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ORIGINAL ARTICLE
Drastic population decline and conservation prospects of roadside
dark-bellied bonnet macaques (Macaca radiata radiata)
of southern India
Mewa Singh •Joseph J. Erinjery •
Theethira S. Kavana •Kuladeep Roy •
Mridula Singh
Received: 26 July 2010 / Accepted: 16 January 2011 / Published online: 15 February 2011
ÓJapan Monkey Centre and Springer 2011
Abstract We carried out a survey on roadside dark-bel-
lied bonnet macaques (Macaca radiata radiata) on the
highways around the south Indian city of Mysore. The
present survey was the fourth since 1989 on the same
populations. We divided the habitats into intensive culti-
vation (IC), wet cultivation (WC), and scrub forests (SC).
The number of groups has significantly reduced from 54 to
31 and the number of animals has declined from 1,207 to
697 from 1989 to 2009. This decline has been recorded
only in the IC and WC areas, whereas the population in SC
with places of Hindu worship has remained stable. Due to
the loss of roadside Ficus trees over the years, the habitat of
the monkeys has almost disappeared. Since bonnet maca-
que is not primarily a forest-dwelling species, the seem-
ingly widespread primate may soon become ‘threatened’
if the non-forest populations continue to decline. Scrub
forests in small hillocks housing Hindu temples remain
the only prospective places for conservation of bonnet
macaques.
Keywords Bonnet macaque Scrub forests
Conservation Hindu temples Population decline
Introduction
Most of the primate populations have been declining dur-
ing the past few decades due to habitat loss, habitat frag-
mentation, and biotic pressures. As a result, a large number
of primate species are listed today as ‘threatened’ (IUCN
2010). Due to its diversity of habitat types, India, in
addition to a large number of other faunal species, is home
to 22 species of primates of which six are listed as
‘threatened’ and another six as ‘vulnerable’ (IUCN 2010).
Rhesus macaques, bonnet macaques, and Hanuman langurs
of the Indian subcontinent are considered ‘least concern’
due to their widespread distribution and large numbers.
Whereas the conservation biologists and wildlife managers
have paid serious attention to the conservation of ‘threa-
tened species’, little concern has been shown to the so-
called ‘least concern’ species. However, the numbers and
the distributional ranges of several such primate species in
India have drastically declined over the past few decades
(Kumara et al. 2009; Singh and Rao 2004; Southwick and
Siddiqi 1994a,b). It has been suggested that conservation
measures should be taken up for such species now before
these species also become ‘threatened’ (Kumara et al.
2009).
Periodic monitoring is the first step in assessing the
status of wild populations in order to devise the appropriate
conservation measures (Eudey 2008). Whereas several
surveys have been carried out on primate populations in
India, not a single large population has been monitored
over the long term. The bonnet macaque is an endemic
species to southern India ranging from the Godavari River
in the north to the peninsular tip of the south (Roonwal and
Mohnot 1977). The northern part of its range is inhabited
by the dark-bellied bonnet macaque (Macaca radiata
radiata) and the southern part of the range is inhabited by
M. Singh (&)J. J. Erinjery T. S. Kavana K. Roy
Biopsychology Laboratory, University of Mysore,
Mysore 570006, India
e-mail: mewasingh@bsnl.in
M. Singh
Maharaja’s College, University of Mysore,
Mysore 570006, India
123
Primates (2011) 52:149–154
DOI 10.1007/s10329-011-0234-x
the pale-bodied bonnet macaque (M. r. diluta) (Molur et al.
2003). Large populations of these two subspecies inhabit
human-inhabited landscapes and only a small portion of the
population inhabits forests and protected areas for wildlife
(Kumara et al. 2009). Over the past few decades, there has
been a rapid development in India in the areas of agricul-
tural expansion, concrete constructions, and widening of
highways. On one hand, these developmental activities
have drastically reduced the habitat of the bonnet maca-
ques, and on the other, people have increasingly become
intolerant of the macaques due to their crop-raiding
behavior. These changes are expected to influence the local
range and population size of the species.
For the past 20 years, we have been monitoring a pop-
ulation of dark-bellied bonnet macaques around the city of
Mysore within a radius of about 100 km. The previous
surveys were carried out in 1989 (D’Souza and Singh
1992), 1998 (Sharma 1998), 2003 (Singh and Rao 2004),
and the present survey was carried out in November to
December of 2009. In this article, we report the present
status of the bonnet macaque population in this region and
analyze the overall trends in this metapopulation and the
subpopulations. We also suggest possible conservation
measures for the non-forested bonnet macaques.
Study area
The study included eight highways around the south Indian
city of Mysore (12.18°N and 76.42°E), 11 adjacent roads
connecting the highways, and one scrub forest (SF) at
Chamundi Hill near the city (Fig. 1). We surveyed a total
of 1,052 km. The study area was divided into three habitat
types.
Intensive cultivation
This is the region where the agricultural lands on roadsides
are irrigated through canals and wells and there is year-
round cultivation of sugarcane, vegetables, rice paddies,
cereals, etc. The dominant roadside vegetation included
sparse trees of Ficus bengalensis,F.religiosa,Tamarindus
indica, and Eucalyptus sp. The monkeys often raided crops
for food.
Wet cultivation
The agriculture in this habitat type was dependent on rains
during the monsoon months between June and October.
The cultivated crops included groundnut, cereals, and
beans. The roadside vegetation was sparse and included
Ficus bengalensis,F.religiosa,Tamarindus indica,Cocos
nucifera,Polyalthia longifolia, and Eucalyptus sp. In this
habitat as well, the monkeys often raided the crops for
food.
Scrub forest
The Chamundi Hill range situated near the city of Mysore
consisted of thorny and SFs dominated by Acacia,Aza-
dirachta,Eucalyptus, and Zizyphus sp. This is a reserved
forest and there are no agricultural lands within the hill
range. A characteristic feature of the hill is the presence of
two places of Hindu worship, one at the bottom of the hill
and one at the top of the hill. These temples are regularly
visited by devotees, tourists, and monkeys, which, in
addition to the feeding in the forest, receive abundant
handouts of cooked food from visitors.
Methods
We carried out the study over a period of 2 months
between November and December of 2009. We traveled
the distance by foot and on a motorcycle/jeep at the speed
of \6 km/h. Since all the monkey groups were visible on
the roadsides, and the general location of each monkey
group has been known for the past two decades, we used
the method of ‘total counts’. The location map for these
groups was prepared in 1989 (D’Souza and Singh 1992)
Fig. 1 Map of the study area. Double lines show the roads that were
surveyed. 1Mysore, 2Antharsanthe, 3Begur, 4Handpost, 5Hangala,
6Nanjangud, 7Chamarajanagar, 8Yelandur, 9Kollegal,10 T. Narsipura,
11 Ramanagaram, 12 Kanakapura, 13 Periyapatna, 14 Anechaukur,
15 Chamundi Hills, 16 Gaddige, 17 Hunsur, 18 HD Kote, 19 Gundelpet,
20 HN Pura, 21 Channarayapatna, 22 Srirangapatna
150 Primates (2011) 52:149–154
123
and even during the present survey, we located a group
within 0.5 km of the 1989 location. If a group near an
earlier location was not sighted, a thorough search of the
surrounding area including the crop lands was made. Fur-
ther, the disappearance of the group was confirmed with the
villagers and the farmers in the area. After spotting a group,
we collected data on the number of animals in each age–
sex class. Due to the flat terrain, sparse trees, and clear
visibility in all habitat types, it was easy to see all the
animals. All the animals in a group of bonnet macaques
were mostly within a distance of about 50 m. Still, we
spent a few hours with each group and made repeated
counts to ensure that all animals were counted. The age–
sex classes included adult males (C5 years), adult females
(C3 years), sub-adult males (3–5 years), juvenile
(1–3 years), and infants (B1 year). Since the survey was
linear transects, we calculated the encounter rate as number
of groups/animals per kilometer. If the distance between
any two groups was more than 4 km, we considered these
groups as belonging to different subpopulations. We cal-
culated the occupied area as the total distance covered by a
subpopulation plus 4 km (adding 2 km on each side). We
calculated the intrinsic rate of natural increase (r)as
N
t
=N
0
e
rt
in which N
t
was the present number of animals,
N
0
was the number during the previous survey, e was the
base of natural logarithms, and twas the number of years
between two surveys. We compared the present data with
those from the previous surveys. All the previous surveys
were carried out employing the same methodology as in the
present survey as one of the authors (Mewa Singh) initiated
these surveys in 1989 and has since then been supervising
these studies with an active participation.
Results
Overall population dynamics
Table 1presents the data on different sectors of survey,
habitat type, distance covered in each sector, and the
number of bonnet macaque groups and animals during the
four surveys. The number of groups has significantly
Table 1 Bonnet macaque populations in different transects in four different surveys
Sector Sector no.Habitat
type
Distance
covered (km)
Number of groups Number of animals
1989
a
1998
b
2003
c
2009
d
1989 1998 2003 2009
Mysore–Antharsanthe 1 WC 70 7 7 4 2 113 116 43 26
Handpost–Begur 2 WC 44 3 3 4 2 62 48 71 27
Mysore–Hangala 3 WC 75 11 10 10 5 192 157 170 132
Nanjangud–Chamarajanagar 4 WC 39 2 3 1 0 40 50 21 0
Chamarajanagar–Yelandur 5 WC 43 1 2 2 0 28 60 11 0
Kollegal–T. Narsipura 6 WC 67 9 8 6 7 257 169 125 102
Mysore–Ramanagaram 7 IC 91 7 8 8 1 133 103 168 34
Ramanagaram–Kanakapura 8 WC 28 0 1 1 2 0 12 16 19
Mysore–Kanakapura 9 WC 98 6 5 3 4 166 95 46 111
Mysore–Periyapatna 10 IC 42 1 1 0 0 6 6 0 0
Periyapatna–Nagarahole Road 11 IC 35 0 0 1 0 0 0 13 0
Chamundi Hills Road 12 SF 19 7 7 7 8 210 206 266 246
Kollegal Cross Road 13 WC 10 0 0 0 0 0 0 0 0
Mysore–Gaddige-Hunsur 14 IC 85 0 0 0 0 0 0 0 0
Gundelpet–Chamarajanagar 15 WC 34 0 0 0 0 0 0 0 0
Mysore–HN Pura 16 IC 92 0 0 0 0 0 0 0 0
HN Pura–Channarayapatna 17 IC 22 0 0 0 0 0 0 0 0
Mysore–Channarayapatna 18 IC 88 0 0 0 0 0 0 0 0
Srirangapatna–T. Narsipura 19 IC 35 0 0 0 0 0 0 0 0
T. Narsipura–Nanjangud 20 WC 35 0 0 0 0 0 0 0 0
Total 1,052 54 55 47 31 1,207 1,022 950 697
a
D’Souza and Singh (1992)
b
Sharma (1998)
c
Singh and Rao (2004)
d
Present study
Primates (2011) 52:149–154 151
123
reduced from 54 in 1989 to 31 in 2009 (v
2
=7.88, df =3,
p\0.05). Likewise, the number of animals has declined
from 1,207 in 1989 to 697 in 2009 (v
2
=138.08, df =3,
p\0.01).
Population dynamics habitat-wise
The data on population status and dynamics during the four
surveys for each of the habitats are presented in Table 2.
Whereas the number of animals has significantly declined
in intensive cultivation (IC) (from 139 to 34) and wet
cultivation (WC) (from 858 to 417) (v
2
=96.61, df =3,
p\0.01 and v
2
=189.49, df =3, p\0.01, respectively),
the number has increased in SF (from 210 to 246)
(v
2
=10.83, df =3, p\0.01). The present population in
WC is about 48.61% of the 1989 population (r=-0.07/
year). In IC, the present population is only 24.46% of the
1989 population (r=-0.04/year). The SF population has
recorded a growth with an r=0.01/year. Although in
2009, the mean group size in SF and WC was 30.75 and
18.95, respectively, the size did not differ significantly due
to large variations in group size in both habitats (t=1.93,
df =28, p=0.06). The most noticeable feature of groups
size is the significant decline in the number of groups in the
medium size range (11–30 animals) from 26 in 1989 to
only seven in 2009 in WC (v
2
=15.25, df =3, p\0.01)
as well as in the total population from 32 groups in 1989 to
12 groups in 2009 (v
2
=15.08, df =3, p\0.01). SF with
12.94 animal/km had the highest encounter rate followed
by WC with 0.76 animals/km and IC with 0.07 animals/
km. The area actually occupied by the macaques in the
survey region reduced from 25 to 4 km in IC, from 117 to
77.5 km in WC whereas it has remained the same in SF. In
IC, six subpopulations have now reduced to only one
subpopulation. In WC, 18 subpopulations in 1989 have
now become 17 subpopulations with only 48.61% of the
original population. The increased distance among the
subpopulations therefore indicates a high degree of popu-
lation fragmentation. All groups in SF have overlapping
home ranges making it a single subpopulation. Overall, the
number of animals per subpopulation has reduced from
48.3 in 1989 to 36.68 in 2009.
Age–sex ratios in habitat types
The data presented in Figs. 2,3, and 4show that the age–
sex ratios did not differ among the habitat types for adult
male:adult female (Kruskal–Wallis v
2
=1.19, df =2,
p=0.55), adult:immature (Kruskal–Wallis v
2
=1.65,
df =2, p=0.44) and adult female:immature (Kruskal–
Wallis v
2
=3.04, df =2, p=0.22). Although the pro-
portion of adult females recorded an increase during 1998
Table 2 Bonnet macaque populations in different habitat types during four surveys
Habitat type Year No. of
groups
No. of
animals
Mean
group
size
Groups/
km
Animals/
km
Occupied
area (km)
Animals in
occupied
area/km
rOverall rNo. of sub-
populations
Animals/sub-
population
Intensive
cultivation
(490 km)
a
1989 8 139 17.37 0.016 0.28 25 (5.10)
b
5.56 – 6 23.2
1998 10 121 12.10 0.020 0.25 31 (6.33) 3.90 -0.015 6 20.2
2003 9 181 20.11 0.018 0.37 29 (5.92) 6.24 0.080 6 30.2
2009 1 34 34.00 0.002 0.07 4 (0.81) 8.50 -0.280 -0.07 1 34.0
Wet cultivation
(543 km)
a
1989 39 858 22.00 0.072 1.58 117 (21.57) 7.33 – 18 47.7
1998 38 695 18.29 0.070 1.28 124 (22.84) 5.60 -0.023 21 33.1
2003 31 503 16.23 0.057 0.93 108 (19.89) 4.66 -0.065 24 21.0
2009 22 417 18.95 0.040 0.77 77.5 (14.27) 5.38 -0.030 -0.04 17 24.5
Scrub forest
(19 km)
a
1989 7 210 30.00 0.368 11.05 19 (100) 11.05 – 1 210.0
1998 7 206 29.43 0.368 10.84 19 (100) 10.84 -0.002 1 206.0
2003 7 266 38.00 0.368 14.00 19 (100) 14.00 0.051 1 266.0
2009 8 246 30.75 0.420 12.95 19 (100) 12.94 -0.010 0.01 1 246.0
Overall
(1,052 km)
a
1989 54 1,207 22.35 0.051 1.15 161 (15.34) 7.50 – 25 48.3
1998 55 1,022 18.58 0.052 0.97 174 (16.54) 5.87 -0.018 28 36.5
2003 47 950 20.21 0.045 0.90 156 (14.83) 6.09 -0.015 31 30.6
2009 31 697 22.49 0.029 0.66 100.5 (9.55) 6.93 -0.050 -0.03 19 36.7
a
km surveyed
b
Values in parentheses indicate percent area occupied
152 Primates (2011) 52:149–154
123
in all habitats and then steadily decreased, the difference
for the adult male:adult female ratio was not significant
among habitats over the surveys (Fig. 2) (Kruskal–Wallis
v
2
=6.18, df =3, p=0.10). The ratio of immature
individuals against adult females has declined over the
surveys with a sharper decline in IC, though the difference
among habitats for this ratio was non-significant (Fig. 3)
(Kruskal–Wallis v
2
=3.04, df =2, p=0.22). However, a
significant difference among surveys was observed for
adult:immature ratio (Fig. 4) (Kruskal–Wallis v
2
=8.13,
df =3, p=0.04) in which the immature ratio was 1:0.94,
1:0.71, 1:0.70, and 1:0.58 during 1989, 1998, 2003, and
2009 surveys, respectively. This indicated that the number
of immature individuals in relation to adults has been
continuously decreasing with a sharper decrease in IC.
Discussion
The main results of the present study reveal that the pop-
ulation of roadside bonnet macaques, a so-called ‘least-
concern species’, has been drastically declining, and the
farmers whose crops are often raided by these monkeys are
not favorably disposed towards coexistence with the
monkeys. Except in the SF habitat, which also houses two
important places of Hindu worship in the Chamundi Hill,
the population of bonnet macaques has continually
declined over a period of 20 years as indicated by the four
surveys. Further, the results also showed that there has
been a continuous decline in the adult:immature ratio in the
groups from 1:0.94 in 1989 to only 1:0.58 in 2009. This
proportion of immature individuals is too small as com-
pared to the ratio of 1:1.14 for bonnet macaques in the
entire state of Karnataka, which includes several forest
habitats (Kumara et al. 2009). The total decline in the
population of bonnet macaques in the study area has been
due to the disappearance of several groups and not due to a
decrease in the group size. The results clearly indicate that
the bonnet macaques in their traditional habitats of road-
sides adjoining crop lands have no conservation future at
all. This is probably true of the other primates such as
rhesus macaques in northern India (Southwick and Siddiqi
1994a,b).
During the past two decades or so, the Indian economy
has opened up as a more liberal free-market economy. This
has accelerated the pace of developmental activities that
includes the widening of highways. All the highways
included in our surveys had almost a continuous canopy of
banyan (Ficus bengalensis) trees some 30 years ago
(Mewa Singh, pers. obs.) and these fig trees provided an
important resource base for the monkeys and other arboreal
animals including squirrels and birds. A typical example in
the present study was that of Sector 7 (Mysore-Ramana-
garam Road), which links Mysore to the metropolitan city
of Bangalore. In the early 1960s, the entire stretch of
140 km between Mysore and Bangalore had an almost
continuous distribution of bonnet macaques (Paul Simonds,
personal information). In the year 2004, the government
started laying a four-lane highway on this road. Almost all
the roadside trees have been felled, which has left little
shelter or resource base for the monkeys. Similar road
widening has also been carried out in the other IC regions
since 2004. The last resort for the remaining monkeys in
these areas has been raiding crops for their food, which has
now become a daily affair. At the same time, the govern-
ment has provided more electricity to the farmers and the
once only monsoon fed crop lands are now irrigated by
electric bore wells. The cultivation, therefore, has become
more intensive and the farmers have increasingly become
intolerant of the crop-raiding monkeys. These farmers now
0.00
0.50
1.00
1.50
2.00
2.50
1989 1998 2003 200 9 1989 1998 2003 2009 1989 1998 2003 2009
Intensive cultivation Wet cultivation Scrub forest
surveys
Adul t ma le : Ad ult fem al e
Adult male Adult female
Fig. 2 Adult male:adult female ratio in different habitats over four
surveys
0.00
0.50
1.00
1.50
2.00
2.50
surveys
Adul t fem ale : I m matu re
Adult female Immature
1989 1998 2003 2009 1989 1998 2003 2009 1989 1998 2003 2009
Intensive cultivation Wet cultivation Scrub forest
Fig. 3 Adult female:immature ratio in different habitats over four
surveys
0.00
0.20
0.40
0.60
0.80
1.00
1.20
surveys
Adult : Immature
Adult Immature
1989 1998 2003 2009 1989 1998 2003 2009 1989 1998 2003 2009
Intensive cultivation Wet cultivation Scrub forest
Fig. 4 Adult:immature ratio in different habitats over four surveys
Primates (2011) 52:149–154 153
123
want the remaining monkeys trapped and released away
from their crops.
However, it may be noted that though the Indian farmer
has a negative attitude towards monkeys in a situation of
human–monkey conflict, he is not opposed to the conser-
vation of monkeys in areas where there is little such con-
flict. This is evident from the fact that the population in the
SFs of Chamundi Hill, which is also surrounded by crop
lands, has remained stable, and has even increased over the
years. We proposed earlier (Singh and Rao 2004) that since
India is dotted with small hillocks, many of which also
house Hindu temples, such places may be the only prospect
for conservation of non-forested primates. Sacred groves in
India and Africa have been observed to have a high degree
of protection and biodiversity (Bhagwat et al. 2005;
Mgumia and Oba 2003), and such places can also support
commensal primates. Since such species of primates have
very low densities in protected forests, a neglect of con-
servation of these non-forested populations may soon result
in these species also becoming threatened or undergoing
local extinction. This is probably true even for non-forest-
dwelling primate species in other countries such as
baboons and mangabeys in Africa (Hill 2000; Saj et al.
2001). In some regions of western Japan, the Japanese
macaques have already undergone local extinction
(Watanabe and Muroyama 2004). Muroyama and Eudey
(2004) advocate that theories and techniques that address
the needs of local people for relief from crop raiding by
macaques need to be developed for effective conservation
of such species.
Acknowledgments This work was carried out under ‘Ramanna
Fellowship’ grants from the Department of Science and Technology,
Government of India to Mewa Singh.
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