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53
Journal of Bioresources 3(1): 53-59 (2016)
ISSN 2394-4315
Original Research Article
Habitat Preference Of Tokay Gecko (Gekko gecko) In Barak Valley
Of Assam, India
Biswajit Singh and P. Choudhury*
Department of Ecology and Environmental Science, Assam University, Silchar -788011, India
*Corresponding author: parthankar@rediffmail.com
Received: November 15, 2015; revised: May 5, 2016; accepted: May 13, 2016
Abstract : Study of habitat characteristics and distribution pattern of Tokay Gecko (
Gekko gecko
) was carried out in Barak
valley of southern Assam by transect method. 112 individuals were recorded during the study period. Out of which, highest
individuals were found in Irongamara of Cachar district. In the study area, the average encounter rate was 6.92/km.
Gekko
gecko
is distributed thoughout the Barak valley. In addition, it was found in houses like mud house, pucca house and RCC
buildings, irrespective of trees which is its natural habitat. Mud house as their most preferred habitat as they were mostly
found perching on the mud walls, individuals were found perching at medium level height i.e., 2m above the ground . Trees
with good canopy cover are their other suitable habitat. Among plants, the species was more abundant in
Ficus
sp. due to
moderately high temperature and moderate moisture inhabiting in the hole. Most of the calls were given during evening
hours, which is the peak hour for feeding by clinching on the outside wall of the house at night. The species mainly feed on the
insects. Cockroach, moth and spider are recorded as their favourite prey. The local village men have a social taboo for the
species and it is believed that it occurrence in houses bring ‘good fortune’ for the family. Of late, severe illegal trading of the
animal has brought about drastic decline of the species from the study area.
Key words: Assam, Conservation,
Ficus
sp., Gecko, Herpetofauna, Mud house
Introduction
Tokay Gecko is an Old World species (Wilson and Porras,
1983; Meshaka, 2011) and second largest extant Gecko species
(Manthey and Grossmann, 1997), second only to the skinks
(Pough
et al
., 2001). Males are generally larger than females.
The body is blue-mauve, along with scattered small red and
orange spots on the body (Meshaka, 2011). The skin is warty
in texture and characteristic territorial vocalisation which gives
rise to the Tokay Gecko’s colloquial name in English (“to-
kay”) (Das, 2010). It is variously known as “Ko-ko”, “to-to”,
“thok-kok” or “ko-kok shap” in Barak valley. The vocalisation
is uttered in a loud, barking crescendo and can be heard
from several metres away.
Tokay Gecko is distributed in South-east Asia
(Peninsular Malaysia, the Philippines, Singapore, Thailand,
Vietnam Cambodia and Indonesia (excluding territory in
Borneo and New Guinea), north eastern India, Southern
China, Hong Kong (special administrative region (SAR) and
Nepal (Das, 2010; Caillabet, 2013). Tokay Geckos have also
been introduced to Belize (Meerman and Garel, 2005), the
Lesser Antilles (Powell and Henderson, 2005), Madagascar
(Lever, 2003), Martinique (Henderson
et al
., 1993), Southern
Brazil (Junior
et al.,
2015) and the United States of America
(Hawaii and Florida) (Lever, 2003; Meshaka, 2011). In India,
it is mostly distributed in north eastern states of Assam (Das
et al
., 2009), Mizoram (Lalrinchhana and Solanki, 2015),
Tripura (Majumdar
et al.,
2012).
They are arboreal and can be found in lowland and
sub-montane primary and secondary forests as well as heavily
54
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
modified human landscapes (Manthey and Grossmann, 1997).
The species is nocturnal, feeding chiefly on moths,
grasshoppers, beetles, termites, crickets, cockroaches,
mosquitoes and spiders (Das, 2010). This species has also
been known to prey on other geckos, small rats and mice
and snakes (Love, 2000; Meshaka
et al
., 2004; Das, 2010). The
study was designed to throw light on the habitat preference
of the species. As the species is mostly arborial but during the
past few years it has been found to shift to human habitation
(Meshaka
et al
., 2004). This compelling situation has lead us
to know the reason behind it’s shift of habitat.
Materials and methods
Study area
The study of Tokay Gecko (
Gekko gecko
) was carried in selected
villages of Dargakona Hills in Barak valley of southern Assam,
where it is abundantly found. The Dargakona Hills is situated
at the low spurs of Inner Line Reserve Forest (ILRF) of Barak
valley. The area had dense forest represented by tropical semi
evergreen type (Dutta
et al.
, 2008). The climate of the study
area is sub-tropical warm and humid with average rainfall of
2700 - 2800 mm, most of which is received from the northeast
monsoon during May to September. The mean maximum
temperature ranges from 25°C to 38°C during July-August, while
the minimum is about 10°C during December and January
.
The vegetation in the area is dominated by
Artocarpus chama
and
Tetrameles nudiflora
in the top canopy layer,
Ficus
spp.
and
Artocarpus lacucha
in the middle layer and the lower layer
is dominated by
Shizostachyum dulooa
, saplings of
Goniothalamus
sp.,
Cyclostemon
sp.,
Mimosa himalayana
etc.
Th e un der growth is dominated by
Desmodium trifolium
, saplings
of
Calamus guruba
,
Daemonorops
sp.,
Homalonema
sp. and
seedlings of
Artocarpus chama
. Disturbance in the area has
resulted in the growth of some early successional and invasive
species like
Mikenia mikrantha
,
Eupatorium odoratum
,
Ageratum conyzoides
,
Combretum
sp
., Desmodium trifolium
,
Borreria hispida
,
Melastoma
sp
.
and
Mimosa pudica
. Grass
species like
Chrysopogon
sp. and
Saccharum
spp. are also
present along with scattered presence of plants like
Pandanus
sp. and
Licuala
sp. (Dutta
et al
., 2008).
The area is home to an impressive array of animals ranging
from microscopic zooplanktons to some endemic primate
species like the Spectacle monkey, Western Hoolock Gibbon
and the white lipped pit viper. Some sympatric species of
Gekkonidae family are also found in this region such as
Assamese Day Gecko (
Cnemaspis assamensis
), Flat- tailed
Gecko (
Cosymbotus platyurus
), Khasi Hill Bent-toed Gecko
(
Cytodactylus khasiiensis
), Tokay Gecko (
Gekko gecko
) and
Asian House Gecko (
Hemidactylus frenatus
) (Dutta
et al.,
2008).
The study was carried out at certain villages viz.
“Irongmara” and “Borojalenga”, the adjoining villages of the
Assam University premises as the marker point. Irongmara
is located 13.5 km away from Silchar, the district headquarter
of Cachar district and 2 km away from the University. The
area has an altitude of 50-58 meter above the MSL and falls
under latitude of 24°41
'
51´´ and 24°46
'
13´´
N and longitude
of 92°44
'
87´´
and 92°55
'
62´´ E. “Dargakona” is situated
adjacent Assam University, Silchar campus. It is located one
km away from the Assam University campus and lies between
latitude of 24°41
'
34´´ N and longitude of 92°45
'
33´´ E. The
Hills of Dargakona is in the close vicinity of numerous villages
and also the Silcorie tea estate. It is also situated adjacent to
the Chatla beel area of Cachar District (Dutta
et al.,
2008).
“Borojalenga Part-I” is an area located around 5 km away
from the Assam University Campus and lie between 24°40
'
14´´
N latitude and 92°43
'
46´´
E longitude. The area has secondary
vegetation and is having human habitations. It is also a part
of the Borojalenga Tea Estate. The area has good diversity of
avian fauna. Another study area named, “Dwarbond Grant”
is situated around 8 km away from the Assam University
campus, Silchar and lies between latitude of 24°37
'
52´´
N and
longitude of 92°42
'
32´´ E. This area also has secondary
vegetation and is surrounded by some monoculture areas
(tea garden). The road near Dwarbond is the connective link
between the two adjoining districts (i.e. Silchar and Hailakandi)
and the road leads to the neighbouring state, Mizoram.
Another study area, “Iringmara” is located around
9 km away from Assam University, Silchar campus of Assam.
55
It lies between 24°37
'
34´´ N latitude and 92°41
'
37´´
E
longitude. It is a small village surrounded by hills and tea
Estate. It has a moderate weather with both semi-tropical
and secondary forest. “Nakshatila” is another study area
situated around 15 km away from the Assam University
campus and lie between latitude of 24°33
'
44´´ N and longitude
of 92°44´ 8´´
E. It is a small village adjacent to the Inner Line
reserve forest and thus it has a characteristic of the dense
forest near by the area. It has many lakes and ponds too.
The area has many bamboo clump and dense cover of tall
trees. Since the area is adjoining to Inner Line Reserve Forest,
has high diversity of both flora and fauna. Most of these
adjoining villages are located within Inner Line Reserve Forest
Area, while some are situated in the fringe areas.
Sur vey
The study was carried out by line transect method (Singh
et al.,
2006), considering each transect of 1 km area. A total of
14 transects were taken, i.e., 3 transects in Assam University
campus, 6 transects in Irongmara, 1 transect each in
Dargakona, Borojalenga, Dwarbond Grant, Iringmara and
Nakshatila (Fig. 1). Initially, a pilot survey was done to measure
the area and to know the trail. Presuming there is no presence
of the species, information from people were collected and
subsequently the species were searched extensively. Both direct
and indirect sighting (call record) were used to count the
number of individuals for each transect. As Tokay Gecko is a
nocturnal species, so in addition to the survey during day
hours, night time survey was also conducted at desired places
for 3-4 consecutive. During field study the equipment’s like
GPS, Data Sheets, high power charging light and torch light
etc. were used.
Habitat analysis was done to measure the different
characteristic of the habitat through data sheets. Parameters
like as perching height (Loos
et al.,
2012) was taken into
account. Equipments like Lux meter, measuring tape and
thermometer were used.
Questionnaire survey was initially conducted for
understanding availability of the species and later on to know
the level of threats, so that need based, remedial conservation
measures could be taken.
The data was collected from February, 2014 to April,
2014. Due to the seclusive nature of Tokay Gecko and absence
of their call in the month of February, extensive survey was
done during March and April, 2014. Data sheets were prepared
to collect all the required field information like locality, date,
time, GPS points, microhabitat characteristics like,
Fig. 1. Study area map of Barak valley (Cachar, Karimganj and Hailakandi) showing the
location of study sites (on a satellite image from Google earth).
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
Table 1. Showing the number of transects, number of individuals found in different
study area and its sex ratio. A total of 14 transects were taken with respect to their area
size. Highest individuals were recorded in Irongmara.
Assam University, Silchar 3 29 1 17 11
Irongm ara 6 59 7 13 20
Dargakona 1 5 1 4 0
Borojalenga 1 7 1 3 3
Duarbond Grant 1 3 0 2 4
Iringmara 1 4 0 3 0
Nakshatila 1 5 1 2 1
Study area Number of
Transects
Number of
Individuals
Sex ratio
Male female unknown
56
temperature, humidity etc. of each individuals was recorded.
Collection of data were done by transects as well as
questionnaire survey in the villages on presence of Gecko
with subsequent record in the data sheets. Acoustic searching
was also done; individual animal, wherever seen, were
photographed. Call sound was recorded using Samsung Galaxy
Fit and Micromax Canvas audio recorder whenever possible.
Data was analysed to find out the encounter rates and density
of the species. Identification of Tokay Gecko was done using
different field guide (Ahmed
et al
., 2009; Das, 2010)
Results
Total number of individuals found throughout the study in
all transect is 112 (Table 1). Their density was found to be
more in Assam University Campus followed by Borojalenga.
Encounter rate was found to 6.92/km (Table 2). Tokay Gecko
is distributed throughout this region and is comparatively more
abundant in village areas.
Tokay Gecko was found in different type of house (mud
house, pucca house and RCC building). Among all these, their
most preferred habitat was found to be mud house followed
by RCC building (Fig. 2). Household areas were their
preferred habitat preference than tree. In the village areas, it
was found in the mud houses and trees. In the villages it is
mostly found in mud houses due to availability of better
Fig. 2. Preference of habitat amongst different habitat. Gekko gecko were found both
in houses and tree. Among houses, most numbers of individuals were recorded in mud
house.
microhabitat as required by the species. Mud house provides
moderate temperature (~32.13°C) and humidity (~58.30%)
and have high chance of food availability as many insect species
occur in this type of houses.
Tokay Gecko was found to perch on place like walls, roof
and tree holes and were mostly found to perch on the walls.
The average perching height in houses was found to be 2.14m
with the lowest perching height as 0.41m and the highest
perching area as 3.67m (Fig. 3). During the study it was found
that the ratio of female is more as compared to that of male
(Table. 1). Some of the individuals could not be enumerated
as they were counted through call count. However, in such
cases the number was considered as one. Tokay Gecko was
also found in RCC buildings and
‘pucca’
houses in Assam
University and also on trees in the Assam University premises.
Table 2. Number of individuals and population density of
Gekko gecko in
each
studied area. The population density was found highest in Irongmara followed by Assam
University, Silchar. The overall population density was found to be 6.92/km
Assam University, Silchar 29 4.83
Irongmara 59 19.66
Dargakona 5 5
Borojalenga 7 7
Duarbond Grant 3 3
Iringmara 4 4
Nakshatila 5 5
112 6.9 2
Studied area Number of
Individuals
Population
Density (n/Km)
Fig. 3. Percentage of perching height of the
Gekko gecko.
Here, the variable is height
and the levels were categorized as Low: 1m above the ground; Medium: 2m above the
ground; High: 3m above the ground .
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
57
Fig. 4. Number of individual with respect to temperature and humidity. The individuels
were found to be high with moderately high temperature and moderate humidity i.e., 8
individuals were found at ~36°C temperature and at ~60% humidity.
A total of 7 tree species were recorded where Tokay Gecko
was found to occur. It was mostly found in the
Ficus religiosa
followed by other
Ficus
sp. and
Artocarpus
sp. The
temperature was found highest and humidity was found to
be lowest in the
Ficus
sp. which means that Tokay Gecko is
most significantly found in trees with high temperature and
moderate humidity (Fig. 4). The basal is highest for
Ficus
Sp.
has a significant relation to its abundance in this tree. Thus,
the individuals were mostly found to occur in
Ficus religiosa.
It was also found in
Artocarpus
sp. due to its high canopy
cover. In tree, the perching height of individuals were found
to be highest to 13.7 m on
Gmelina arborea
due to presence
of tree hole at great height. The phenophase of the tree were
also recorded and was found that they tree were in their
stage of high leave cover in
Ficus
sp. and reproductive phase
was also recorded with flowering and fruiting stage in
Mangifera indica
and
Tamarindus indica.
Habitat preferences
of this reptilian species is presented in Fig. 5(A-D).
The advertisement calls was recorded throughout
the day and it was found that in morning period it gives most
calls at 8 am to 9 am and in the evening period it gives most
calls in between 9 pm to 10 pm. They frequency of calls was
found to be highest in the evening.
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
Fig. 5 . Habitat preferences of Tokay Gecko : (A) Ceilings and walls of RCC house, (B) Crevices of mud house, (C) Holes and crevices of trees, (D) Capturing preys (insects) at
night on walls of house.
58
Discussion
The study area is located in a forest fringe and harboured a
good number of Tokay Gecko population. Comparatively
more population in the Assam University areas may be due
to its vegetation types and the good level of protection. The
area earlier had dense forest represented by tropical semi
evergreen type (Dutta
et al.,
2008) due to the species is still
found in some segments of the university. Tokay Gecko was
found mostly in the abandoned buildings of the university
where zero level disturbances are there. It is also found in
good number in other houses with human population, where
they might migrated from the adjacent forest areas. Among
the adjoining villages, Tokay Gecko was found mostly in
Irongmara due to habitat suitability. The reason may be that
the village area has a good primary food than the Assam
University which is a secondary forest area. All other study
sites reveal almost similar type of distribution patterns of
Tokay Gecko population. The species is widely distributed in
Barak valley from dense forest to even occupying the space
within Institutional area and human habitat in general.
This may be that it perching height give more safety
from the human if it is higher than its possible enemy. During
the present study, most of the Gecko were observed at outdoor
during night hours. Tokay Gecko was found outdoor then
indoor at night. The reason may obviously be attributed to
the nocturnal habit of the species, as during night they come
out for feeding on their prey.
Habitat alteration is a big problem for the survival
of the species as they prefer to live on trees with high basal
area and canopy cover, but due to continuous decrease in the
no. of such trees, they shift to human habitation. With the
increase in the urbanisation, the mud house are also converted
to pucca house and RCC buildings which give less chance of
survival. Deforestation and conversion of primary forest into
secondary plays a major threat. Cutting of large canopy
covering trees are also affecting its population.
As mentioned, most of the calls were given during
evening hours, which is the peak hour for feeding on prey
mostly insects, clinching on the outside wall of the house at
night. As Tokay Gecko is mostly an insectivores and the study
shows that feed on different insects, mostly the cockroach
and spiders and other insects. It prefers to stay in the wall to
prey the insect.
Conservation initiative is the urgent necessity, as of
late, the species has become a subject of special attention for
the illegal traders. The use of reptile body parts (fat, skull,
bone, organs and blood) is very specific for fetish practices, as
each body part is considered to be essential in traditional
pharmacopoeia for various diseases (e.g., convulsions, malaria,
fever, HIV-AIDS, liver problems, tetanus, induce vomiting,
etc.)
(SeGniaGbeto
et al.,
2013).
Till date, Tokay Gecko is given less important from
the conservation point of view. The species is not being listed
in International Organization like in IUCN; not even listed as
data deficient. In CITES there is a proposal to put Gecko in
its Appendix but still it is not evaluated. Recently in India,
there is an amendment in Wildlife (Protection) Act, 1972 and
under this amendment the
Gekko gecko
is enlisted under
schedule IV. Such negligence in the policy making decision
has become one of the grey areas for conservation of the
species. It is apprehended that if immediate attention is not
given to the species, it is quite likely that the species will soon
come under the endangered category.
Although, the local people have a social taboo that
its presence is good for the health, wealth and welfare for the
family, which is a good conservation indication from
conservation point of view. Our study give us an information
that mud house provide a good habitat for the species. So,
people must be encouraged about the value of this kind of
housing. Some conservation initiative could be taken like giving
incentives to those people who have Gecko in their house so
that they get encouragement to protect the species. People
must be educated and make aware about the important of
this species. Since, it is a first kind of work to know the habitat
preference of the species, we encourage for more such work
in future in broader context.
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
59
Biswajit Singh and P. Choudhury., 2016 Habitat preference of Tokay Gecko
Acknowledgments
The authors are thankful to the Head of the Department Dr.
Jayashree Rout for her kind support. Authors also thankful to
all security staff of the University and all the village people with
their valuable information and kind Cooperation. The first author
also acknowledges the support extended by Dr. M. Dey, Dr. H.
J. Singha, Piyali Acharjee, Sumit Nath, Sunny Roy, Samir Das,
Priti Gupta, Dipankar Debnath, Samrat Sengupta and
Manabenandra Roy Choudhury of the Department of Ecology
and Environmental Science, Assam University.
References
Ahmed, M.F., Das, A. and Dutta, S.K. 2009.
Amphibians and reptiles of north east India- a photographic
guide. Aaranyak, India. Pp: 63.
Caillabet, O. 2013. The trade in Tokay Geckos in south-
east Asia: with a case study on novel medicinal claims in
Peninsular Malaysia. Pp: 2-3. Available online at: http://
www.traffic.org/home/2013/4/11/aids-cure-rumours-short-
lived-tokay-geckos-mainly-traded-for.html
Das, A., Saikia, U., Murthy, B.H.C.K., Dey, S. and
Dutta, S.K. 2009. A herpetofaunal inventory of Barail
Wildlife Sanctuary and adjacent regions, Assam, north-eastern
India. Hamadryad. 34(1): 117-134.
Das, I. 2010. A field guide to the reptiles of south-east Asia.
New Holland Publishers, London. Pp: 218.
Dutta, B.K., Gupta, A., Das, A.K. and De, A. 2008.
Ecology and biodiversity of Assam University campus.
Department of Ecology & Environmental Science, Assam
University, Silchar. Pp: 33.
Henderson, R.W., De Latte, A. and McCarthy, T.J. 1993.
Gekko gecko (Sauria: Gekkonidae) established on Martinique,
French West Indies. Caribbean Journal of Science.
29: 128-129.
Junior, J.C.R., Piva, A., Batista, J. and Machado,
C.D. 2015. Occurrence of the Tokay Gecko Gekko gecko
(Linnaeus 1758) (Squamata, Gekkonidae), an exotic species
in southern Brazil. Herpetology Notes. 8: 8-10.
Lalrinchhana, C. and Solanki, G.S. 2015. Lizard
(Reptilia: Sauria) diversity of Dampa Tiger Reserve, Mizoram,
India. Science Vision. 15(1): 19-28.
Lever, C. 2003. Naturalized reptiles and amphibians of the
world, 1st ed., Oxford University Press, USA. Pp: 77.
Loos, J., Wehrden, H.V., Dang, K.N. and Ziegler, T.
2012.
Niche segregation in microhabitat use of three sympatric
cyrtodactylus
in the phong nha-ke bang National Park, Central
Vietnam. Herpetological Conservation and Biology. 7(1): 101-108.
Love, W.B. 2000. Gekko gecko (Tokay Gecko). Predation.
Herpetological Review. 31: Pp 174.
Majumdar, J., Bhattacharjee, P.P., Majumdar, K.,
Debnath, C. and Agarwala, K. 2012. Documentation of
the herpetofaunal species rischness in Tripura, northeast India.
NeBIO. 3(1): 60-70.
Manthey, U. and Grossmann, W. 1997. Amphibian
and Reptilien Südostasiens. Natur und Tier-Verlag, Münster,
Germany. Pp: 512.
Meerman, J. and Garel, J. 2005. Tokay Gecko Gekko
gecko. (L) established on South Water Caye, Belize. Available
online at: http://biological-diversity.info/tokay.htm
Meshaka, W.E. Jr. 2011. A Runaway Train in the Making:
The Exotic Amphibians, Reptiles, Turtles, and Crocodilians
of Florida. Monograph 1. Herpetological Conservation and
Biology. 6: 1-101.
Meshaka, W.E. Jr., Butterfield, B.P. and Hauge, J.B.
2004. The Exotic Amphibians and Reptiles of Florida. Krieger
Publishing, Company. Malabar, Florida, USA. Pp: 166.
Powell, R. and Henderson, R.W. 2005. Conservation
status of lesser Antillean reptiles. Iguana. 12 (2): 63-78.
SeGniaGbeto, G.H., Petrozzi, F., Aïdam, A. and
luiSelli, L. 2013. Reptiles traded in the Fetish market of
lomé, togo (West Africa). Herpetological Conservation and
Biology. 8(2): 400-408.
Singh, J.S., Singh, S.P. and Gupta, S.R. 2006. Ecology,
environment and resource conservation. Anamaya Publishers,
New Delhi. Pp: 199.
Wilson, L.D. and Porras, L. 1983. The ecological impact
of man on the south Florida herpetofauna. University of
Kansas Museum of Natural History, Special Publication No.
9, Lawrence, Kansas, USA. Pp: 89.