Activity pattern of
Sloth Bear Melursus ursinus (Mammalia: Ursidae) in Mudumalai Tiger
Reserve, Western Ghats, India
Tharmalingam Ramesh 1, Riddhika Kalle 2, Kalyanasundaram Sankar 3& Qamar Qureshi 4
1–4 Wildlife Institute of India,
P.O Box # 18, Chandrabani, Dehradun, Uttarakhand 248001, India
1 ramesh81ngl@gmail.com
(corresponding author), 2 riddhikalle@gmail.com,
3 sankark@wii.gov.in, 4 qnq@wii.gov.in
doi: http://dx.doi.org/10.11609/JoTT.o3071.3989-92 | ZooBank: urn:lsid:zoobank.org:pub:2EA70CAD-5375-4D56-8DC8-07A8B89D48D9
Editor: Mewa Singh,
Mysore University, Mysore, India Date of publication: 26
March 2013 (online & print)
Manuscript details: Ms #
o3071 | Received 18 January 2012 | Final received 29 December 2012 | Finally
accepted 21 February 2013
Citation: Ramesh, T., R. Kalle, K. Sankar & Q. Qureshi (2013).Activity pattern of Sloth Bear Melursus ursinus (Mammalia: Ursidae)
in Mudumalai Tiger Reserve, Western Ghats, India. Journal of Threatened Taxa 5(5): 3989–3992; doi:10.11609/JoTT.o3071.3989-92.
Copyright: © Ramesh et al. 2013. Creative Commons Attribution 3.0 UnportedLicense. JoTT allows unrestricted use of this
article in any medium, reproduction and distribution by providing adequate
credit to the authors and the source of publication.
Funding: This research was undertaken as
part of “Sympatric carnivore studies,” funded by Wildlife Institute of India.
Competing Interest: None.
Acknowledgements: We
thank the Director and Dean, Wildlife Institute of India and the Chief Wildlife
Warden, Tamil Nadu for granting permission to work in Mudumalai.
We would also like to thank our field assistants C. James, M. Kethan, M. Mathan and forest
department staff for their assistance and support during field
work.
The publication of this article is
supported by the Critical Ecosystem Partnership Fund (CEPF), a joint initiative
of l’Agence Française de Développement, Conservation International, the
European Commission, the Global Environment Facility, the Government of
Japan, the MacArthur Foundation and the World Bank.
Activity patterns are shaped
largely by the biological requirements of a species (Wrangham& Rubenstein 1986). Activity patterns in mammals can be influenced by foraging, prey behaviour, predator avoidance, physiological traits,
vegetation cover and climate (Seidensticker1976). The activity patterns of Sloth
Bears have been described based on radio-collared individuals (Joshi et al.
1995, 1999; Yoganand et al. 2005; Ratnayekeet al. 2007), den site observations and indirect evidences (Baskaran1990; Desai et al. 1997; Akhtar et al. 2004; Chauhan et al. 2004). Sloth Bears are known to be nocturnal and crepuscular in activity (Chauhan et al. 2004; Yoganand et
al. 2005). The protected areas of
deciduous forests hold large forest tracts and contiguous forests that support
a considerable population of Sloth Bear while in other forest types,
populations mostly occur in low abundance in India (Yoganandet al. 2006). The Western Ghats
range is one of the strongholds of Sloth Bear distribution, in terms of both
population abundance and habitat availability in India (Yoganandet al. 2006). Mudumalaiis one of the few tropical forests in the Western Ghats where the Sloth Bear is
widely distributed (Desai et al. 1997; Ramesh et al. 2010, 2012) and thrives in
dense forest areas (Yoganand et al. 2006). Camera trapping provides valuable
ecological information on these species and has its own advantage that includes
capture of more number of individuals at a spatial scale
which is a limitation in radio-collared studies (Ramesh 2010). However, use of information from systematic
camera trapping surveys to study activity patterns remains rare (Gopalaswamy 2006). Here we used camera trapping technique as a
useful tool to study activity patterns of Sloth Bears.
Materials and Methods: Mudumalai Tiger Reserve (11032’–11043’N
& 76022’–76045’E) is situated at the
tri-junction of the southern Indian states of Tamil Nadu, Karnataka and Kerala
at an elevation that varies from 960–1,266 m. This 321km2reserve is bound by Wayanad Wildlife Sanctuaryon the west, Bandipur Tiger Reserve in the north, and
in the south and east by Sigur and Singara forest divisions. The vegetation types found in Mudumalai are classified into southern tropical dry thorn
forest, southern tropical dry deciduous forest, southern tropical moist
deciduous forest, southern tropical semi-evergreen forest, moist bamboo brakes
and riparian forest (Champion & Seth 1968). The terrain is gently undulating. It receives rainfall from both the south-west monsoon between May and August and the north-east
monsoon between September and December. Three distinct seasons are recognized; dry season (January–April),
first wet season (May–August) and second wet season
(September–December) (Varman & Sukumar 1993). The rainfall has a marked east-west gradient, with the areas in the east
getting the least amount of the heavy rains (1000–2000 mm). The mean temperature ranges from
15.7–28.7 0C between November and April. Other large carnivores found in the
Reserve are Tiger Panthera tigris, Leopard Panthera pardus and Dhole Cuon alpinus.
Camera traps were deployed
(November 2009 to April 2010) as part of the research on sympatric large
carnivores—Tiger, Leopard and Dhole—within an intensive study area
of 187km2 covering deciduous forest (DD), semi-evergreen forest (SE)
and dry thorn forest (DT) of Mudumalai Tiger Reserve
(Fig. 1). Cameras were deployed
systematically in stations that maintained an average inter-station distance of
1.8km to cover the study sites without leaving any large space in the trap
array for Tiger, Leopard and Dhole. However, Sloth Bears are known to have home ranges of even more than
30km2 (Yoganand et al. 2005) and we
believe that this spacing will allow inclusion of many spatially distributed
unique individual Sloth Bears in the study area. The camera stations were placed on
roads, trails, stream-beds or near water holes to
maximize bear photo captures. According to the available extent of the major forest types, we set up
20 trap stations for 70 days in deciduous habitat, and 17 and 13 trap stations
for 40 days in semi-evergreen and dry thorn forest respectively on a 24hr
basis. Each station comprised of
two pairs of passive infrared cameras to maximize Sloth Bear captureprobability. Cameras were loaded with 36-print, 200 American Standard
Association (ASA) 35mm film. The
event of capturing an individual Sloth Bear, photographed by single or both
camera traps, was considered to be an independent record of that species based
on time and trap location. Both
sides of an individual animal and duplicate photographs of the same animals
were taken during a short period of time (<30 seconds) however, only one
photo was considered as an independent photo for further analysis. The percentage of activity level was used
to indicate whether the study species was nocturnal or diurnal. Time of capture was used to create 24-hr
activity patterns of Sloth Bear. Photographs provided information on the date
and time of the picture taken and were used to establish the activity pattern
of Sloth Bear. Photographs were sorted out into two hourtime intervals to examine activity pattern. The mean activity of Sloth Bear was
quantified by Watson’s U2 test using program Oriana3.21 (Kovach 2009).
Results: Totally, 61 independent
photographs were obtained from 2600 trap nights. Sloth Bears showed bimodal peaks in
their activity; the first peak was observed from late evening to midnight and
another small peak in the early morning during sunrise. Though Sloth Bears were active
throughout the day they exhibited reduced activity during the hottest hours of
the day (Fig. 2). The mean activity
time was 21:54±00:46 hrs (95% CI 20:23–23:25,
Watson’s U2 test, p<0.01).
Discussion: Several authors observed that
though Sloth Bears were active throughout the day, they were mostly nocturnal
and crepuscular (Chauhan et al. 2004; Yoganand et al. 2005) and active during the evening and
night (Joshi et al. 1999). In the
present study, Sloth Bears showed more activity during late evening to
midnight, and early mornings. They
were less active during the mid day. Sloth Bears may have reduced their activity during the day to avoid the
intense heat. Day-resting habits by
Sloth Bears have been reported from long-term radio-telemetry studies in Panna National Park where bears were observed resting in
dense undergrowths, often in gaps between large
boulders and inside caves during intense heat in the dry season (Yoganand et al. 2005). Similar habits of Sloth Bear may prevail in Mudumalai which may have
resulted in their low captures during mid-day (11–15 hr). However, activity pattern may vary
depending on geographical location, climate, distribution of food resources, interaction with other species, human disturbance and other factors(Yoganand et al. 2005). Some of the differences observed in
activity patterns among sites could result from different methodologies used to
study the species. Camera trapping has
proved to be a useful complement to telemetry study in documenting 24hr
temporal activity pattern of Sloth Bear. Camera trapping can augment the
details of spatio-temporal patterns of multiple
individuals simultaneously with less effort than telemetry study. Our data demonstrate that use of
camera-traps in documenting activity patterns can be an effective tool for
identifying biological questions in depth to document Sloth Bear ecology for
future studies.
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