Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 February 2024 | 16(2): 24769–24774
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8749.16.2.24769-24774
#8749 | Received 21 September 2023 | Final received 06 January 2024 |
Finally accepted 21 January 2024
Erode Ground Gecko Cyrtodactylus speciosus
(Beddome, 1870) (Squamata: Gekkonidae)
from peri-urban common-lands of Coimbatore, India, with comments on habitat
associations
S.R. Ganesh 1, N.A. Swaathi 2 &
Usha Ravindra 3
1 Kalinga Foundation, Guddekere, Agumbe, Shivamogga,
Karnataka 577411, India.
2 Zoo Outreach Organisation
(Zooreach), 3A2 Varadharajulu
Nagar, FCI Road, Ganapathy, Coimbatore, Tamil Nadu 641006, India.
1 snakeranglerr@gmail.com
(corresponding author), 2 swaathi891@gmail.com, 3 usha@zooreach.org
Editor: Anonymity requested. Date of
publication: 26 February 2024 (online & print)
Citation:
Ganesh, S.R., N.A. Swaathi & U. Ravindra (2024). Erode Ground
Gecko Cyrtodactylus speciosus
(Beddome, 1870) (Squamata: Gekkonidae)
from peri-urban common-lands of Coimbatore, India, with comments on habitat
associations. Journal of Threatened Taxa 16(2): 24769–24774. https://doi.org/10.11609/jott.8749.16.2.24769-24774
Copyright: © Ganesh et al. 2024. 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: BOSCH.
Competing interests: The authors declare no competing interests.
Author details: Dr.
S.R. Ganesh is the director of research, Kalinga Foundation in Agumbe. He conducts research on reptiles and amphibians of southern India. His research themes include documenting the diversity of under-explored ecoregions, updating and refining species characterizations, and elucidating modern-day distribution patterns with respect to southern India’s herpetofauna. Ms. N.A. Swaathi, is a
budding biologist interested in reptiles. She interned under the wetland restoration project of Zoo Outreach Organisation, funded by BOSCH and is set to study and work more on reptiles, especially snakes. Ms.
Usha, Ravindra is a wildlife conservationist & researcher at Zoo Outreach Organisation, Tamil Nadu, India. As a part of their 1OCEAN project, she is trying to conserve bycatch species in marine fisheries. She is also assisting the South Asian Invertebrate Specialist Group (SAsISG) to conserve invertebrates.
Author contributions: All authors equally contributed in fieldwork, travel and data collection. NS and UR did data compilation and analysis under the supervision of SRG. SRG led the writing with inputs from NS and UR. All authors equally contributed to proofreading; and have read and approved the final file.
Acknowledgements: We thank BOSCH for funding this
study that is a part of wetland restoration project executed by Zoo Outreach
Organisation, Coimbatore. Thanks to Dr Sanjay Molur
for entrusting this work to us and for supporting and encouraging us. Thanks to
Priyanka Iyer, Pooja Patil,
and S. Sushanth for accompanying us during some of
the night surveys. SRG thanks Sanjay Molur, Ishan
Agarwal, and Achyuthan Srikanthan
for sharing details on the Erode Ground Gecko and the director, SACON and
officer-in-charge, ZSI Chennai for permitting specimen examinations at their
institutes. SRG is grateful to the founder director and trustees of the Kalinga
Foundation, Agumbe for encouraging his collaborative
research activities.
Abstract: We report the Erode Ground Gecko Cyrtodactylus speciosus
(Beddome, 1870), a rare, hill forest-dwelling
species, from two sites in the northern periphery of Coimbatore city. These two
sites, viz., Nallusamy checkdam
(Site–1) and Sarkar Sama Kulam
(Site–2) are lakes with remnant vegetation belts, surrounded by pastures,
farmlands, and villages. From 100 hours of observations during a six-month
period (April–September 2023) in these two sites, we report 14 sightings of C.
speciosus including gravid females, juveniles,
and subadults indicating a persistent breeding population. The encounter rate
estimates ranged from 5 h (in Nallusamy checkdam; n = 10/50 h) to 12½ h (in Sarkar Sama Kulam; n = 4/50 h),
averaging at about 7 h (pooled; n = 14/100 h) to get one sighting of C. speciosus. Our sightings of C. speciosus
in peri-urban common lands abutting a city, calls for intensified biodiversity
surveys and enhanced protections of such remnant vegetation belts, often
presumed to have low or marginalised conservation
values.
Keywords: Farmland, Nallusamy
checkdam, Sarkar Sama Kulam, Tamil Nadu, wetland.
Introduction
The Erode Ground Gecko Cyrtodactylus speciosus
(Beddome, 1870) is a species of nocturnal,
terrestrial, oviparous, gekkonid lizard endemic to parts of southern India (Beddome 1870; Agarwal et al. 2016, 2023a). It was first
described as Gymnodactylus speciosus based on the holotype BMNH 1946.9.4.88
(Natural History Museum, London) collected from “tope near Erode” (Beddome 1870). Then it was synonymised
with C. collegalensis (Beddome,
1870), another closely-related gecko that is morphologically similar and
geographically proximate to C. speciosus (see
Agarwal et al. 2016 and references therein). Agarwal et al. (2016) clarified
the afore-mentioned taxonomic complications in this group and also resurrected,
redescribed, and illustrated this poorly-known
species based on its partly damaged holotype. This species still remains unseen
from its stated type locality ‘Erode’ thus far, despite some surveys in hills
nearby (see Ganesh et al. 2018). Agarwal et al. (2016) allocated populations
from North Coimbatore Taluk (100 airline km south-west of the type locality,
‘Erode’) to C. speciosus. Agarwal et al.
(2023a) reported genetic similarity between populations from Coimbatore and Shevaroys (that are some 180 km apart, passing through
Erode; also see Ganesh & Arumugam 2016) and interchangeably represented C.
speciosus both with and without ‘cf.’ prefix,
indicating taxonomic uncertainty.
As for its distribution, the new
specimens of Agarwal et al. (2016) were from Maruthamalai
and Anaikatti hills, just to the north-west of
Coimbatore (Ishan Agarwal and N.S. Achyuthan pers.
comm. to SRG in April 2023). Agarwal et al. (2023a) reported a
genetically-similar population from Shevaroys – the
base of Yercaud near Salem. Our perusal of museum
registry and related data mining revealed C. speciosus
collections from North Coimbatore (CAS Herp 94157; California Academy of
Sciences, USA), Udumalpet (CAS Herp 91458), Aliyar (ZSI/SRS/VRL 156, unreg.;
Zoological Survey of India, Chennai), and Anaikatti
(SACON VR-5a-b; Salim Ali Centre for Ornithology & Natural History,
Coimbatore) (http://portal.vertnet.org/search?q=collegalensis; Ganesh et al.
2020; SRG unpub. Data). Taken together, populations
across potential barriers such as Cauvery River (Shevaroys)
and Palghat Gap (Aliyar, Udumalpet)
have been treated as C. speciosus. C. speciosus and a few other southern Indian congeners,
especially in the C. collegalensis complex
were reported to have a marked affinity to hilly forest terrains (Agarwal &
Karanth 2015). Agarwal et al. (2016) while remarking
on their excursions in Erode to re-sight topotypical C. speciosus
stated that Erode is a large town surrounded by agricultural matrix and that
their brief surveys did not yield findings of any Cyrtodactylus
or “suitable habitat” indicating that farmlands are not the ideal habitats for C.
speciosus. Murali (2023) reported C. cf.
speciosus from coastal plains of Thanjavur, again within unmanaged arid scrublands. In this
note, we report our findings of living populations of C. speciosus
sensu Agarwal et al. (2023a) in peri-urban
common-lands of Coimbatore.
Materials
& Methods
During April–September 2023, for
six months, as part of biodiversity assessment of degraded landscapes, we
conducted series of night surveys at two wetland sites in northern fringes of
Coimbatore. We sighted C. speciosus (Image 1)
in these sites, 3½ km apart, ear-marked for wetland restoration in peri-urban
north Coimbatore, viz., Site–1 Nallusamy checkdam (11.1103 °N, 76.9940 °E; 435 m elevation) in Keeranatham village and Site–2 Sarkar Sama
Kulam or SS Kulam for short
(11.1228 °N, 77.0216 °E; 420 m) in Kondayampalayam
village (Image 2), Coimbatore district, Tamil Nadu, India.
Results
From about 100 h of survey, we
obtained 14 sightings of C. speciosus of
varying sexes and maturity levels (Table 1), with an encounter rate of about 7
h survey to get 1 sighting, in these sites.
Site 1, Nallusamy
checkdam
On 8–9 April 2023, during
1830–0030 h (18 man h; 3 persons) visual encounter
survey a total of four sightings, including two gravid females (bulged belly,
absence of femoral pores, and hemipenal bulges), one
adult male (presence of femoral pores and hemipenal
bulges) and one unsexed (escaped before restraint) individual were documented.
The two gravid females were sighted at short distance (10 m away) and time (15
min. apart) intervals. When seen from below, two ova were visible through the
distended belly skin in both the female geckoes. On 30 May and 2 June 2023,
during 1900–2200 h (18 man h; 3 persons) visual
encounter surveys, no sightings of the gecko could be obtained. The area was
quite wet and slushy with many temporary rainwater puddles due to rains and the
survey time also experienced drizzles. On 2 and 3 August 2023, during 1945–2145
h (12 man h; 3 persons) visual encounter survey, six
sightings, including three unsexed subadults (organ under-developed), two
unsexed adults (escaped before restraint) and one unsexed juvenile (escaped
before restraint) were documented. In August, the geckoes were sighted on the
vegetated bunds of the ploughed lands. They were seen entering cracks and holes
in the ground upon our approach with spot-lights. Individuals were seen at the
base of shrubs and plants under the cover of the shrubby top layer. Subadults
were sighted in grassy patches. Juvenile was sighted in thick leaf-litter. On 2
September 2023, during 1915–2015 h (2 man h; 2
persons), no gecko of the target species was sighted. In Site–1, from 50 h
survey, 10 sightings were obtained, equating to 5 h survey to get 1 sighting of
C. speciosus.
Site 2, Sarkar Sama Kulam
On 29 May and 3 June 2023, during
1900–2200 h (18 man h; 3 persons) visual encounter
surveys, no sightings of the gecko was obtained. Due to rains, the area was wet
and partly inundated. On 4 August 2023, during 2100–2300 h (6
man h; 3 persons), two juveniles (distinctly small body size,
proportionally larger head and eyes, contrastingly coloured
body pattern patches), and one subadult (milder features of juveniles present)
were sighted. The area was dry lake bed with Acacia and Prosopis
trees and thorny scrub thickets close by. Sightings of the geckoes were on
small green herb patches of creeper-like plants growing in dried up waterbodies
and its fringes. Juveniles were faster in their locomotion, than the adults
seen. On all occasions, the young ones were aware of our presence and approach
and were scurrying away from us, trying to crawl into and hide into the ground
vegetation. On 5 August 2023, during 2000–0000 h (12 man
h; 3 persons), one subadult was sighted, in a similar area. On 6 August 2023,
during 2030–2330 h (6 man h; 2 persons), no gecko of
the target species was sighted. On 1 September 2023, during 1945–2345 h (12 man h; 3 persons), no gecko of the target species was
sighted. In Site–2, from 50 h survey, four sightings were obtained, equating to
12½ h survey to get one sighting of C. speciosus.
In both these sites, the general
habitat consisted of a mix of farmlands (of paddy and coconut trees), dried-up
lake with bund, open grasslands with thorny shrubs and sparse stony mounds. The
areas have alluvial soil and gravelly sand and were often interspersed with
garbage dumps, electric towers, tar roads, and fences. The surveyed sites were
water bodies that are either live (Site 1) or dried up (Site 2). On the sides of
the lake bunds there were open grounds, fallow lands, pastures, and farmlands.
On multiple occasions during the early evenings goats,
buffaloes, and cows were seen reared by local shepherds in both the sites. The
precise immediate microhabitats, i.e., the resting substrates of the geckos
were bare ground having sparse scrub, grass patches, debris of plant matter,
and gravel. The general area was a fallow land covered with low dense bushes
grown on and around muddy bunds, bordering agricultural fields. All the target
geckoes were seen active at night on ground of unploughed
patches bordering cultivated farmlands, across the bunds.
Syntopic gecko species sighted in both
the sites were Hemidactylus frenatus Schlegel, H. triedrus
(Daudin), H. leschenaultii
Dumeril & Bibron, H.
parvimaculatus Deraniyagala,
and H. cf. sankariensis Agarwal, Bauer,
Giri & Khandekar. From inaturalist we found that C. speciosus
has also been recorded in Ondipudur Weaver’s colony
(11.001044 °N 77.057633 °E), a southeastern suburb of Coimbatore (https://www.inaturalist.org/observations/94402766
accessed in September 2023). Upon a visit there, we found the habitat to be
similar to the ones at the surveyed sites 1 and 2. It was also learnt that C.
speciosus has been sighted in Ganapathy (11.0355
°N, 76.9790 °E) which today is a much more urbanized, core part of Coimbatore
city, during the early 1990s (Sanjay Molur pers.
comm. in April 2023). Coimbatore district includes parts of Siruvani
hills (>1,200 m) of the Western Ghats and the typical southern Indian plains
(here, at ≈400 m) with dry evergreen vegetation as the natural climax flora (Chandrabose 1981; Kiruthika et
al. 2017).
Discussion
We identified the geckoes as C.
speciosus following Agarwal et al. (2016) who
studied the Coimbatore population on both morphological and molecular lines.
This includes a caveat, as stated by Agarwal et al. (2016), that these are not
topotypical populations from the broad locality – Erode (also see Agarwal et
al. 2023a). The Coimbatore populations showed diagnostic features of C. speciosus sensu Agarwal et
al. (2016) and did not show any non-diagnostic features that potentially
resemble or overlap with regional, allopatric congeners (after Agarwal et al.
2023b). The Coimbatore geckoes exhibited two equidistant (rarely three) dark
transverse cross bars on trunk (vs. one in C. aravindi;
two much broader bars in C. rishivalleyensis;
irregular broken-up bars in C. srilekhae;
multiple series of large ovoid paired spots in C. collegalensis,
C. chengodumalaensis, C. irulaorum, C. relictus,
and C. varadgirii); uniform dorsal scalation
(vs. not so in C. nebulosus, C. jeyporensis,
and C. chengodumalaensis).
Agarwal et al. (2023) reported
that Coimbatore and Shevaroys populations of C. speciosus grouped together in their molecular
phylogenetic analysis. Additionally, Murali (2023) reported C. cf. speciosus from “unmanaged arid scrublands” within the
compounds of an old, stable, cattle breeding farm (estd.
1954, Govt. of Tamil Nadu) in Echankottai near Thanjavur, in the eastern coastal plains. This indicates
that this species (complex) also occurs in the plains of southern India. But
yet, despite surveys in the adjacent cashew and sugarcane fields, no Cyrtodactylus spp. were found (Murali 2023),
indicating its stenotopic nature. Seen against this
backdrop, our finding of C. speciosus in the
farmland precincts in the plains (400 m) opens possibilities for a probable
population contiguity between these degraded and distant (180 km) localities.
And the vital aspect of our
finding is the persistence of C. speciosus in
the mediocre remnant vegetation patches intermixed with anthropic land uses and
even human habitation. Unlike the commensally Hemidactylus
geckoes, C. speciosus being a strictly
terrestrial gecko, gets affected and displaced by habitat loss by building
construction. So it has been rightly assessed as an
endangered species (Achyuthan et al. 2021). Related
congeners were also reported to occur near cities, viz., C. collegalensis near Mysuru, C. srilekhae
near Bengaluru, C. chengodumalaensis near
Kozhikode, C. irulaorum near Chennai, and
C. varadgirii near Mumbai (Agarwal 2016; Agarwal
et al. 2016, 2023a,b).
Hence the presence of C. speciosus near Coimbatore is consistent with previous
such observations. Regarding other aspects of natural history, Guptha (1998) recorded this species (as Geckoella
collegalensis) based on an adult and a juvenile
seen on 11 October 1997 in the rocky outcrops of Anaikatti
slopes (600–700 m). In our case juveniles were seen somewhat earlier, in early
August, more or less coinciding with the reported observation (Guptha 1998). This indicates a breeding population of C.
speciosus in peri-urban common lands of
Coimbatore, warranting more such surveys in nearby places to accord greater
protection and scientifically-informed management to such remnant habitat
patches.
Table 1. Sightings of Cyrtodactylus speciosus
in the plains of peri-urban northern Coimbatore; left columns Site-1 (Nallusamy checkdam); right columns
Site-2 (Sarkar Sama Kulam);
#-gravid; *-adults.
|
Months |
Survey (man h) |
Males* |
Females* |
Unsexed* |
Subadults |
Juveniles |
Total no. |
|||||||
|
April |
18 |
0 |
1 |
0 |
2# |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
4 |
0 |
|
May–June |
18 |
18 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
August |
12 |
20 |
0 |
0 |
0 |
0 |
3 |
0 |
2 |
2 |
1 |
2 |
6 |
4 |
|
September |
2 |
12 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Total |
50 |
50 |
1 |
0 |
2 |
0 |
4 |
0 |
2 |
2 |
1 |
2 |
10 |
4 |
For
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