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 email@example.com
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: firstname.lastname@example.org
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: www.iucnredlist.org. Last accessed on 22
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