ORIGINAL ARTICLE

Drastic population decline and conservation prospects of roadsidedark-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

� Japan 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. 1 Mysore, 2 Antharsanthe, 3 Begur, 4 Handpost, 5 Hangala,

6 Nanjangud, 7 Chamarajanagar, 8 Yelandur, 9 Kollegal, 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

Nt = N0ert in which Nt was the present number of animals,

N0 was the number during the previous survey, e was the

base of natural logarithms, and t was 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 1 presents 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

1989a 1998b 2003c 2009d 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 (v2 = 7.88, df = 3,

p \ 0.05). Likewise, the number of animals has declined

from 1,207 in 1989 to 697 in 2009 (v2 = 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) (v2 = 96.61, df = 3,

p \ 0.01 and v2 = 189.49, df = 3, p \ 0.01, respectively),

the number has increased in SF (from 210 to 246)

(v2 = 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 (v2 = 15.25, df = 3, p \ 0.01)

as well as in the total population from 32 groups in 1989 to

12 groups in 2009 (v2 = 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 4 show that the age–

sex ratios did not differ among the habitat types for adult

male:adult female (Kruskal–Wallis v2 = 1.19, df = 2,

p = 0.55), adult:immature (Kruskal–Wallis v2 = 1.65,

df = 2, p = 0.44) and adult female:immature (Kruskal–

Wallis v2 = 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

r Overall r No. 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)a1989 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)a1989 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)a1989 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 surveyedb 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

v2 = 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 v2 = 3.04, df = 2, p = 0.22). However, a

significant difference among surveys was observed for

adult:immature ratio (Fig. 4) (Kruskal–Wallis v2 = 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 2009 1989 1998 2003 2009 1989 1998 2003 2009

Intensive cultivation Wet cultivation Scrub forest

surveys

Ad

ult

mal

e :

Ad

ult

fem

ale

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

Ad

ult

fem

ale

: Im

mat

ure

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

Ad

ult

: Im

mat

ure

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.

References

Bhagwat SA, Kushalappa CG, Williams PH, Brown ND (2005) A

landscape approach to biodiversity conservation of sacred groves

in the Western Ghats of India. Conserv Biol 19:1853–1862

D’Souza L, Singh M (1992) Density and demography in roadside

bonnet monkeys (Macaca radiata) around Mysore. J Ecobiol

4:87–93

Eudey AA (2008) The crab-eating macaque (Macaca fascicularis) are

widespread and rapidly declining. Primate Conserv 23:129–132

Hill CM (2000) Conflict of interest between people and baboons: crop

raiding in Uganda. Int J Primatol 21:299–315

IUCN (2010) IUCN: red lists of threatened species. 2010.4.

http://www.iucnredlist.org. Accessed 22 Nov 2010

Kumara HN, Kumar S, Singh M (2009) Of how much concern are the

‘least concern’ species? Distribution and conservation status of

bonnet macaques, rhesus macaques and hanuman langurs in

Karnataka, India. Primates 51:37–42

Mgumia FH, Oba G (2003) Potential role of sacred groves in

biodiversity conservation in Tanzania. Environ Conserv

30:259–265

Molur S, Brandon-Jones D, Dittus W, Eudey A, Kumar A, Singh M,

Feeroz MM, Chalise M, Priya P, Walker S (2003) Status of

South Asian primates: conservation assessment and management

plan (C.A.M.P.) workshop report, 2003. Zoo Outreach Organi-

zation/CBSG-South Asia, Coimbatore

Muroyama Y, Eudey AA (2004) Do macaque species have a future?

In: Thierry B, Singh M, Kaumanns W (eds) Macaque societies: a

model for the study of social organization. Cambridge University

Press, Cambridge, pp 328–332

Roonwal ML, Mohnot SM (1977) Primates of South Asia: ecology,

sociobiology and behavior. Harvard University Press,

Cambridge

Saj TL, Sicotte P, Paterson JD (2001) The conflict between vervet

monkeys and farmers at the forest edge in Entebbe, Uganda. Afr

J Ecol 39:195–199

Sharma KD (1998) The study of habitat related demographic patterns

in bonnet macaque (Macaca radiata). Master’s dissertation,

University of Mysore, Mysore

Singh M, Rao R (2004) Population dynamics and conservation of

commensal bonnet macaques. Int J Primatol 25:847–859

Southwick CH, Siddiqi MF (1994a) Primate commensalism: the

rhesus monkey in India. Rev Ecol 49:223–231

Southwick CH, Siddiqi MF (1994b) Population status of nonhuman

primates in Asia, with emphasis on rhesus macaque in India. Am

J Primatol 34:51–59

Watanabe K, Muroyama Y (2004) Recent expansion of distribution

and management problems of Japanese macaques. In: Paterson

JD, Wallis J (eds) Commensalism and conflict: the primate–

human interface. American Society of Primatologists, Norman,

pp 400–419

154 Primates (2011) 52:149–154

123