H 0BW, United Kingdom.
1 Institute of Zoology,
Zoological Society of London, Regent’s Park, London NW1 4RY, United Kingdom.
1 Nature Conservation
Foundation, Mysore, Karnataka 570017, India.
2,6 Herpetofauna Research
and Conservation Division, Aaranyak, Bishnu Rabha Path, Beltola Tiniali, Guwahati, Assam 781028, India.
3,5 Dibang Adventures, Lower Dibang Valley, Roing, Arunachal
Pradesh 792110, India
4 Anini, Dibang
Valley, Arunachal Pradesh 792101, India.
1 s.nijhawan@ucl.ac.uk,
2 roy.jayantakumar47@gmail.com (corresponding author),
3 ihomitapo@gmail.com, 4
gatamiwu78@gmail.com, 5 pulujb@gmail.com, 6 mfa.aaranyak@gmail.com
Editor: S.R. Ganesh, Chennai
Snake Park, Chennai, India. Date
of publication: 26 April 2021 (online & print)
Citation: Nijhawan, S., J.K. Roy, I. Mitapo, G. Miwu, J. Pulu & M.F. Ahmed (2021). First distribution
record of the Asiatic Toad Bufo gargarizans Cantor, 1842 from India — Dibang Valley in Arunachal Pradesh. Journal of Threatened
Taxa 13(5): 18319–18323. https://doi.org/10.11609/jott.7014.13.5.18319-18323
Copyright: © Nijhawan et al. 2021. 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: Panthera.
Competing interests: The authors
declare no competing interests.
Acknowledgements: These observations
were made during SN’s doctoral fieldwork in Dibang
Valley. SN is grateful to Panthera, Wildcats Conservation Alliance, Chester Zoo, and
Ravi Shankaran-Inlaks Shivdasani
Foundation for research funds. JKR and MFA acknowledge financial support from
SERB, Department of Science and Technology, Govt of India. We are thankful Prof Jing Che, Dr Simon
Stuart, Dr Kanto Nishikawa and two anonymous reviewers for helping make the
manuscript better. We thank the Arunachal Pradesh Forest Department for
research permits. Finally, we are
indebted to Idu Mishmi host families and guides in Dibang Valley for their hard work, persistence and
knowledge.
Abstract: Bufo
gargarizans, a species complex, has a wide
distribution ranging from Japan to south-western China, Vietnam, and Russia but
was not previously reported from India.
Surveys conducted in Dibang Valley district of
Arunachal Pradesh near the Indo-Tibetan border with China in 2014–15 revealed
previously unreported specimens of the toad genus Bufo. Based on photographic comparisons with
morphological characteristics obtained from published literature, we have
identified the Bufo from Dibang
Valley as the Asiatic Toad Bufo gargarizans Cantor, 1842. Individuals of the species reported from
Dibang have a wide mid dorsal line in the dorsum,
rarely observed in Bufo gargarizans
except in the sub-populations on the Tibetan Plateau.
Keywords: Arunachal Pradesh, Bufo gargarizans, Dibang Wildlife Sanctuary, new country record, new
distribution.
Bufo gargarizans
Cantor, 1842 is a large-sized terrestrial toad (SVL males: 62–106 mm;
females: 70–121 mm) distributed in eastern Asia, known to occur up to 4,300m
(Fei et al. 2012). The populations on
the Tibetan Plateau are some of the highest known records of any toad species
(Fei et al. 2009; Zhan & Fu 2011). This species complex has a wide distribution
range spanning most of central, southeastern, and northeastern China, the Russian far-east up to the Amur
River Valley, throughout the Korean Peninsula, Japan, and Vietnam (IUCN SSC
Amphibian Specialist Group 2019; Frost 2021 but see Che et al. 2020 for
suggestions for a new taxonomic split for populations in Tibet). No records of the Bufo
gargarizans species complex had been previously
reported from India (Dinesh et al. 2020).
In this paper, we report the first and the only known occurrence of Bufo gargarizans
from the Indian subcontinent.
From July to October
of 2014 and 2015, while conducting mammalian surveys in Dibang
Valley district of Arunachal Pradesh, India, we opportunistically encountered
several individuals of a previously unreported Bufo
species in the high-altitude marshlands near the Tibetan border. As we walked through the marshes, many toads
jumped out of the grass in front of us drawing our attention. While no specimens were collected, a few
different individuals were photographed and only one individual was measured
for its SVL (Image 1). Based on
preliminary photographic comparisons with the morphologically similar Asian
Toad Bufo gargarizans
Cantor, 184, known to occur in similar elevation range in southeastern Tibet (Frost 2021), we have identified the Bufo species from Dibang
as Bufo gargarizans.
Here, we present a detailed description of the Dibang
specimens including the microhabitats where they were encountered. Though we suggest that the Dibang specimens are likely to be Bufo
gargarizans, we call for further morphological
and molecular work to confirm the taxonomy of this newly recorded toad from
India.
Dibang Valley district (9,129km2)
is located between 27.133–28.7830N and 94.1–95.90E along
the Indian border with Tibet (China) in the state of Arunachal Pradesh. The northern part of the district falls
within the Dibang Wildlife Sanctuary (4,149km2). The region receives a mean annual rainfall of
1932–4442 mm (Guhathakurta et al. 2020). It is a heavily mountainous landscape with
altitude ranging from 300m in the river valleys to 5,300m at the high peaks
along the Indo-Tibetan border. This vast
altitudinal range supports diverse habitats from tropical and subtropical wet
forests in low-lying areas through temperate wet forest in mid elevations to
alpine scrub and bare rock over 4,100m.
Lying at the juncture of two biogeographical realms (Indomalayan
and Palearctic), Dibang Valley forms part of the
eastern Himalaya biodiversity hotspot and supports an exceptionally high
species diversity across all floral and faunal groups (Sheth
et al. 2020).
Bufo gargarizans
from Dibang Valley
Morphologically, the
toad species reported from Dibang Valley (Image
1) share the following significant similarities with Bufo
gargarizans (see Fei Liang et al. 2012
for morphological details of the species).
The specimens from Dibang Valley were dorsally
dark gray to olive-brownish in color
with a wide mid-dorsal line. The dorsal
surface and flanks were rough with large warts.
The ventral side from snout to vent was granular, grayish-yellow
or light yellow in colour; belly smooth, and granular. Irregular dark spots or stripes were present
on the ventral surface of the body and the flanks extending from the dorsal
surface of the parotid gland to the thigh.
There were 2–3 larger warts on the inner side of the upper eyelid. The head was triangular, tympanum large and
distinct, parotid glands were bean-shaped.
The tip of fingers and toes were soft and round. The SVL of the only individual of unknown sex
measured was 62mm (n= 1).
We recorded abundant
breeding populations of Bufo gargarizans at three different locations in two
river valley systems inside Dibang Wildlife Sanctuary
(Figure 1). All observations were made
in the altitudes of 2,250–3,200 m near the Tibetan border. No specimens were recorded outside this
altitudinal range. The microhabitat for
all three breeding populations was similar—flat wetlands and marshes with
stagnant water, covered with thick aquatic vegetation (Image 2). A few individuals were also encountered in
small rainfed puddles and pools along human trails inside the forest, within
close proximity to the marshlands. We
also observed calls of the species between 14.00h and 16.30h. The toads were encountered only during
surveys conducted in the summer and monsoon period from June until late
September and not in surveys carried out in winter and spring—late January to
early April.
These substantive
morphological similarities and the proximity of the location of the specimens
to the known distribution range of Bufo gargarizans indicate that the specimens from Dibang Valley likely belong to the Bufo
gargarizans species complex.
Bufo gargarizans
is locally known as ‘Pambo’. The toad holds
special importance for the animistic Idu Mishmi
people of the Dibang Valley. According to an Idu Mishmi tale, the supreme spirit of the high mountains,
‘Gõlõ’, once lived as a toad. Since the Idu fear
and respect Gõlõ, harming the toads is a strict
taboo. The Idu
Mishmi do not touch, kill or consume the toad, simply moving away when the
toads are seen so as to not step on them accidently.
Discussion and
Conclusions
Given the
opportunistic nature of this study based on photographic comparisons and the
taxonomic ambiguities around this species complex, our findings should be seen
as preliminary and warrant further investigation. In this vein, we highlight
three notable observations.
Firstly, the
distribution and taxonomic classification of the Bufo
gargarizans species complex has
historically been a matter of much discussion and disagreement (Zhan & Fu,
2011). Zarevskij
(1926) reclassified the populations on the Tibetan plateau as Bufo tibetanus
based on some morphological differences, in particular a wide mid dorsal line
in the dorsum of Bufo tibetanus
which is less prominent in Bufo gargarizans found elsewhere (Liu & Hu 1961),
gaining the support of a number of scientists later on (e.g., Borkin & Matsui 1987; Fei et al. 2009, 2012). The Dibang
specimens, too, had a wide mid dorsal line akin to that reported from the
Tibetan Plateau; however, despite significant morphological differences, a
molecular study by Zhan & Fu (2011) did not find any support for the
separation of B. tibetanus and
B. gargarizans into distinct species. In 2019,
the IUCN Amphibian Specialist Group recognized all previously thought species
within the Asian Toad complex as a single species Bufo
gargarizans (IUCN Amphibian Specialist Group
2019). Recently, Che et al. (2020)
suggested that Bufo gargarizans
from Tibet be reclassified as Bufo cf.
andrewsi Schmidt, 1925 and predicted that the
taxonomically widespread Bufo gargarizans will be partitioned into distinct
species. Thus, the taxonomy of this
species complex continues to be a matter of doubt and debate.
Secondly, in Dibang Valley, we observed the species exclusively during
the peak monsoon months from July to September, with no individuals observed in
field surveys conducted between January and April. Fei et al. (2012), on the other hand,
reported January to June as the breeding season for Bufo
gargarizans species complex. We believe that this difference could be due
to a longer and colder winter in the high-elevation wetlands of Dibang Valley.
Lastly, and importantly,
the species was not recorded in an earlier amphibian survey conducted
across the Dibang River basin over an altitudinal
gradient of 200–3,500m (Roy et al. 2018).
While the high-altitude marshland habitats from where we report Bufo gargarizans
were not surveyed during Roy et al.’s (2018) study, they sampled
comparable elevations in the region during the monsoon season but did not
encounter the species. This may indicate
a narrow distribution of the species in Dibang
Valley, restricted to areas with a specific habitat type (i.e., seasonal
marshlands) within a small elevation range (2,250–3,200m). This is particularly
interesting as studies from other parts of Bufo
gargarizans’ range have reported
a wide altitudinal distribution (120–4,300m) for the species, spanning a
variety of habitats including flood plains, river valleys, coniferous, mixed
and deciduous forests, grasslands, and meadows (IUCN SSC Amphibian Specialist
Group 2019).
In light of the
ambiguous taxonomic classification of this species complex, we recommend that
future research employ molecular techniques to conclusively ascertain the
taxonomy of the specimens found in the upper reaches of the Dibang
River basin. Future research should also
explore the species’ distribution and ecological correlates in other river
valleys of the Dibang basin and across the
Indo-Chinese borderlands in Arunachal Pradesh, particularly in the neighboring river basins of Subansiri,
Siang, and Lohit, which are also likely to host
high-altitude wetland habitats similar to those where Bufo
gargarizans was encountered in
the Dibang Valley.
Finally, since Bufo gargarizans had not been previously reported from India
(Dinesh et al. 2020), our present documentation from Arunachal Pradesh forms
the first record of the species from India, throwing open prospects to better
understand its geographic range.
For
figure & images - - click here
References
Borkin, L.J. & M.
Matsui (1987) “1986”. On systematics of two toad species of the Bufo bufo complex
from eastern Tibet. In: Ananjeva, N.B. & L.J. Borkin (eds.). Sistematika
i ekologiia amfibii i reptilii: 43–53. Zoologicheskii Instituta SSSR,
Leningrad.
Che, J., K. Jiang, F. Yan & Y. Zhang (2020). Amphibians and
Reptiles in Tibet—Diversity and Evolution [In Chinese with English abstracts
and species descriptions]. Chinese Academy of Sciences, Science
Press, Beijing, 803pp.
Dinesh, K.P., C. Radhakrishnan, B.H. Channakeshavamurthy, P. Deepak & N.U. Kulkarni (2020). A Checklist of
Amphibians of India with IUCN Conservation Status. Version 3.0. updated till
April 2020. available at https://www.amphibians.org/wp-content/uploads/2020/05/2020_Indian_Amphibian_checklist.pdf.
Accessed on 16 March 2021.
Fei, L., S.Q. Hu, C.Y. Ye & Y.Z. Huang (2009). Fauna Sinica. Amphibia. Volume 2. Anura. Chinese
Academy of Science. Science Press, 958pp.
Fei, L., C.Y. Ye & J.P. Jiang (2012). Colored
Atlas of Chinese Amphibians and their distributions. Sichuan Publishing
House of Science & Technology, Sichuan, 619pp.
Frost, D.R. (2021).
Amphibian Species of the World: An Online Reference. Version 6.1 Electronic
Database accessible at: https://amphibiansoftheworld.amnh.org. Accessed on 16
March 2021.
Guhathakurta, P., S. Khedikar, P. Menon, A.K. Prasad, N. Sangwan
& S.C. Advani (2020). Observed rainfall variability and changes over
Arunachal Pradesh state. ESSO/IMD/HS/Rainfall Variability/02(2020)/26. Climate
Research and Services, India Meteorological Department, Ministry of Earth
Science, Pune. 29pp.
IUCN SSC Amphibian Specialist Group (2019). Bufo
gargarizans. The IUCN Red List of Threatened
Species 2019: e.T78017839A63877827. Downloaded on 14 September 2020. https://doi.org/10.2305/IUCN.UK.2019-1.RLTS.T78017839A63877827.en
Liu, C. & S. Hu (1961). Chinese Tailless
Amphibians. Science Press, Beijing.
Roy, J.K., R.H. Begum & M.F. Ahmed (2018). Amphibians of the Dibang River Basin, Arunachal Pradesh: an annotated
checklist with distribution records. Journal of Threatened Taxa 10(15):
12940–12952. https://doi.org/10.11609/jott.4249.10.15.12940-12952
Sheth, C., M.F. Ahmed, S.
Banerjee, N. Dahanukar, S. Dalvi, A. Datta, A.D. Roy, K. Gogoi, M. Gogoi, S. Joshi, A. Kamdar, J.
Krishnaswamy, M
Kumar, R.K. Menzies, S. Molur, S. Mukherjee, R. Naniwadekar, S. Nijhawan, R.
Raghavan, M. Rao, J.K. Roy, N. Sharma, A. Sinha, U. Srinivasan,K.,
Tamma, C. Umbrey, N. Velho,
A. Viswanathan & R. Yumnam (2020). ‘The devil is in the
detail’: Peer-review of the Wildlife Conservation Plan by the Wildlife
Institute of India for the Etalin Hydropower Project,
Dibang Valley. Zoo’s Print 35(5):
1–78.
Zarevskij, S.F. (1926). Notes on some Batracians from the Palaearctic region. Annuaire du Musée Zoologique de l’Académie des Sciences de Leningrad 26: 74–78.
Zhan, A. & J.Z. Fu (2011). Past and present: Phylogeography of the Bufo
gargarizans species complex inferred from
multi-loci allele sequence and frequency data. Molecular Phylogenetics and
Evolution 61: 136–148. https://doi.org/10.1016/j.ympev.2011.06.009