Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 August 2020 | 12(11): 16502–16509
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
doi: https://doi.org/10.11609/jott.5994.12.11.16502-16509
#5994 | Received 14 April 2020 | Final
received 12 August 2020 | Finally accepted 17 August 2020
New locality records and call
description of the Resplendent Shrub Frog Raorchestes
resplendens (Amphibia: Anura:
Rhacophoridae) from the Western Ghats, India
Sandeep Das 1 , K.P. Rajkumar 2 , K.A. Sreejith 3, M. Royaltata 4 &
P.S. Easa 5
1–5 Forest Ecology & Biodiversity
Conservation Division, Kerala Forest Research Institute, Peechi,
Kerala 680653, India.
1,2 University of Calicut, Thenhipalam, Malappuram District, Kerala 673635, India.
1 sandeep.koodu@gmail.com (corresponding
author), 2 rajkp16@gmail.com, 3 kalpuzhasreejith@gmail.com,
4 royalgis.gdr@gmail.com, 5 easaelephant@yahoo.com
Editor: Neelesh Dahanukar,
Indian Institutes of Science Education and Research (IISER), Pune, India. Date
of publication: 26 August 2020 (online & print)
Citation: Das, S., K.P. Rajkumar, K.A. Sreejith, M. Royaltata
& P.S. Easa (2020). New locality records and call
description of the Resplendent Shrub Frog Raorchestes
resplendens (Amphibia: Anura:
Rhacophoridae) from the Western Ghats, India. Journal of Threatened Taxa 12(11): 16502–16509. https://doi.org/10.11609/jott.5994.12.11.16502-16509
Copyright: © Das et al. 2020. 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: Kerala State Council for
Science, Technology and
Environment, Kerala Forest
Research Institute (KFRIRP 691/14), EDGE , Zoological Society London.
Competing interests: The authors
declare no competing interests.
Author details: Sandeep Das is Research Scholar at the
Kerala Forest Research Institute, Peechi. He has been
working on amphibians of Kerala since 2010 and is interested in their ecology
and behavior. He is also a ZSL EDGE fellow working on the endangered Purple
Frog Nasikabatrachus sahyadrensis. Rajkumar, K.P.
is a Research Scholar at the Kerala Forest Research Institute, Peechi. His current work deals with the faunal and floral
inventory of marshy grasslands and diversity in Kerala. He is also a ZSL EDGE
fellow working on the Galaxy Frog Melanobatrachus
indicus. Dr. Sreejith K.A. is actively involved in field oriented studies on ecosystem dynamics of
tropical forests in the Western Ghats. By maintaining and monitoring a large
number of permanent plots, he is trying to elucidate the spatial and temporal
variation of biodiversity and its dynamics.
Royaltata, M. is a Research Scholar at the
Kerala Forest Research Institute, Peechi. With
experience in GIS and Remote Sensing, he is interested in their application in
forest management, species distribution, niche-modelling,assessment
of soil water and SWAT in the states of Tamil Nadu and Kerala. Dr. Easa, P.S. has nearly forty years of experience in
wildlife research, conservation and management, and has worked on diverse
groups of animals. He has been with the
Kerala Forest Research Institute, Peechi and is also
associated with a number of Research programs of numerous national and
international institutions
Author contribution: PSE & SD conceived the study;
SD, KPR carried out field work; all authors equally contributed to the data
compilation, analysis and writing the manuscript
Acknowledgements: The authors are thankful to Mr.
G. Harikumar IFS, chief wildlife warden, Kerala
Forest Department (KFD) for permission to conduct the study (WL10-46931/2014,
WL 10-43756/2015). We also thank Mr. G
Prasad, wildlife warden, ENP, assistant wildlife wardens Mr. MP Sanjayan, Mr. M Ajeesh, Mr. S
Sandeep, and Mr. PM Prabhu for necessary permissions
and the help rendered throughout the study period. We acknowledge Kerala State Council for
Science, Technology and Environment (KFRIRP 691/14) and director, Kerala Forest
Research Institute (KFRI) for funding; and extend our gratitude to our lab
members Sarath R. Menon, Prejith
M.P., Prasad T.S., Dhaneesh Bhaskar, Anil Kumar,
Manjunath H.P., Arya K., Roshan Lal, Nithin Divakar, Prijo, Paramasivam (KFD), Kaalidasan (KFD) for the support during call recording, all
the staff from Kerala Forest Department and KFRI for the support in the
field. SD would like to thank EDGE
program, Zoological Society London 2017 for their financial support.
Abstract: The Resplendent Shrub
Frog, Raorchestes resplendens
Biju, Shouche,
Dubois, Dutta, & Bossuyt, 2010 is a
Critically Endangered species endemic to the Western Ghats and was considered
to be restricted to a three-square kilometer patch
atop Anamudi summit.
In this study, we report 36 new locations of the species from the Anamalai massif of the southern Western Ghats. Niche-based prediction modelling suggests
that the species is restricted to Anamalai
massif. The call description of this
frog is also provided for the first time. The preferred microhabitat of the
frog is Chrysopogon grass clumps in
the marshy/swampy montane grassland ecosystem. Restricted to a small area
with controlled burning management practiced in its habitat, R. resplendens needs immediate attention.
Keywords: Anamalai, Critically Endangered,
ground-dwelling bush frog, new distribution record, vocalization.
Introduction
There are currently 8,134
described species of amphibians (Frost 2020) and an average of 144 species
described every year starting from 2004–2015 (Tapley et al. 2018). At the same time, amphibians are the most
threatened group of vertebrates with 41% of the total assessed species under
threatened categories (IUCN 2016).
Considering the total number of new species described between 2004 and
2016, India ranks second globally with 155 species (Tapley et al. 2018). Of these, 75% are from the Western Ghats and
Sri Lanka Biodiversity Hotspot (Myers et al. 2000; Mittermeier et al.
2004). One of the most diverse groups of
frogs in India with the greatest number of species described since 2004 is the
genus Raorchestes known to be a genus of
direct developing rhacophorid frogs (Biju et al. 2010).
Raorchestes resplendens
Biju, Shouche, Dubois, Dutta, & Bossuyt, 2010 is a Western Ghats endemic, medium-sized,
ground-dwelling bush frog. Its prominent
orange colouration and large glands, bordered with black make it distinct from
other species of Raorchestes. The species belongs to the beddomii clade (Vijayakumar et al. 2014) and is
restricted to the Anamalai massif of Western
Ghats. The species is known from only
from its type locality, a three square kilometer
patch of habitat on the Anamudi summit, the highest
peak (2,695m) in Western Ghats in Eravikulam National
Park (ENP) and a site approximately 20km north-east of Anamudi
summit (Joseph et al. 2012). Joseph et
al. (2012) suggested the possibility of a wider distribution of the species
within ENP. Raorchestes
resplendens is assessed as Critically Endangered
(IUCN SSC Amphibian Species Specialist Group 2011).
In this study, we provide
information on the distribution of the species inside and outside the protected
area network based on surveys undertaken in 2015–2018. In addition, we also predict the probable
distribution of the species using niche-based modelling. We also provide the first ever description of
the vocalization of R. resplendens.
Study
Area
Eravikulam National Park (ENP,
10.083–10.333 0N & 77.00—77.166 0E) in Kerala,
India. This 97km2 national
park is one of the few remaining undisturbed patches of the montane
shola-grassland ecosystem in the Western Ghats.
The high elevation protected area located in the Kannan Devan Hills of
Idukki District has a base elevation of approximately 2,000m. ENP experiences tropical montane climate with
average annual rainfall of 5,000–6,500 mm.
More than 60% of the park area is dominated by grasslands with shola
patches in the valleys.
Materials
and Methods
A combination of survey methods
including visual encounter surveys, call surveys, and scan searches (Heyer et al. 1994; Krishnamurthy 2003; Halliday
2006) were used between January 2015 and December 2018 to document the
distribution of R. resplendens. During the breeding season (May−September),
surveys were undertaken from 18.00–02.00 h, as bush frogs are known to be most
active at night (Biju et al. 2010).
Morning and evening surveys were conducted from 08.00–13.00 h and 14.00–17.00
h to record diurnal activity, if any.
Surveys were done in shola-grassland ecosystems above 1,700m especially
inside ENP from where the species was first described and reported. To avoid repeated count and getting maximum
distribution range of the species the surveys were spatially replicated.
Calls of R. resplendens were recorded at approximately 0.5m
distance using ZOOM H4nSP Handy Recorder from four locations in ENP, including Anamudi, Kolukan, Bheemanoda, and Sambamala
area. Ten to 20 calls were recorded for
each individual (n=10 males). Ambient
temperature and snout vent length (SVL) was taken immediately after the
recording using Kestrel 3500 hand-held weather station and a Mitutoyo digital vernier caliper. Analyses of the calls were done using Raven
v1.4 software (Cornell Laboratory of Ornithology, Ithaca, NY, USA) (Bee et al.
2013a,b; Thomas et al. 2014). Temporal
and spectral parameters of calls were measured following definitions of Bee et
al. (2013a,b). Six call properties: call
duration (ms)—time between the beginning of first
pulse and the end of last pulse in a call; call rise time (ms)—time
between the beginning of first pulse and the peak of pulse of maximum
amplitude; call fall time (ms)—time between the peak
of pulse of maximum amplitude and end of
last pulse; inter-call interval—time between end of a call to the beginning of
the next call; call rate—number of calls delivered per minute; and overall
dominant frequency were analyzed for the current
study.
Prediction of distribution and
calculation of extent of occurrence (EOO): Maximum entropy species distribution
modelling software (Maxent) version 3.4.1 was used to predict the distribution
of R. resplendens in Anamalai Hills. We
used approximately 30 arc seconds of data for altitude, precipitation, average
temperature and 19 bioclimatic variables available at the WorldClim
website (http://www.worldclim.org/); 30-m resolution raster dataset layers were
georectified to WGS 1984 43 North Zonation. Geographical coordinates and elevation of
each location were recorded using Garmin Montana 680 and a map with sight
records and the potential distribution was plotted using ArcGIS. The EOO and area of occupancy (AOO) (IUCN
2012) were calculated using the geospatial conservation assessment tool, GeoCAT (Bachman et al. 2011). The EOO was also calculated from species
distribution model by overlaying fishnet squares over the prediction map. Each square covered an area of 4km2. Squares with medium, high, and very high
prediction values were included to calculate the EOO since there were no
records of the species from areas of medium to very low prediction even after
intensive surveys.
Results
and Discussion
Prior to our study the
Critically Endangered (CR) R. resplendens
(Image 1) was known to occur only inside ENP from two locations, Anamudi summit and Poovar. The present study reports 36 new locations
for the species including four from outside ENP (Table 1 and Image 2). The four new locations outside ENP are Njandalamala of Chinnar Wildlife
Sanctuary, a location south-east of ENP in Munnar Forest Division, a location
near the south-west boundary of ENP in Munnar Forest Division, and one location
in the adjacent Anamalai Tiger Reserve of Tamil Nadu
lying close to the north-west boundary of ENP.
The record from near Konalar, Anamalai Tiger Reserve is the lowest elevational record
(1,896m) for the species whereas Anamudi Peak
(2,695m) is the highest. The previously
reported lowest elevational record was from Poovar
(2,522m).
During the three-year study
period from within ENP limits R. resplendens
was encountered 637 times. This
makes the species the second most encountered Raorchestes
species in the grasslands of ENP after Raorchestes
dubois (1,438 times). The unique ground-dwelling habit favored by R. resplendens
could be the reason they evaded researchers for such a long time. They seem to be very sensitive to light and
retreat into grass clumps whenever there is an artificial source of light. Contrary to the tiny bamboo thicket (Arundinaria densifolia)
habitat preferred by the R. resplendens
recorded on Anamudi summit, the majority of the
individuals observed elsewhere were found actively calling and breeding in
marshy/swampy grasslands (Image 3) alongside a water source in the valleys of
the montane grasslands rather than on peaks.
At 21.20h on 28 May 2015, a
single male was observed calling within a grass clump (Chyrsopogon
sp.), 5cm above the ground at a marshy area on the base of Sambamala
Hill (Image 1). Further investigation
resulted in reporting 21 individuals (14 calling males and 7 females) on the
same day from the same habitat patch. A
single male specimen was collected and preserved in the wildlife museum of
Kerala Forest Research Institute, Peechi, Kerala
(KFRI/WLM/A0035). The size was small in
comparison with the details given in published information and from those
field-measured earlier during the study.
The measurements of the preserved specimens are as follows: snout vent
length (SVL) 20.76mm small; head slightly wider than long (HW) 7.88mm, (HL)
7.44mm; snout length (SL) 2.63mm larger than horizontal diameter of the eye
(EL) 2.43mm; snout rounded in dorsal view; minimum distance between upper
eyelids (IUE) is 2.82mm and maximum width of upper eyelid (UEW) is 1.43mm. Distinct and rounded tympanum. Forelimb (FLL) 4.44mm shorter than hand
length (HAL) 4.733mm; fingers with discs and distinct circum-marginal grooves;
webbing absent on fingers and absence of nuptial pads. Unlike many of the species in the genus Raorchestes, the hind limbs are moderately short for
this species; shank length (ShL) 5.37mm shorter than
thigh length (TL) 7.01mm; foot length (FOL) 7.06mm shorter than distance from
the base of inner metatarsal tubercle to the tip of toe IV. Toes with discs and distinct circum-marginal
grooves and reduced webbing. Dorsum with
large orangish glands whereas the creamy white ventrum
is granular.
Call Description
Raorchestes resplendens
males were
observed actively calling from 18.00–02.00 h, during their peak breeding season
in May–September. A total of 141 calls
from 10 males were analyzed for the description of
vocalization. Temperature ranged between
16–20 oC during all recordings. Calls were relatively simple (Figure 1 &
2). The advertisement call (https://doi.org/10.6084/m9.figshare.12781229.v1) had non-pulsatile temporal
structure unlike published calls of other bush frogs including Raorchestes graminirupes,
R. flaviocularis, R. silentvalley,
R. lechiya, R. travancoricus,
and Pseudophilautus kani
(Bee et al. 2013a,b; Vijaykumar et al. 2014; Rajkumar
et al. 2016; Zachariah et al. 2016).
Advertisement calls typically ranged between 58.9–148.8 ms in duration (Table 2).
On an average, the interval between two calls was 2.9 ± 3.6 s, and these
intervals were uncorrelated with SVL or mass (Table 2). The call rise time ( = 46.3 ms ± 29.4 ms; Table 2) was slightly shorter than call fall time
( = 56.7 ms
± 16.8 ms; Table 2).
The calls were typically delivered at rate of 21.5 calls/minute (Table
2).
The spectrum was characterized by
single broad peak with mean dominant frequency of 2.5 KHz
(Figure 3, Table 2).
Distribution
The niche-based prediction model
of distribution in the southern Western Ghats suggests that the species is
restricted to montane grasslands of Munnar-Valparai
area of Anamalai massif. The EOO and AOO calculated using GeoCAT are 289km2 and 84km2, respectively. The approximate EOO calculated based on the
prediction using minimum convex polygon was ~272km2 with the
majority of the area being within ENP and the calculated EOO does not include
areas where our model suggested a low, very low likelihood of occurrence as
there were no actual observations of the species in these areas (Image 2). The species habitat is well-protected as its
distribution largely occurs within protected areas. The areas outside the protected area network
owned by the Kerala Forest Department where the species occurs could be further
designated as eco-sensitive zones to prevent management-based habitat
modifications (Kanagavel et al. 2018). The absence of the species at Anamudi National Park and adjacent areas could be due to
the absence of grassland habitats.
The report of the species from
areas other than Eravikulam National Park including Chinnar Wildlife Sanctuary, grass hills of Anamalai Tiger Reserve, and areas of Munnar Forest Division
ensures better conservation possibilities as these areas are under protection
by the Kerala and Tamil Nadu forest departments. Controlled cold burning of grasslands in
November–February months before the grass gets dry (Image 4), practiced as a
part of habitat management programme in Eravikulam National
Park (Kerala Forests & Wildlife Department 2013), is observed to be
detrimental to slow-moving reptiles and amphibians due to mortality during the
fire and exposed habitat without thick grasses (Image 5) after fires. It was also observed that the mortality is
comparatively less and recolonization in smaller animals is faster in areas
where mosaic pattern is followed while burning (Bhaskar et al. 2019). A further reduction in the size of the burnt
areas in mosaic pattern would ensure better protection to the
herpetofauna. More sampling efforts and
systematic approach is required to understand more about the specific threats
faced by the Raorchestes resplendens. The
management practice of controlled burning, however, might be a threat that
needs immediate attention which is specific to ENP, one of its major
habitat.
Information on the call of the
species will be helpful in further studies as the species is very hard to
detect which might be the possible reason for detecting the species from only two
locations after the initial description of species in 2010 and the knowledge of
the distribution extent can lead to proper conservation action plans for the
Critically Endangered species.
Table 1. Sighting locations of Raorchestes resplendens
from southern Western Ghats.
|
|
Location |
Area |
Lat. |
Long. |
Elevation |
|
1 |
Njandalamala |
Chinnar WS, KL |
10.313642° |
77.141561° |
2346m |
|
2 |
Munnar Division |
Munnar Forest Division, KL |
10.093747° |
77.202883° |
2587m |
|
3 |
Rajamala Tourism Zone |
Eravikulam, KL |
10.143794° |
77.037753° |
1905m |
|
4 |
Naaykollimala |
Eravikulam, KL |
10.142961° |
77.036047° |
1909m |
|
5 |
Wireless Station Rajamala |
Eravikulam, KL |
10.149767° |
77.044744° |
2238m |
|
6 |
Umayamala |
Eravikulam, KL |
10.163153° |
77.072042° |
2169m |
|
7 |
Mesthirikettu |
Eravikulam, KL |
10.184550° |
77.088272° |
2174m |
|
8 |
Range Point |
Eravikulam, KL |
10.187094° |
77.085794° |
2203m |
|
9 |
Bheemanoda |
Eravikulam, KL |
10.195603° |
77.084517° |
2228m |
|
10 |
Kallupaalam |
Eravikulam, KL |
10.194811° |
77.077353° |
2243m |
|
11 |
Kallupaalam 2 |
Munnar Forest Division, KL |
10.190761° |
77.072839° |
2173m |
|
12 |
Bheemanoda 2 |
Eravikulam, KL |
10.196908° |
77.086600° |
2204m |
|
13 |
Bheemanoda 3 |
Eravikulam, KL |
10.192550° |
77.090950° |
2200m |
|
14 |
Varayattumala 1 |
Eravikulam, KL |
10.204817° |
77.085856° |
2212m |
|
15 |
Varayattumala 2 |
Eravikulam, KL |
10.208128° |
77.088392° |
2237m |
|
16 |
Kambipaalam Mala |
Eravikulam, KL |
10.217369° |
77.081100° |
2216m |
|
17 |
Eravikulam |
Eravikulam, KL |
10.209414° |
77.075336° |
2199m |
|
18 |
Eravikulam 2 |
Eravikulam, KL |
10.218831° |
77.078683° |
2178m |
|
19 |
Eravikulam 3 |
Eravikulam, KL |
10.221906° |
77.079378° |
2156m |
|
20 |
Sambamala Base |
Eravikulam, KL |
10.216506° |
77.071711° |
2200m |
|
21 |
Sambamala |
Eravikulam, KL |
10.213450° |
77.065103° |
2266m |
|
22 |
Anamudi View Near Kolukan |
Eravikulam, KL |
10.218089° |
77.059017° |
2229m |
|
23 |
Kolukkan |
Eravikulam, KL |
10.227481° |
77.047964° |
2110m |
|
24 |
Campamala |
Eravikulam, KL |
10.225033° |
77.074289° |
2329m |
|
25 |
Erumapetti |
Eravikulam, KL |
10.231128° |
77.089286° |
2269m |
|
26 |
Turners Valley |
Eravikulam, KL |
10.222319° |
77.089286° |
1901m |
|
27 |
Chinna Mannumudi |
Eravikulam, KL |
10.228486° |
77.094269° |
2247m |
|
28 |
Kudimala |
Eravikulam, KL |
10.215919° |
77.109719° |
2049m |
|
29 |
Near Varattukulam |
Eravikulam, KL |
10.236183° |
77.100469° |
2182m |
|
30 |
Kaatumala |
Eravikulam, KL |
10.254211° |
77.097894° |
2526m |
|
31 |
Kaatumala 1 |
Eravikulam, KL |
10.258489° |
77.101667° |
2271m |
|
32 |
Kaatumala 2 |
Eravikulam, KL |
10.267222° |
77.090308° |
2050m |
|
33 |
Poovar 1 |
Eravikulam, KL |
10.286419° |
77.084633° |
1984m |
|
34 |
Konalar |
Grass Hills, TN |
10.321906° |
77.070497° |
1896m |
|
35 |
Border Grass Hills |
Eravikulam, KL |
10.309903° |
77.092350° |
2096m |
|
36 |
Border Chinnar |
Eravikulam, KL |
10.299444° |
77.113611° |
2092m |
|
37 |
Poovar (Previous record) |
Eravikulam, KL |
10.273414° |
77.086064° |
2040m |
|
38 |
Anamudi (Previous record) |
Eravikulam, KL |
10.168367° |
77.059954° |
2695m |
KL—Kerala | TN—Tamil Nadu |
WS—Wildlife Sanctuary.
Table 2. Call characteristics of
141 calls of Raorchestes resplendens from 10 males.
|
Call character |
Mean |
SD |
Minimum |
Maximum |
|
Call duration (ms) |
103 |
37.3 |
58.9 |
148.8 |
|
Call rise time (ms) |
46.3 |
29.4 |
11.9 |
80.5 |
|
Call fall time (ms) |
56.7 |
16.8 |
39.9 |
69.8 |
|
Intercall interval (s) |
2.9 |
3.6 |
1.4 |
4.9 |
|
Overall dominant frequency (KHz) |
2.5 |
0.1 |
2.4 |
2.8 |
|
Call rate (calls/min) |
21.5 |
7.9 |
16.1 |
41.4 |
For
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References
Bachman, S., J. Moat, A.W. Hill,
J. de la Torre & B. Scott (2011): Supporting Red List
threat assessments with GeoCAT: geospatial conservation assessment tool. In: Smith
V, Penev L (Eds)
e-Infrastructures for data publishing in biodiversity science. ZooKeys 150: 117–126.
Bee, M.A., R. Suyesh
& S.D. Biju (2013a). The vocal
repertoire of Pseudophilautus kani, a shrub frog (Anura: Rhacophoridae) from the Western Ghats of India. Bioacoustics
22(1): 67–85. https://doi.org/10.1080/09524622.2012.712750
Bee, M.A., R. Suyesh
& S.D. Biju (2013b). Vocal behavior of the Ponmudi Bush Frog
(Raorchestes graminirupes):
repertoire and individual variation. Herpetologica
69(1): 22–35. https://doi.org/10.1655/HERPETOLOGICA-D-11-00042
Bhaskar, D., P.S. Easa, K.A. Sreejith, J. Skejo
& A. Hochkirch (2019). Large scale burning for a threatened ungulate in a
biodiversity hotspot is detrimental for grasshoppers (Orthoptera: Caelifera). Biodiversity and Conservation 28(12):
3221–3237. https://doi.org/10.1007/s10531-019-01816-6
Biju, S.D., Y. Shouche,
A. Dubois, S.K. Dutta & F. Bossuyt (2010). A ground-dwelling rhacophorid frog from the highest
mountain peak of the Western Ghats of India. Current Science 98(8):
1119–1125.
Frost, D.R. (2020). Amphibian Species of the World; an Online Rederence. Version 6.0 (accessed on 13 March 2020).
Electronic Database accessible at http://research.amnh.org/herpetology/amphibia/index.html.
American Museum of Natural History, New York, USA.
Halliday, T. (2006). Amphibians, pp. 278–293. In: Sutherland, W.J.
(ed.). Ecological census techniques: a handbook. Cambridge University
Press, Cambridge, 432pp.
Heyer, W.R., M.A. Donnelly, R.W. Mc Diarmid,
L-A.C. Hayek & M. Foster (1994). Measuring and Monitoring Biological Diversity
Methods for Amphibians. Smithsonian Institution Press, Washington D.C.,
690pp.
IUCN SSC Amphibian Specialist
Group (2011). Raorchestes resplendens. The
IUCN Red List of Threatened Species 2011: e.T189814A8772103. Downloaded on
12 April 2020. https://dx.doi.org/10.2305/IUCN.UK.2011-1.RLTS.T189814A8772103.en
IUCN (2012). IUCN Red List Categories and Criteria: Version 3.1.
Second edition. Gland, Switzerland and Cambridge,
IUCN, UK, iv+32pp.
IUCN (2016). Red List of Threatened Species. Version 2016.3.
Available from. www.iucnredlist.org, Accessed date 13 March 2020.
Joseph, J., K.M. Jobin & P.O. Nameer (2012). Additional record of Resplendent Bush Frog Raorchestes resplendens
(Anura: Rhacophoridae) from
the Western Ghats, India. Journal of Threatened Taxa 4(11):
3082–3084. https://doi.org/10.11609/JoTT.o3214.3082-4
Kanagavel, A., S. Parvathy, A.P. Chundakatil,
N. Dahanukar & B. Tapley (2018). Distribution and habitat associations of the
Critically Endangered frog Walkerana
phrynoderma (Anura: Ranixalidae),
with an assessment of potential threats, abundance, and morphology. Phyllomedusa: Journal of Herpetology 17(1):
21–37. https://doi.org/10.11606/issn.2316-9079.v17i1p21-37
Kerala Forests & Wildlife
Department (2013). Third
Management Plan of Eravikulam National Park. 2012–2013
to 2021–2022, 205pp.
Krishnamurthy, S.V. (2003). Amphibian assemblages in undisturbed and disturbed
areas of Kudremukh National Park, central Western
Ghats, India. Environmental Conservation 30(3): 274–282. https://doi.org/10.1017/S0376892903000274
Mittermeier, R.A., P.R. Gil, M.
Hoffmann, J. Pilgrim, T. Brooks, C.G. Mittermeier, J. Lamoreux,
G.A.B.D. Fonseca (2004). Hotspots
Revisited: Earth’s Biologically Richest and Most Endangered Terrestrial
Eco-regions. CEMEX, Mexico City.
Myers, N., R.A. Mittermeier, C.G.
Mittermeier, G.A.B.D. Fonseca & J. Kent. (2000). Bio-diversity hotspots for conservation priorities. Nature
403(6772): 853–858. https://doi.org/10.1038/35002501
Rajkumar, K.P., T.S. Prasad, S. Das, R. Sreehari,
P.S. Easa
& K.A. Sreejith (2016). New locality
Record of the Travancore Bush Frog Raorchestes
travancoricus Boulenger,
1891 (Amphibia: Anura: Rhacophoridae)
from Periyar Tiger Reserve, Kerala, India. Journal
of Threatened Taxa 8(1): 8379–8382. http://doi.org/10.11609/jott.2139.8.1.8379-8382
Tapley, B., C.J. Michaels, R.
Gumbs, M. Böhm, J. Luedtke, P. Pearce-Kelly &
J.J. Rowley (2018). The
disparity between species description and conservation assessment: a case study
in taxa with high rates of species discovery. Biological Conservation 220:
209–214. https://doi.org/10.1016/j.biocon.2018.01.022
Thomas, A., R. Suyesh,
S.D. Biju & M.A. Bee (2014).
Vocal behavior of the elusive purple frog of India (Nasikabatrachus sahyadrensis),
a fossorial species endemic to the Western Ghats. PloS
One 9(2): p.e84809. https://doi.org/10.1371/journal.pone.0084809
Vijayakumar, S.P., K.P. Dinesh,
M.V. Prabhu & K. Shanker
(2014). Lineage delimitation and
description of nine new species of bush frogs (Anura:
Raorchestes, Rhacophoridae)
from the Western Ghats Escarpment. Zootaxa
3893: 451–488. https://doi.org/10.11646/zootaxa.3893.4.1
Zachariah, A., V.P. Cyriac,
B. Chandramohan, B.R. Ansil,
J.K. Mathew, D.V. Raju, & R.K. Abraham (2016). Two new species of Raorchestes
(Anura: Rhacophoridae) from
the Silent Valley National Park in the Nilgiri Hills
of the Western Ghats, India. Salamandra 52(2):
63–76.