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Defensive behaviour of Melanobatrachus indicus (Anura: Microhylidae) in the Western Ghats, India

Behavioural avoidance, cryptic and aposematic
colouration, toxic and distasteful skin secretions and
defensive postures are all strategies that have evolved
in anuran amphibians in response to predators (Wells,
2007; Toledo, Sizima and Haddad, 2011).
Here we report the anti-predatory behaviour in the
Endangered black microhylid frog (Melanobatrachus
indicus) which is endemic to the Western Ghats in India
(Biju et al., 2004). A rarely observed frog, this species is
ranked 58 on the Zoological Society of London’s EDGE
amphibians list because of its unique evolutionary
history and threat status (Isaac et al., 2012).
The observations described here were observed in a
single specimen at the Anamalai Tiger Reserve in Tamil
Nadu. The specimen was found at 15:00hrs under a
large decaying log in a swampy patch of semi-evergreen
forest at 1,300 m asl. GPS location is not provided here
due to existing collection pressures. When this individual
was disturbed the initial defensive behaviour was to
remain motionless. When the animal was picked up, the
forelimbs and hind limbs were brought in close to the
body and the back became arched (Fig. 1). This form of
defensive behaviour is known as contraction and its main
function is to avoid injuries to the frog during subjugation
and ingestion by its predators (Toledo, Sizima and
Haddad, 2011). Melanobatrachus indicus has brightly
coloured orange patterns on the ventral regions of the
chest, upper arms and on the undersides of the thighs.
This aposematic colouration remained largely hidden
when this individual exhibited contraction behaviour.
We sus pe ct t ha t o nl y a li mi te d p or ti on o f t hi s s pe ci es ’
anti-predator behavioural repertoire was observed and
suspect that it exhibits thanatosis revealing its brightly
coloured ventral surface, a behaviour exhibited by other
species with conspicuously coloured undersides (see
Escobar-Lasso and González-Duran, 2012).
Acknowledgements. The authors would like to thank Nature
Conservation Foundation, the Tamil Nadu Forest Department
for official permission to undertake amphibian surveys
(WL5/28696/2012) and the Zoological Society of London’s
EDGE Fellowship for financial support.
Herpetology Notes, volume 6: 607-608 (2013) (published online on 27 December 2013)
Defensive behaviour of Melanobatrachus indicus (Anura:
Microhylidae) in the Western Ghats, India
Arun Kanagavel1,2 and Benjamin Tapley3*
1 Wildlife Information Liaison Development (WILD) society,
96, Kumudham Nagar, VIlankuruchi Road, Coimbatore 641
035, India
2 Conservation Research Group, St. Albert’s College, Banerji
Road, Kochi 682 018, India
3Zoological Society of London, Regent’s Park, London, United
Kingdom, NW1 RRY
*Corresponding author; e-mail:
Figure 1. A. Contracting behaviour in the black microhylid
frog Melanobatrachus indicus. A. Lateral view. B. Dorsal
Arun Kanagavel & Benjamin Tapley
Biju, S.D., Vasudevan, K., Bhuddhe G.D., Dutta, S., Srinivasulu
,C., Vijayakumar, S.P. (2004): Melanobatrachus indicus. In:
IUCN (2013). IUCN Red List of Threatened Species. Version
2013.1. Available at: Last accessed on 22
August 2013.
Escobar-Lasso, S., González-Duran, G.A. (2012): Strategies
employed by three Neotropical frogs (Amphibia: Anura) to
avoid predation. Herpetology Notes 5: 79-84.
Isaac, N.J.B., Redding, D.W., Meredith, H.M., Safi, K. (2012):
Phylogenetically-informed priorities for amphibian conservation.
PLoS ONE 7: e43912.
Toledo, L.F. Sizima, I., Haddad, C.F.B. (2011): Behavioural
defences in anurans: an overview. Ethology Ecology and
Evolution 23: 1-25.
Wells, K.D. (2007): The Ecology and Behaviour of Amphibians.
Chicago, University of Chicago Press.
Accepted by Philip de Pous
... We conducted questionnaire-based interview surveys from August 2013 to May 2016, where LEK data correspond to species presence, associated habitats and locations while distinctively patterned but is rarely encountered and not well studied; some data are available on habitat associations, but its reproductive biology is unknown (Daltry & Martin, 1997;Kanagavel & Tapley, 2013; Table 2) and there are no published accounts of the species being utilised by people. Walkerana phrynoderma is an uncommon, rainforest-dependent, ground-dwelling brown frog that bears a superficial resemblance to several other frogs in the region (Biju et al., Are local and traditional knowledge suitable tools for conservation of threatened amphibians? ...
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Globally, amphibians are declining more rapidly than any other vertebrate group. A general shortage of funding for the support of focused scientific studies led us to investigate local and traditional ecological knowledge as an alternative data source for amphibian conservation. In this context, we undertook a questionnaire-based interview survey with forest-dwelling indigenous and non-indigenous communities across the Anamalai Hills, within the southern Western Ghats of India, to gather ecological knowledge on three cryptic and threatened frog species. Our results suggest that local communities possess ecological knowledge of frogs and that the magnitude of this knowledge is influenced by gender, community type, education, and age. Accuracy of local knowledge was primarily influenced by the morphological distinctiveness of the focal species, but cultural association and utilisation were also important factors especially for the enigmatic purple frog Nasikabatrachus sahyadrensis, which has uses in medicine and amulets.
The Black Microhylid Frog Melanobatrachus indicus is a rare and endangered species known only from very few specimens from the southernmost part of the Western Ghats. A good population of these species was reported for the first time from the highland montane shola forests Marayoor, Idukki district, Kerala. The present report forms the highest altitude record for the species, about 1700m and also accounts for the most numerous populations ever recorded for the species from the Western Ghats. An updated review of the present distribution of the Black Microhylid frog is also provided.
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Among vertebrates, defensive behaviours have been reviewed for fishes, salamanders, reptiles, birds, and mammals, but not yet for anuran amphibians. Although several defensive strategies have been reported for anurans, with a few exceptions these reports are limited in scope and scattered in the literature. This fact may be due to the lack of a comprehensive review on the defensive strategies of anurans, which could offer a basis for further studies and insights on the basic mechanisms that underlie these strategies, and thus lead to theoretical assumptions of their efficacy and evolution. Here we review the present knowledge on defensive behavioural tactics employed by anurans, add new data on already reported behaviours, describe new behaviours, and speculate about their origins. A total of 30 defensive behaviours (some with a few sub-categories) are here recognised. The terminology already adopted is here organised and some neologies are proposed. Some of the behaviours here treated seem to have an independent origin, whereas others could have evolved from pre-existent physiological and behavioural features. The role of predators in the evolution of defensive behaviours is still scarcely touched upon and this overview adds data to explore this and other evolutionary unsolved questions.
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The amphibian decline and extinction crisis demands urgent action to prevent further large numbers of species extinctions. Lists of priority species for conservation, based on a combination of species' threat status and unique contribution to phylogenetic diversity, are one tool for the direction and catalyzation of conservation action. We describe the construction of a near-complete species-level phylogeny of 5713 amphibian species, which we use to create a list of evolutionarily distinct and globally endangered species (EDGE list) for the entire class Amphibia. We present sensitivity analyses to test the robustness of our priority list to uncertainty in species' phylogenetic position and threat status. We find that both sources of uncertainty have only minor impacts on our 'top 100' list of priority species, indicating the robustness of the approach. By contrast, our analyses suggest that a large number of Data Deficient species are likely to be high priorities for conservation action from the perspective of their contribution to the evolutionary history.
Consisting of more than six thousand species, amphibians are more diverse than mammals and are found on every continent save Antarctica. Despite the abundance and diversity of these animals, many aspects of the biology of amphibians remain unstudied or misunderstood. The Ecology and Behavior of Amphibians aims to fill this gap in the literature on this remarkable taxon. It is a celebration of the diversity of amphibian life and the ecological and behavioral adaptations that have made it a successful component of terrestrial and aquatic ecosystems. Synthesizing seventy years of research on amphibian biology, Kentwood D. Wells addresses all major areas of inquiry, including phylogeny, classification, and morphology; aspects of physiological ecology such as water and temperature relations, respiration, metabolism, and energetics; movements and orientation; communication and social behavior; reproduction and parental care; ecology and behavior of amphibian larvae and ecological aspects of metamorphosis; ecological impact of predation on amphibian populations and antipredator defenses; and aspects of amphibian community ecology. With an eye towards modern concerns, The Ecology and Behavior of Amphibians concludes with a chapter devoted to amphibian conservation. An unprecedented scholarly contribution to amphibian biology, this book is eagerly anticipated among specialists.
IUCN Red List of Threatened Species
  • S D Biju
  • K Vasudevan
  • G D Bhuddhe
  • S Dutta
  • C Srinivasulu
  • S P Vijayakumar
Biju, S.D., Vasudevan, K., Bhuddhe G.D., Dutta, S., Srinivasulu ,C., Vijayakumar, S.P. (2004): Melanobatrachus indicus. In: IUCN (2013). IUCN Red List of Threatened Species. Version 2013.1. Available at: Last accessed on 22 August 2013.
  • L F Toledo
  • I Sizima
  • C F B Haddad
Toledo, L.F. Sizima, I., Haddad, C.F.B. (2011): Behavioural defences in anurans: an overview. Ethology Ecology and Evolution 23: 1-25.