Feeding ecology of sloth bears in a disturbed area in central India
H.S. Bargali"4, Naim Akhtar2'5, and N.P.S. Chauhan3'6
1WorldWideFund for Nature-India, LodiEstate, New Delhi 110003, India
2WildlifeTrustof India,C-644, New FriendsColony,New Delhi-65,India
3WildlifeInstituteof India,P.O. Box 18, Chandrabani,Dehradun248001, India
Abstract: In CentralIndia,the NorthBilaspurForestDivision (NBFD) harborsa largenumberof sloth
bears(Melursusursinus).The managedforestsof the division aremostly patchy,fragmented,degraded,
andinterspersedwithcropfieldsandvillages withhigh humanandcattlepopulation.The feedingecology
of slothbearswas studiedby analyzing568 scats;21 species of plants,termites,ants,andbees, as well as
unidentifiedanimalmatter(bone, hairsand tissue) were found in bearscats. Year-roundfrequenciesof
occurrenceof animal and plant matterwere similar. Animal matterconstituted87% of scats during
monsoon and 82% duringwinterseasons, but droppedto 65% duringsummer.On percentdry-weight
basis, plant matterwas greaterthan animalmatterin sats in all seasons. Frequencyof occurrenceof
insects was high duringmonsoon (87%) and winter(82%),whereasFicus species were more common
(68%) duringsummerseason. Ficus species were high in percentweight in all seasons. Ficus species
appearto be importantto bears,especiallywhenfieldslackcrops,few otherspecies arefruiting,andsoil is
hard,makingit difficultto dig for antsandtermites.The presenceof groundnutandcorn (maize)in diets
duringthe monsoon suggestscropdamageby bears,therebyincreasingchancesof human-bearconflict.
Key words: animalmatter,crop damage,degradedhabitat,feeding, Ficus, food items, Melursusursinus,plantmatter,
scat analysis, sloth bear
Ursus15(2):212-217(2004)
The sloth bear is endemic to IndianSubcontinent.In
India, sloth bears are found from the foothills of Himalayas to the southernend of Western Ghats. Although
widely distributed,manypopulationsaredecliningdue to
habitatloss and deterioration(Johnsingh 1986), diminished food resources(Murthyand Sanakar1995), timber
and firewood harvesting,and use of their body parts in
medicines (Cowan 1972, Servheen 1990). Sloth bear is
includedin Schedule I of IndianWildlife ProtectionAct
1972 and Appendix I of CITES (Committee on InternationalTradein EndangeredSpecies of Wild Fauna
and Flora).
Most bearsareopportunisticomnivores.As such, their
activities are governedby the availabilityof food items
and dietary components within their habitat. Nutrition
plays an importantrole in the reproductiverateof female
bears (Jonkel and Cowan 1971). Most species of bears
have been documented,at least on occasion, to feed on
insects, especially ants (Joshi et al. 1997). However, the
sloth bear is the only ursid having myrmecophagous
adaptationsto feed on insects, especially termites and
ants (Laurieand Seidensticker1977, Joshi et al. 1997).
Like otherbearsbutunlikeothermyrmecophagousmammals, sloth bear diets vary seasonally and geographically across theirrangefrom Nepal south throughIndia
and Sri Lanka,dependingon the availabilityof food and
hardness of termite mounds (Laurie and Seidensticker
1977, Baskaran1990, Gopal 1991, Gokula et al. 1995,
Baskaranet al. 1997, Joshi et al. 1997).
The objective of this study was to document food
habitsof sloth bearsin a highly disturbedandfragmented
habitat.Informationon compositionand seasonal variation in bear diet can be collected either throughforaging observationsorindirectlythroughscatanalysis(Desai
et al. 1997). Because sloth bears in this area forage primarilyat night, we found it difficultto collect databased
on direct observations,and thus depended on scats to
provideinformationon food habits.
Study area
The study area included the Pendra and Marwahi
administrativeranges (regions) of NBFD in the state of
Chhattisgarh,central India, between 81?45'-82?13'E
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[email protected]
212
FEEDINGECOLOGYAND SLOTHBEARS * Bargali et al.
213
Table 1. Frequency of occurrence of food items in scats of sloth bears by season during 1998-2000 in North
Bilaspur Forest Division, India.
Amountin scat (%)
Food items
Summer (n = 192)
Monsoon (n = 184)
2.6
20.8
0.0
10.9
0.5
64.1
0.5
0.5
2.1
0.0
33.3
21.4
16.1
4.7
15.1
0.5
0.0
12.5
0.0
6.3
2.6
0.0
7.3
2.1
1.6
1.0
0.0
0.0
0.5
3.6
0.0
0.0.
35.3
60.9
0.5
11.4
11.4
79.9
0.0
0.0
0.5
0.5
13.0
6.5
3.3
0.0
0.5
0.0
0.0
0.5
0.0
0.0
0.0
0.5
6.0
2.7
0.5
0.0
32.1
6.0
0.0
0.5
1.1
1.1
Blackant egg shells
Blackant
Red ant egg shells
Red ant
Termiteegg shells
Termites
Bones
Hair
Bees
Animaltissue
Ficus benghalensis
Ficus virens
Ficusreligiosa
Ficusracemosa
Ziziphusmauritiana
Ziziphusoenoplia
Ziziphusnummularia
Aegle marmelos
Briedeliasquamosa
Diospyrosmelanoxylon
Buchananialanzan
Schleicheraoleosa
Syzygiumcumini
Cassia fistula
Madhucaindica(fruit)
Madhucaindica(flower)
Groundnut
Corn
Psidiumguajava
Mangiferaindica
Unknownfruit1
Unknownfruit2
longitude and 22?40'-23?7'N latitude. Forests covered
about337 km2ofthe total study areaof about 1,396 km2
(125 km2 in Pendra and 212 km2 in Marwahi). This
region includes the Chhattisgarhplains and hilly regions
of Maikal range. According to Champion and Seth
(1968), the vegetationof the study areais northerntropical dry deciduouspeninsularsal forest,northerntropical
dry mixed deciduousforest, and northerntropicalmoist
mixed deciduous forest. Most of the forest fragments
consist of small hillocks with bouldersthatoffer suitable
denningareasfor sloth bears.
Habitat available for sloth bears within NBFD is
highly degraded and interspersed with villages and
agriculturalfields. Survivalof sloth bearsdependson the
availabilityof suitablehabitatalong bouldersand rocky
outcropsin forest areas. Because of a lack of irrigation
facilities during summerseason, local inhabitantsgrow
crops only duringthe monsoon season (Jul-Oct). Local
Ursus 15(2):212-217 (2004)
Winter (n = 192)
7.3
60.447.2
1.0
27.1
5.7
74.5
0.5
0.0
0.0
0.0
14.1
29.2
21.9
2.6
14.6
4.7
2.1
6.3
1.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
8.9
2.1
5.7
0.0
0.0
0.0
Annual (n = 568)
14.8
0.5
16.5
5.8
72.7
0.4
0.2
0.9
0.2
20.2
19.2
13.9
2.5
10.2
1.8
0.7
6.5
0.4
2.1
0.9
0.2
4.4
1.6
0.7
0.4
13.4
2.6
2.1
1.4
0.4
0.4
people also collect non-timberforest productsand fuel
wood and graze cattle in forest fragments.
Importantflora of the study area include sal (Shorea
robusta), char (Buchanania lanzan), tendu (Diospyros
melanoxylon),dhawa (Anogeissus latifolia), bel (Aegle
marmelos), palas (Butea monosperma), and bargad
(Ficus benghalensis). Mammalsinclude common leopard (Panthera pardus), golden jackal (Canis aureus),
striped hyena (Hyaena hyaena), Indian fox (Vulpes
bengalensis), toddy cat (Paradoxurushermaphroditus),
wild boar (Sus scrofa), and Indian porcupine (Hystrix
indica).
During April-June, mean temperatureexceeds 40?C.
The months of December and Januaryare the coldest;
mean annualrainfallis 1,381 mm. For study purposes,
we defined 3 seasons: summer (Mar-Jun), monsoon
(Jul-Oct), and winter (Nov-Feb). The study area has
a humanpopulationof about 180,000 and about 150,000
214
ANDSLOTHBEARS* Bargali et al.
FEEDING
ECOLOGY
Analysis
From the total collected, we ran?
80-t
domly selected 16 scats from each
a
70month of collection for analysis (ex60cept during monsoons, when all scats
were used). Scats were weighed sepso3020arately,and only 10%of each scat was
10used in furtheranalysis. Samples were
Annual
soaked in water for 10-15 hrs, then
Winter
Summer
Monsoon
washed in running water to remove
Other animals
EOther plants
*Ficus
Olnsects
O Crops
mud and othermatterusing 0.7 and 0.4
mm sieves. Remaining portions of
Fig. 1. Frequency occurrence of food items in scats of ,sloth bears by each scat were oven dried at 60?C for
season during 1998-2000 in North Bilaspur Forest Division. Errorbars 15-24 hrs. Scat sampleswere analyzed
display 95% bootstrap confidence intervals.
manually by separating components
(such as ants, termites,and fruit)in the
A
scats.
cattle. All the villages in the study area are connected
dissectingmicroscopewas used to identifyfood
items
when
needed. If the scats containedonly ants and
through a network of roads that are drivable during
of the remainingoven-driedscat material
20%
termites,
winterand summer,but not duringthe monsoon season.
was examined. All inseparable,unidentifiablecrushed
matter, including parts of insects and fruits, was
consideredwaste and discarded.
Methods
Scat compositionwas quantifiedby both frequencyof
Collection of scats
occurrence
and percentdry weight of each food item. In
Scat collection, May 1998-December 2000, was
addition
to
quantifyingeach item by species, we grouped
incidentalto otherstudies on sloth bearecology (Gokula
into "insects"' and "otheranimalmatter",
animal
matter
et al. 1995, Baskaranet al. 1997, Joshi et al. 1997). Scats
matter
into 3 categories: "crops" (corn and
and
plant
were collected whenever encountered during transect
"Ficus"
spp. and "otherfruits."
groundnut),
work, tracking of radiocollaredbears, and surveys of
bear dens. Scats were also collected opportunistically
from trapping,feeding, and resting sites as well as along
Results
trails. Scat collection was difficult during the monsoon
Year-rounddiets
season because of increased vegetation cover and
We analyzed a total of 568 scats, consisting of 192
frequentrains;most scats collected duringthe monsoon
from
summermonths, 184 from the monsoon, and 192
were from den sites. Scats were storedin polythenebags
from
winter months. We identified 21 plant species as
and dried in the sun.
well as termites,ants, bees, and unknown
animalmatter(bone, hairs, and tissues) in
bear scats (Table 1). Other than flowers
80
70from Madhuca indica and nuts from
60 .o
groundnut,all plant materialconsisted of
m
:
50fruits.
40 Among the 32 food items identified,
20
termites (72.7%) occurred in scats most
10 often (Table 1). Of the plant species
found in scats, Ficus benghalensis
Winter
Summer
Monsoon
Annual
(20.2%) was found most frequently. On
0 nsects
Other anirrials
Ficus spp
B Other plants
[1Crops
a dry weight basis, plant matterconstituted 89%;the rest (11%)was animalmatter
Fig. 2. Percent dry weight of major food items in sc<ats of sloth (Table 2). F. benghalensis also ranked
bears by seasons during 1998-2000 in NBFD. Error bars display highest in percent composition (20.5%)
on a dry-weight basis, followed closely
95% confidence levels.
100
90 -
i-hi
Ursus 15(2):212-217 (2004)
FEEDINGECOLOGYAND SLOTHBEARS * Bargali et al.
215
Table 2. Percent dry weight composition of food items in the scats of sloth bears by season during 1998-2000
in North Bilaspur Forest Division. Total weight of the mud in scats was 15,488.6 g (average = 27.3 g), total
weight of all scats was 33,581.7 g (average = 59.1 g)
Food items
Blackant egg shells
Blackant
Red ant egg shells
Red ant
Termiteegg shells
Termites
Bones
Hair
Bees
Ficus benghalensis
Ficus virens
Ficus religiosa
Ficus racemosa
Ziziphusmauritiana
Ziziphusoenoplia
Ziziphusnummularia
Aegle marmelos
Briedeliasquamosa
Diospyrosmelanoxylon
Buchananialanzan
Schleicheraoleosa
Syzygiumcumini
Cassia fistula
Madhucaindica(fruit)
Madhucaindica(flower)
Groundnut
Corn
Psidiumguajava
Mangiferaindica
Unknownfruit1
Unknownfruit2
Summer (n = 192)
0.1
0.3
0.0
0.1
0.0
3.3
0.0
1.6
0.1
27.6
15.5
14.6
2.8
10.4
1.9
0.0
5.6
0.0
9.7
0.4
0.0
3.3
0.3
0.1
0.9
0.0
0.0
0.3
1.1
0.0
0.0
Dry weight in scat (%)
Winter(n = 192)
Monsoon (n = 184)
10.9
2.1
1.0
8.3
0.1
0.3
1.2
0.4
0.9
0.8
11.0
4.1
0.1
0.0
0.0
0.0
0.0
0.0
18.8
13.0
28.4
12.8
21.9
3.2
0.0
1.3
14.7
1.9
0.7
0.0
1.4
0.0
1.7
0.0
0.1
0.0
0.0
0.0
0.0
0.0
0.3
0.0
0.0
11.3
1.4
0.0
1.4
0.0
0.0
0.0
4.1
15.2
1.4
0.9
2.4
0.0
0.1
0.0
0.2
0.0
0.3
0.0
Annual (n = 568)
2.5
1.8
0.1
0.5
0.5
4.8
0.1
0.7
0.0
20.5
20.2
15.8
1.8
10.8
1.2
0.6
3.2
0.0
4.4
0.2
0.0
3.2
0.4
0.3
0.4
3.9
0.6
1.1
0.5
0.0
0.0
by F. virens (20.2%). Termiteswere the highest ranking
animal item on a dry-weightbasis.
Frequency of occurrence of insects was highest
(occurring in 77.8% of all scats) followed by Ficus
species (50.5%), other fruits (28.7%), crops (14.8%),
and otheranimalmatter(1.4%;Fig. 1). Expressedby dry
weight, Ficus was highest (58.2%), followed by other
fruits (26.4%), insects (10.2%), crops (4.5%), and other
animal matter(0.8%; Fig. 2).
items during monsoon; termites and ants dominated
diets duringthis season.
In winter, animal matteroccurredin 81.8% of scats.
F. virens was the major food item assessed by dryweight, and the most frequently encountered plant
species. However, termites and ants were by far the
most frequentlyencounteredfood item.
Seasonal diets
During summer,plant matter(90.6%) was identified
in more scats than animal matter (65.1%). F. benghalensis had the highest dietary contributionexpressed
both as frequencyof occurrence(33.3%) and dry weight
(27.6%).
During monsoon, animal matter was found in scats
more frequently(87%)than in summer.Only groundnut
and F. benghalensis appeared to be importantplant
Scat analysishas been used on a wide varietyof bear
speciesto inferdietarycomposition(Schaller1967,Laurie
and Seidensticker1977, Landerset al. 1979, Maehrand
Brady 1984, Hamerand Herrero1987). In some studies,
both scats and stomachcontentshave been used. Dietary
compositionof the sloth bear has been studiedbased on
frequencyoccurrenceandpercentweightof differentfood
items in scats (Gokulaet al. 1995, Baskaranet al. 1997,
Desai et al. 1997) as well as throughdirectobservationsof
Ursus 15(2):212-217 (2004)
Discussion
216
FEEDING
ANDSLOTHBEARS* Bargali et al.
ECOLOGY
feedingbehavior(Joshiet al. 1997).All thesemethodshave
shortcomings.Percentoccurrenceof a particularfood in
scats may differ from actual consumption(Desai et al.
1997,Joshiet al. 1997).Differentplantspeciesalso varyin
theseedsize andpulp-seedsize ratio,whichaffectspercent
weight.
Sloth bearshave morphologicaladaptationsto feed on
insects but, like otherbearspecies, they areopportunistic
omnivores and their diets may vary seasonally and
geographically(Joshiet al. 1997). As in otherstudies,we
found that sloth bears consumed both animal and plant
matter,with variationprobablyrelatedto food availability in differentseasons (Laurieand Seidensticker1977,
Baskaran1990, Gokulaet al. 1995, Baskaranet al. 1997,
Joshi et al. 1997).
In NBFD, we found that insects were the most
frequently encounteredfood item in scats during the
winter and monsoon seasons, whereas Ficus species
were most frequent during the summer season. By
weight, Ficus species dominatedin all seasons. Plants
(mainly Ficus spp.) dominatedin scats during summer.
Expressedas percentdry-weight,plantmatterdominated
in all seasons. Similarly,a studyon sloth bearsin central
India, (Gopal 1991) found that fruits were eaten year
round and were the mainstayof the diet from February
to June, whereas termites, ants, and honey were the
predominantfoods in other months.
We believe that the relative importance of plant
matterin bear scats during summer is due to seasonal
flowering and fruiting. In contrast, hard soil during
summer probably deterred bears from digging for
termites and ants (Davidar 1983, Gopal 1991, Joshi
et al. 1997). Ficus species occur throughoutthe year in
different stages of fruiting. We interpret the high
frequency groundnuts in scats during monsoon as
evidence of crop raiding. We also noted extensive
digging for termitesand ants in crop fields close to the
den sites duringmonsoon. With the onset of monsoon,
rain water softens the soil, and bears have been
documented digging extensively for termites and ants
at this time (Schaller 1967, Davidar 1983, Gopal 1991,
Joshi et al. 1997). With the onset of winter, Ficus spp.
and otherplantmatterbecame important,but crops were
also present in low frequencybecause bears consumed
crops left in fields after the harvestingwas over.
Residents of NBFD collect a number of non-timber
forestproducts(NTFP)that are also used by sloth bears.
NTFP materialscollected include flowers and fruits of
mahuwa (Madhuca indica) and fruits of bel (Aegle
marmelos),char (Buchananialanzan),jamun (Syzygium
cumini), and tendu (Diospyros melanoxylon). Such
collection may limit their availability for bears. Ficus
spp. arenot used by local people, so arereadilyavailable
for the bears.
In the degradedhabitatsof NBFD, both animal and
plant matter contribute to the diets of sloth bear.
However, Ficus spp. play importantroles by providing
a constant supply of food throughoutthe year. This is
particularlyimportantduringsummerwhen there are no
crops in fields to raid and fewer fruiting species, and
bears find it difficult to dig for termiteand ants.
We recommendthatcuttingand loppingof Ficus trees
aroundslothbearden sites shouldbe prohibited.To lessen
conflicts, villagers should avoid growing corn and
groundnutcropsnearden sites and shouldbe encouraged
to grow crops of less interestto bears.
Acknowledgments
We are grateful to V.B. Sawarkar, Director of
Wildlife Institute of India for his help and support in
conductingthe study. Thanks are also due to the Chief
Wildlife Warden, Conservator of Forests, Divisional
Forest Officer and field staff of North Bilaspur Forest
Division for theirhelp and cooperationin conductingthe
field work. We thank V. Sharmaand Mr. Mukesh for
providing technical support.This study was funded by
the Wildlife Instituteof India.
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217
Received: 9 August 2002
Accepted: 14 January 2004
Associate Editor: R.B. Harris