Activity Budgets and Feeding Behaviour of TheButon Macaque (Macaca brunnescens).

By Kate Andrews

Macaca brunnescens. Photographs by D. Slater (left) and K. Andrews (right).

This study was carried out in partial fulfilment of the requirements for the degree of

B.Sc. (Hons.) Biology at the University of Aberdeen.

I hereby declare that this thesis is my own work. Where I have used the work of other persons

or quoted the work of other persons the sources of the other work or information have been

detailed explicitly in the presentation.

. 14/01/03

CONTENTS

Abstract ........................................................................................................1

Introduction..................................................................................................3Background and geographical area ........................................................................................ 3Sulawesi Macaques ................................................................................................................ 5Conservation of M. brunnescens ........................................................................................... 7Macaque ecological background. ........................................................................................... 8Aims and objectives ............................................................................................................. 10

Methods and Materials ...............................................................................11Study site.............................................................................................................................. 11Study animals ....................................................................................................................... 12Preliminary observations ...................................................................................................... 14Data Collection..................................................................................................................... 15Data analysis......................................................................................................................... 19

Results.........................................................................................................21Activity budgets.................................................................................................................... 21Macaque diet ........................................................................................................................ 41Other observations ................................................................................................................ 58

Discussion ...................................................................................................64Activity budgets.................................................................................................................... 64Macaque diet ........................................................................................................................ 76

Conclusions.................................................................................................85

Future work ................................................................................................87

Limitations, biases and improvement of the study. .....................................88

Acknowledgements .....................................................................................90

References...................................................................................................91

1Abstract

There have been very few studies of the species Macaca brunnescens (the Buton macaque)

and there are not yet any published works pertaining to it. A study is therefore presented that

builds upon some of the preliminary findings from the years 2000 and 2001 and aims to

consolidate these and make new discoveries.

M. brunnescens is one of seven species endemic to Sulawesi, Indonesia. Habitat

encroachment such as logging and farming has reduced potentially viable areas for this

species to succeed. Further studies are therefore vital to preventing further endangerment.

The focus of the work was daily activity budgets, with particular emphasis on feeding

behaviour since the incorporation of crops into the diet has altered human-monkey

relationships and become a big problem in Indonesian village communities. The study period

lasted 4 weeks, during which time 2,164 behavioural observations were recorded using the

scan-sampling method, and 253 feeding bouts were noted in all-observations sampling.

M. brunnescens spent on average 30.86% of the daily activity budget feeding, 27.41% in

locomotion, 17.13% resting, 13.77% grooming, 2.81% foraging, 2.26% in aggression, 1.3%

in vigilance, 4.05% playing and 0.37% in other activities. Activity budget differences were

observed for the different age/sex classes, and differences were found in diurnal patterns of

behaviour, although neither finding was statistically significant. Time spent in nearby farms

increased over the study period and this seemed to affect the way behaviour budgets were

partitioned. M. brunnescens was found to be semi-terrestrial with a slight arboreal preference.

50 types of food were recorded as M. brunnescens foods and of these approximately 24 have

not previously been identified in the diet of this species. Crop raiding occurred on 62.5% of

2the study days and the increase in incorporation of crops into the diet appeared to affect

partitioning of the activity budget.

M. brunnescens was found to be highly adaptable to changes occurring in its habitat, coping

by being able to exploit a variety of food sources and to alter its home range and sleeping

sites. The study also demonstrated the consequences of using extreme deterrence methods

such as poisoning, highlighting the extent of the crop raiding problem in this location.

3 Figure 1: Southeast Asia

Introduction

Background and geographical area

Indonesia has one of the worlds richest natural environments, harbouring a high diversity of

plant and animal species (Turner et al., 2000). However there is still much to learn about the

country and its environment. The Republic of Indonesia is the worlds most expansive

archipelago, stretching almost 5,000km from Sabang off the northern tip of Sumatra, to

Merauke in south-eastern Irian Jaya (Turner et al., 2000) (Figure 1). Officially the archipelago

contains 13,677 islands of varying sizes, 6,000 of which are inhabited. Sulawesi (formerly

known as Celebes) is one of the 5 main islands of Indonesia (Figure 1), measuring 189,216

sq. km (Turner et al., 2000). The southeastern region of this island is the location for the

present study.

4Nearly two thirds of Indonesia is covered by tropical rainforest, owing to its high rainfall and

year round humidity which result in an even overall climate. Indonesian islands have 2

seasons: a wet season, which falls between October and April, and a dry season beginning

around May and ending in September.

Like most of the country,

Sulawesi is mountainous, its

surface consisting largely of

coral limestone. The island is

home to 127 indigenous

mammals; 61% of which are

endemic to Sulawesi, but many

are in danger of extinction

(Turner et al., 2000). Similarly,

27% of bird species (Turner et

al., 2000) found on the island are

endemic but may also be

endangered. The discovery of the

wildlife inhabiting Sulawesi and

Borneo first gave rise to a theory

that the Indonesian archipelago was inhabited by one distinct fauna in the east and one in the

west (Turner et al., 2000). This theory struck the English naturalist Alfred Russel Wallace

who, alongside Darwin, established the theory of natural selection. Sulawesi and Lombok to

the east were thought (due to their similarities in fauna type) to have once belonged to the

Australian continent; and Borneo and Bali to the west, had once been part of Asia. The

Figure 2: Southeast Sulawesi.

5differences in wildlife on Sulawesi and Borneo were surprising since the islands are so similar

in climate and geography, but in 1859 the 2 regions of fauna became divided by an imaginary

boundary called Wallaces line. Sulawesis wildlife was so unusual that Wallace suspected it

was once part of both Asia and the Australian continent, a fact that has since been proven by

geologists (Turner et al., 2000).

Named after Alfred Russel Wallace, the Operation Wallacea Trust was established in order to

support activities that could directly contribute towards the conservation of biodiversity in the

Wallacea region of eastern Indonesia (Operation Wallacea website, 2001). The trust is funded

by volunteers who take part in expeditions that carry out the aforementioned objective. The

present study is based on data collected as part of an Operation Wallacea expedition.

Scientists and volunteers involve themselves with various biological, environmental and

geographical research projects, the data from which are used to achieve conservation

objectives.

The present study took place on Buton Island, a small island off the south-east coast of

mainland Sulawesi (circled, figure 2). There is a significant lack of knowledge regarding the

biology of Buton Island, its flora and its fauna, and this has prompted the recent increase in

interest here.

Sulawesi Macaques

Indonesia has the widest range of primate species in Asia (MacKinnon, 1986a and b, in Kilner

2001 (1)). The focus of the present study is a macaque species, of which there are nineteen

worldwide. Seven of these species are endemic to the island of Sulawesi, more than any other

comparable land area (Reed et al., 1997). Their taxonomy has been an area of debate for

6sometime, but widely accepted is Foodens (1969) classification of the seven Sulawesi

macaque species, which he placed all together in one genus Macaca (Table 1).

Table 1: Sulawesi Macaque species information (Kilner, 2000)

Species(Fooden1969)

Commonmacaque name(Fooden 1969)

Distributionin Sulawesi

Date ofprotection inIndonesia(MacKinnon1986)

IUCN redlist category(WCMC)

Presence ofcaptivepopulations(ISIS, Wide etal. 1994)

nigra Black crested Northeast 1970 Endangered Yes

nigrescens Dumoga-bone North 1970 Lower risk No

hecki Hecks Northwest N/A Lower risk No

tonkeana Tonkean Central N/A Lower risk Yes

maura Moor Southwest 1977 Endangered Yes

ochreata Booted Southeast 1977 Datadeficient

1 individual

brunnescens ButonIslands ofButon andMuna, SE.

1977 Vulnerable No

Research into the taxonomy (Albrecht, 1978; Thorington and Groves, 1970; in Kilner (1),

2001; Groves, 1980; Fooden, 1969) and genetics (Ciani et al., 1989; Fooden and Lanyon,

1989; in Kilner (1), 2000 of these species has taken place. However, few ecological or

behavioural studies have been published (OBrien and Kinnaird, 1997; Reed et al., 1997;

Rosenbaum et al. 1998; in Kilner (1), 2000). Categorised as vulnerable by the IUCN red list

(Table 1), Macaca brunnescens (the Buton macaque) is the species of interest for the present

study. Very little is known about this species and there are no published studies which focus

upon it.

7Conservation of M. brunnescens

M. brunnescens lives in the lowland and hill forests (MacKinnon, 1986) of Buton and Muna

islands and is found nowhere else in the world. Large-scale habitat destruction on Buton,

through logging (deforestation rate on Buton is approximately 10% per annum (Operation

Wallacea report, 1999)) and farming has reduced potentially viable areas for these medium

sized mammals to succeed (Stanier, 2001). Habitat loss has already been identified as the

single greatest threat to the continued survival of virtually all primate species (Rosenbaum et

al., 1998; in Gore et al., 2001). Therefore information such as population estimates and

details of home range, food resources and habitat use, are vital for the conservation of this

endemic species. Such information could be useful in predicting how M. brunnesecens will

cope if their environment continues to be disturbed, and may highlight potential methods for

conservation.

Detailed studies of M. brunnescens are also of great importance to local communities in their

attempts to control damage to their land. Crop raiding has been reported in many local

agricultural areas and the problem is becoming increasingly widespread. Where farmers and

macaques occur together, the monkeys often raid crops (Heinrich, 1965, cited in Fooden

1969; in Kilner (2), 2000). The damage caused by macaques is a great source of loss in time

and money put into maintaining productive farms. It is one of the farmers greatest problems

and expenses. In an interview attended by researchers (the author included) and local farmers

at the main study site, crop raiding was described as a 24 hour problem to numerous farms in

the forest vicinity, macaques attacking during the daytime and wild pigs at night.

Preventative measures are presently employed by farmers to deter such farm intruders, but

most are ineffective and many are harmful to the animals concerned. This was experienced

8first hand in this study, when shortly before the major data collection period a farmer laid

down poison in his farm to discourage macaques from stealing his crop of bananas. Around

30 macaques died (see photograph 1). Crop raiding on his farm was not reduced by this

exercise and macaques inhabiting the area were greatly disturbed by the loss of individuals

from their troops. Improved knowledge of the species will allow better recommendations to

be made, for both reduction of damage to crops while also lessening any adverse effects these

control measures may have to the continued survival of the species.

Macaque ecological background.

Macaques are female bonded species (Wranham, 1980, van Schaik, 1989 in Gore, 2001)

whereby the females remain in their natal groups and the males emigrate. Daughters take on

the rank of their mothers and so social contact with their immediate family is the key to their

social strength (Gore, 2000). Food, mates and predation protection are the 3 key factors

concerning macaques, and of these, food is thought to be the main resource for females and

mates for males.

Macaques are active for about thirteen hours a day. They are thought to be opportunistic

frugivores, but are sometimes referred to as omnivores because they must look beyond fruits,

to insects or leaves, for protein. However, nutritional needs and amounts and types of foods

ingested by macaques are not known. The present study will therefore focus largely on the

feeding behaviour of M.brunnescens. A study of their feeding habits has been carried out

previously (Stanier, 2001) but this was fairly brief and more detailed studies are required.

There are a number of published analyses of primate feeding, many based on food

choices/selection by primates (that is Laska, 2001; McConkey et al., 2000) and others that

suggest relationships between feeding and other environmental and social factors that is

9feeding height and sex class (Grassi, 2002); and time of day (Domingo-Roura, 1999). Feeding

has implications for other behaviours too, and Glickman and Sroges (1966 in Box, 1984)

hypothesized that species which obtain their food by active searching and varied manipulation

will be more active behaviourally and differ in their patterns of responsiveness than those

which are able to harvest an easily available, plentiful supply of food with little effort.

Information on daily activity budget is useful in the overall analysis of primate behaviour and

habitat use and has been used widely in primate research. Comparisons of the proportion of

time that animals spend in different activities are important in assessing inter and intra-species

behavioural differences and may be used to identify the adaptive nature of variability in

temporal patterning of activities (Terborgh, 1983; Robinson, 1986; Kinnaird, 1990, in

OBrien and Kinnaird, 1997). Di Fiorre and Rodman (2001) researched time allocation

patterns of lowland woolly monkeys and related them to demographic, social and

environmental factors. Whitten (1983; in Di Fiorre and Rodman, 2001) suggested that primate

time budgets are influenced by factors such as age, sex, social rank, reproductive condition

and the degree of human disturbance in the region.

Relationships between feeding and activity budgets are of relevance to the present study, and

a few sources discuss these relationships. Oates (1986), in OBrien (1997), stated that diet and

habitat structure in particular, importantly affect an animals use of time because of the trade-

offs between acquisition of energy and the metabolic costs of different behaviours. It has also

been stated that in some species individual activity budgets vary seasonally in response to

changes in the abundance, quality, or distribution of important food resources (Isbell and

Young, 1993 in Di Fiore and Rodman, 2001).

10

Analysis of activity budgets are of increased importance in this study as they may be useful

for trying to quantify the damage caused by crop raiding. Therefore data on daily activity

budgets will be recorded with a number of aims and objectives in mind. The importance of

feeding information was outlined previously and this will be analysed in further detail in this

study.

Aims and objectives

1. To gain information on the time spent engaged in various activities throughout the day.

2. To discover what factors influence the proportion of time spent on the various activities

3. To determine the diet of macaques over the study period.

4. To add to the existing body of knowledge about M. brunnescens.

11

Methods and Materials

Study site

The study took place in a small

village called Kaweli, in the

Kapontori district of Buton island

(map reference S: 05 11 620; E: 122

51 350) (Kilner, 2000 (1)), south-east

Sulawesi (white arrow, figure 3). The

population of southeast Sulawesi is

predominantly Muslim, with a

density of more than 30 people km-2

and a traditional economy based on

slash and burn agriculture and

fishing ( Kilner, 2000 (1) ).

The community in Kaweli consists largely of farmers, who generally see the presence of

scientists there to be beneficial.

Beyond the village houses were a mixture of cocoa, banana, sweet potato, cashew and

coconut farms. These farms were in stark contrast to the types of large, orderly farms seen in

Europe. Farms near the study site were small plantations with crops planted in what appeared

to be a random, unorganised manner. Beyond the farms began the mixture of primary and

secondary tropical forest in which the macaques lived. At the time of the study there were 6

troops of macaques known to live in the forest surrounding the village of Kaweli.

Figure 3: Kaweli study site and surrounding area.

10 km.

10 km.

12

The forest was a difficult environment for data collection due to spontaneous, heavy rainfall;

thick vegetation in many areas (limiting visibility some of the time); and steep, uneven, rough

terrain (limestone coral) becoming slippery when it rained and sometimes causing injury or

hindering progress when following the troop.

Study animals

It was planned for work to be conducted on two troops. Unfortunately however, shortly before

commencement of data collection a local farmer placed poison in his fields, resulting in both

troops depleting in numbers. Troop 1 was the worst affected, and only a small amount of data

was therefore included in the study. The planned fruit availability analysis of troop 1s home

range was thus abandoned. The majority of the research was concentrated on troop 2.

The disruption endured by troop 1 made it impossible to precisely determine its composition

although at least three adult males and a few adult females were observed. Troop 2 comprised

five adult females, three sub-adults and three juveniles, with the adult males all lost to

poisoning. Most adult females in both troops had dependent infants but these were not

included in the study.

M. brunnescens is a medium sized primate belonging to the Cercopithecidae family. They are

hardy, intelligent primates with stout bodies about 37 to 76 cm (15 to 30 in) long, and short

powerful limbs (Rowe, 1996). Over each eye they have a prominent ridge and the muzzle is

dog-like (Rowe, 1996). Their buttocks bear a large, bare, callus patch, which for females

varies in degree of redness, depending on stage of oestrus. Unlike most of the other macaque

species, M. brunnescens does not have a tail. Other phenotypic characteristics of this macaque

species are dependant on their age/sex class. Since this class is used in the study, for the

13

purpose of identifying individuals in the troop, age/sex definitions are described below. These

descriptions were prepared before leaving to begin the study in Indonesia and were refined

following a preliminary observation week in which no data was collected:

Adult males

The largest of all the classes, with a rough mean weight estimate of ~70 kilos (Cooper, 2000).

The adult male has thick, black fur and resembles a small gorilla. It is very easily

distinguished, being well muscled and having a characteristically macho stance and walk.

When angry or signalling to members of the troop to halt or progress, the adult male makes a

clucking vocalisation that none of the other age/sex classes make.

Adult females

These are larger than juveniles but not as broad or robust as the adult male. Like all but the

infants, they have black face and hands. The pelage is blackish grey becoming a lighter grey

on the limbs and as the individuals mature. Adult females are very easily distinguished due to

their bald perineal patches that are often swollen and red; and their red, sometimes swollen

nipples.

Sub-adults

Male and female sub-adults are grouped in this study as discrimination between them can be

difficult. These are typically smaller than the adults, more wiry in conformation with a more

round-shouldered appearance. Their face and hands are black and their pelage is dark. A

pinkish perineal area, if seen, can distinguish the females from the males.

14

Juveniles

Juveniles are smaller than the sub-adults (~15-25 kilos (Cooper, 2000)) and males and

females are fairly indistinguishable as they are undeveloped sexually. Their faces may be

slightly lighter in colour than older members of the troop and they have fairly narrow

shoulders to match their slight bodies. According to Cooper (2000) juveniles have a loping

gait that contrasts with the more purposeful striding seen in older macaques. They are also

totally independent of their mothers (that is for food and travel etc).

Infants

Although their data was not included in the study, infants were visible throughout much of the

observation time. They are slightly smaller in size than the juveniles (~5-15 kilos (Cooper,

2000)) and have a sparser pelage covering. Their faces may be flesh coloured, making them

resemble small chimpanzees. They are dependent on their mothers, particularly for travel and

nutrition.

Preliminary observations

Before the period of data collection began, one preliminary week was taken. This week

allowed the observer to become familiar with the forest environment in the home range of the

studied troops, which was important for successfully following the macaques. Transect paths

were learned, areas of particularly difficult or dangerous terrain were noted, and avoiding

biting ants and stinging plants was practiced. The preliminary week also enabled the observer

to become practiced in listening for macaque calls to locate the troop, accurately

distinguishing the age/sex classes, being able to recognise when a particular behaviour is

carried out, testing precise methods of data collection and refining of age/sex class and

behaviour category descriptions. It was also important to know how close you could get to the

15

macaques to remain safe and to cause them minimal disturbance. In addition to these factors

the preliminary week helped in the habituation of the troop, particularly as troop 2 were fairly

unhabituated at first.

Data Collection

Macaque troops were followed from sleep tree to sleep tree between the hours of 05.30 h. and

17.00 h. Location of the troop was accomplished by returning to the area that the macaques

were seen settling in, the night previously. Failure to locate them using this method meant

systematically searching the whole home range and listening for the macaques distinctive

vocalisations and rustling sounds in order to pinpoint their position.

Activity Budgets

To gain information on activity budgets, instantaneous scan sampling was conducted. Scan

sampling facilitates collection of data that is evenly representative across all individuals, time

of day and season (Martin & Bateson, 2001) and has been used in the majority of primate

studies (e.g. Tweheyo and Obua, 2001). Scan samples took place at 20 minute intervals, the

length of this interval being very important for reliable data collection. Long intervals may

cause rare behaviours to be missed and intervals that are too short make data collection

difficult and mean that samples do not constitute independent measurements (Martin &

Bateson, 2001). Each scan took about 1 minute to complete and was carried out either

horizontally, alternating between left to right and right to left, or between bottom to top

and top to bottom, depending on how the troop were dispersed. This method follows that

used by Hillhar (2002), the reversal of scan direction reducing the possibility of biases.

16

During each scan the age/sex class of the visible individuals, along with the category of

behaviour they were seen performing, were recorded. Not all individuals in the troop could be

seen at every scan time, so it was not possible to record behavioural details of all individuals

in every scan. The position occupied in the forest: floor, branches, canopy or trunk, was also

noted. Grassi (2002) carried out a study, which concluded that age and sex differences of

lemurs influenced position occupied during feeding. Data on forest position of macaques may

help establish whether there are any such links between the type of behaviour and where it is

carried out, and time spent by the different age/sex classes in different forest positions.

Behavioural categories were prepared before arrival in Indonesia with the help of scientific

papers that report similar experiments (OBrien and Kinnaird, 1997; Melfi and Feistner,

2002).

Behavioural categories used were:

Locomotion: Includes walking, running, climbing and jumping (OBrien and Kinnaird, 1997;

Melfi and Feistner, 2002), when no other behaviours are apparent.

Resting: An inactive position is adopted, may include sitting, lying and standing postures

where no other behaviours are being performed. Includes sleeping and huddling in a group.

Feeding: Reaching for, manipulating, masticating, or placing food in the mouth (OBrien and

Kinnaird, 1997; Melfi and Feistner, 2002). Also includes drinking and manipulation of cheek-

pouch contents, although this was difficult to see in the field.

17

Foraging: Includes situations where attention is directed at a potential food source such as

while searching, preparing and handling food items. Also includes the manipulation of

substrates in search of potential foods (OBrien and Kinnaird, 1997; Melfi and Feistner,

2002).

Grooming: Includes self-grooming and social grooming (grooming applied by one individual

and received by another). The act of using the fingers and/or mouth to pick, stroke, or scratch

the fur. Mostly occurs while a seated position is adopted.

Playing: Includes solitary and social play and involves running, jumping, chasing, acrobatics

(that is hanging upside down), and playful fighting (distinguished from aggression by facial

expressions (Cooper, 2000).

Aggressive display: Includes displays directed by individuals at members of their troop,

members of other troops, or human observers. Commonly involves branch shaking, baring of

the teeth, taking up a characteristically aggressive stance (squatting with face and bottom in

the air (Cooper, 2000); shoulders positioned forward and upright), and actively chasing.

These behaviours may be accompanied by alarm calls and/or snarling. Also includes actual

fighting, involving biting, scratching, pawing and slapping (Cooper, 2000).

Vigilant behaviour: A watchful position is taken up, probably serving to protect the group

from predators and other macaque troops.

Other behaviours : Included urinating, defecating and any other activities not fitting into the

other categories.

18

Diet

To establish the variety of fruits, plants and insects taken by these monkeys, all occurrences

sampling1 of feeding behaviour was undertaken. This involved recording all instances where

feeding was seen, noting: 1) time of bout onset and offset (to give bout duration); 2) number

of individual participants in the feeding bout; 3) monkey minutes2 for the whole bout

duration; 4) type/species of food eaten; 5) part of the food consumed that is flesh, whole fruit

(this was achieved by direct feeding observations and sampling of discarded fruits); 6) forest

position taken up by the majority of participants during feeding bout; and 7) location of bout

that is forest or farm.

Fruits, leaves and other plants were sampled where possible, so that they could be studied,

drawn and photographed. Dried specimens were sent to the herbarium at the University of

Bogor, for identification. All foods consumed were given either local or invented names for

consistent identification over the study period.

1 This is where all occurrences of a particular behaviour are recorded at whatever time they occur. The behaviour

focused upon in this study was feeding.

2 Monkey minutes were calculated by first noting the length of time spent feeding by each macaque involved in

the bout. These individual times were then totalled to give the number of monkey minutes spent at the

feeding site altogether.

19

Data analysis

Data on activity budget and diet were entered into computer spreadsheets. Comparisons were

made between different variables with the use of pivot tables in Excel3. Activity budget data

were evaluated for the troops as a whole (age/sex classes combined) and for individual

age/sex classes, and dietary data were analysed for the whole troop only. Activity budgets

were described in terms of the percentage of observations of each behaviour, out of the total

number of observations of all behaviours, to give a proportion of all the days activities spent

in each behaviour. Diet species data was described as a percentage of all feeding bouts, that

each food species was ingested. Original spreadsheet data were sorted in various ways to

enable analysis of farm and forest activity budgets and diet; and weekly, diurnal and stratal

differences. Dietary analysis also involved grouping foods according to type, to determine the

relative importance of each type in the diet.

The statistical package Minitab was used to test the statistical significance of some of the

findings. As the data was not normal and there were mostly more than two columns of data

(that is k more than 2), the Kruskal-Wallis test for significance was applied. The Mann-

Whitney U test was also conducted in a few cases where there were just two data columns

(that is k = 2). To assess dietary diversity over the study period and for each week, the

Shannon-Wiener index of diversity was used.

3 A pivot table allows large amounts of data to be combined and compared. Rows and columns can be easily

changed and rotated to show various summaries of the source data and details for specific areas of interest can be

displayed.

20

The statistical tests described were used as they were appropriate to the form of the data

collected, and also because they were used in other similar studies thus enabling easy

comparisons to be made between studies. The Shannon-Wiener index of diversity was

successfully used by many including Yeager (1996), and the Kruskal-Wallis test and Mann-

Whitney U test have been widely used in primate studies and in particular in those pertaining

to activity budgets (Grassi, 2002; Melfi and Feistner, 2002).

21

Results

Activity budgets

A total of 2,164 behavioural observations were recorded over a 22-day scan sampling period.

The daily activity budget behaviours for the whole troop of macaques were calculated as

means of all scan sampling data (that is all study days and all age/sex classes) (Figure 4). On

average 30.86% of the daily activity budget was spent feeding, 27.41% was spent in

locomotion, 17.13% resting, 13.77% grooming, 2.81% foraging, 2.26% in aggression, 1.3%

in vigilance, 4.05% playing and 0.37% in other activities.

Age/sex class differences

As an average of all the study days, the various age/sex classes appeared to partition their

time slightly differently from each other (Figures 5, 6, 7 and 8). Feeding time increased with

age, adults devoting more of the daily budget to this behaviour than the sub-adults and

juveniles. Feeding time also seemed to differ between sex classes, for adults at least, as adult

males spent more time feeding than the adult females. The differences between the adult

male, adult female and sub-adult classes, in terms of the proportion of budget used for

feeding, were very small. However at roughly 25% of their budget, juveniles spent

considerably less time feeding than any of the other classes.

22

Figure 4: Activity budget of whole macaque troop.

Foraging, 2.81%

Grooming, 13.77%

Resting, 17.13%

Other, 0.37%

Feeding, 30.86%

Locomotion, 27.41%

Aggressive display, 2.26%

Vigillent, 1.34%Playing, 4.05%

23

Figure 5: Activity budget of adult female macaques.

, ,

Feeding, 32.83%

Locomotion, 22.01%

Grooming, 17.69%

Other, 0.44%

Playing, 0.35%Aggressive display, 2.64%

Foraging, 2.73%

Vigilant, 1.85%

Resting, 19.45%

Figure 6: Activity budget of adult male macaques.

, ,

Other, 7.69%

Playing, 0.00%

Vigilant, 11.54%Aggressive display,

0.00%

Foraging, 0.00%

Locomotion, 34.62%

Feeding, 34.62%

Resting, 3.85%

Grooming, 7.69%

24

Figure 7: Activity budget of subadult macaques.

, ,

Feeding, 32.65% Grooming, 12.24%

Foraging, 2.95%

Vigilant, 0.91%

Aggressive display, 2.49%

Resting, 19.05%

Locomotion, 28.12%

Other, 0.23%

Playing, 1.36%

Figure 8: Activity budget of juvenile macaques.

,

Other, 0.00%

,

Foraging, 2.99%

Vigilant, 0.18%

Aggressive display, 1.41%

Playing, 13.73%

Grooming, 7.39%

Resting, 11.62%

Locomotion, 37.32%

Feeding, 25.35%

25

Excluding adult males, time spent in locomotion (photograph 31) decreased with age.

Juveniles were the only class to devote the greatest proportion of their daily budget to

locomotion (~37%, Fig 8), adult males devoting only slightly less time than this (~35%, Fig

6). Adult males devoted considerably more time to locomotion than adult females so sex

appears to affect this behaviour, but with males and females grouped for the other age classes,

it is hard to tell if sex is really a determining factor.

Resting behaviour (photograph 32) is inversely proportional to locomotion, that is, where less

time is spent in locomotion, more time is spent resting. Hence, time spent resting increases

with age. Adult females and sub-adults spend almost equal time resting. Adult male resting

time appeared to be very limited (~4%). Juveniles also rest little, spending just under 90% of

their time active in other behaviours.

Once again excluding adult males, the daily budget devoted to grooming increases with age.

Adult females spent the most time grooming (~18%, Fig 5), compared with sub-adults and

juveniles that spent ~12% and ~7% respectively, grooming (Figs 7 and 8). In comparison to

adult females, adult males spend very little time grooming (~8%, Fig 6), a result more

comparable to that for juveniles.

Foraging varies very little between the age/sex classes and during scan sampling adult males

were never seen foraging.

Adult males were also not observed in aggressive behaviour during scan samples. The

macaques seen in this study spent a very small proportion of their daily budget in aggressive

displays. Most aggressive displays were observed to be carried out by adult females (~3%).

26

Sub-adults spent very slightly less time in aggressive behaviours and juveniles even less time

(~1%).

Age and sex appeared to be related to the proportion of time devoted to vigilance. Amount of

vigilant behaviour increases with age but remains only a very small part of the activity budget

(less than 2%) for all classes except adult males. At ~12% (Fig 6) and the third most prevalent

behaviour in their repertoire, they seemed to place a different level of importance on this

behaviour, compared to all other classes.

As one might expect, the juvenile class was found to spend more time playing (~14%, Fig 8)

than any of the other age/sex classes. Playing was the third most prevalent behaviour in the

juveniles repertoire. Sub-adults spent a very small part of their budget in play (1.4%, Fig 7),

adult males never played and the amount of play seen for the adult female class was

negligible.

Other behaviours increased with age, adult males exhibiting the highest value for this

category (~8%). Juveniles were never seen performing other behaviours and the amount

seen for the other 2 classes was negligible.

Despite these apparent age and sex class variations, some of which appear to be quite

substantial, the differences in daily budget partitioning of behaviours were found to be not

statistically significant (Kruskal-Wallis p = 0.990) (Table 2 (1)).

27

Table 2: Statistical tests

N Median Ave rank Z

Adult female 9 2.730 19.1 0.20 Adult male 9 7.690 17.5 -0.33 Subadult 9 7.390 18.7 0.07 Juvenile 9 2.950 18.7 0.05 Overall 36 18.5

1) Kruskal-Wallis: Test to compare age/sex class variations in activity budget.

H = 0.12 DF = 3 P = 0.990 H = 0.12 DF = 3 P = 0.990 (adjusted for ties) N Median Ave rank Z

Farm 9 4.850 9.9 0.31 Forest 9 4.070 9.1 -0.31 Overall 18 9.5

2) Kruskal-Wallis: Test to compare farm and forest variations in activity budget of all age/sex classes combined. Rank

H = 0.10 DF = 1 P = 0.757

N Median Ave rank Z

Week 1 3 0.4900 2.0 -2.50 Week 2 3 6.6700 10.7 2.31 Week 3 3 2.7200 5.0 -0.83 Week 4 3 4.8100 8.3 1.02 Overall 12 6.5

3) Kruskal-Wallis: Test to compare budget devoted by all age/sex classes combined, to foraging each week.

H = 9.97 DF = 3 P = 0.019

N Median Ave rank Z

Grooming week 1 3 6.400 2.0 -1.96 Grooming week 4 3 16.350 5.0 1.96

4) Kruskal-Wallis: Test to compare budget devoted to grooming in week 1 with that in week 4

Overall 6 3.5 H = 3.86 DF = 1 P = 0.050

N Median Ave rank Z

Feeding week 1 3 42.36 5.0 1.96 Feeding week 4 3 23.08 2.0 -1.96 Overall 6 3.5

5) Kruskal-Wallis: Test to compare budget devoted to feeding in week 1 with that in week 4.

H = 3.86 DF = 1 P = 0.050

N Median Ave rank Z

06.00-08.40 9 2.740 17.2 -0.26 09.00-11.40 9 4.400 17.2 -0.26 12.00-14.40 9 6.470 18.1 0.02 15.00-17.00 8 6.070 19.7 0.53 Overall 35 18.0

6) Kruskal-Wallis: Test to compare diurnal differences in occurrence of daily behaviours.

H = 0.32 DF = 3 P = 0.956 H = 0.32 DF = 3 P = 0.956 (adjusted for ties)

N Median Arboreal 9 34.0 Terrestrial 9 54.0 Point estimate for ETA1-ETA2 is 2.0 95.8 Percent CI for ETA1-ETA2 is (-98.0,212.0) W = 86.0

7) Mann-Whitney: Test to compare arboreal/terrestrial differences of all behaviours.

Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 1.0 Cannot reject at alpha = 0.05

28

Farm/Forest differences

On some days the macaques were found to spend time on nearby farms. The proportion of the

day spent on the farms varied between days and increased over the 4-week study period. On

quite a few occasions they were seen to spend almost the whole day there. Activity budgets

were compared for days where much time was spent on the farms and for days where most

time was spent in the forest (Figure 9).

Daily budget devoted to feeding varied substantially depending on whether most of the day

was spent on farms or in the forest. On days spent predominantly in the forest, macaque s

spent approximately 42% of their budget on feeding, compared to 29% on days spent mostly

in the farms. It appears that for forest days the macaques studied spend almost half of their

entire activity budget on feeding. Very little time was spent foraging when in the forest

however, and in comparison foraging comprised a much greater part of the daily budget on

days spent in the farms.

Time spent in locomotion and engaged in play behaviour was almost exactly equal for both

farm and forest locations. Slightly more time was devoted to resting on days spent in the

farms (~19%) compared with days spent in the forest (~16%).

At 15%, the proportion of the daily budget devoted to grooming on days spent mostly on the

farms, was over a third greater than that devoted to grooming on days in the forest.

Vigilance and aggression are not predominant behaviours, but they seemed to occur roughly

twice as often on days spent on the farms compared to days spent in the forest (Figure 9). The

occurrence of other behaviours was similarly rare, but whereas over 1% of the activity

29

budget was spent on these behaviours when in the forest, they were never seen to occur in the

farms.

Once again, these apparent differences in activity budget for all age/sex classes combined (for

days spent predominantly on farms compared to days spent predominantly in the forest),

turned out to be not statistically significant according to the test applied (Kruskal-Wallis p=

0.757) (Table 2 (2)).

Weekly changes in partitioning of the activity budget.

Differences in daily activity budget over the 4-week study period were examined for all

age/sex classes combined (Figure 10). It can be seen that the amount of aggression changed

very little over the study period, with the exception of week 2 in which no aggression was

observed during sampling.

The budget devoted to feeding decreased steadily over the 4 weeks, beginning as high as

almost 40%, falling to just over 25% in the last week. There was an overall increase in

foraging behaviour, although quite slight, and week 2 saw a particularly high level of this

behaviour. The differences in foraging over the 4 weeks were in fact significant (Kruskal-

Wallis p=0.019) (Table 2 (3)). Locomotion remained much the same over the study period

and time spent playing varied slightly, but non-uniformly over the 4 weeks. Budget devoted to

resting and vigilant behaviour changed very little, apart from a small increase in both

behaviours between weeks 1 and 4.

30

Figure 9: Variations in daily activity budget when majority of day spent on farms compared to days when most time spent in the

forest

0.00

%

1.18

%

2.21

%

4.12

%

4.85

%15.0

0%19.

41%24

.12%

29.1

2%

1.43

%

0.81

%

1.22

%4.07

%

0.41

%

8.55

%

16.2

9%

24.8

5%

42.3

6%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Feeding Locomotion Resting Grooming Foraging Playing Aggressivedisplay

Vigilant Other

Behaviour category

Pro

po

rtio

n o

f d

aily

act

ivity

bu

dg

et

Farm

Forest

Figure 10: Differences in daily activity budget from week to week over the study period.

0%

10%

20%

30%

40%

50%

Fee

ding

Loco

mot

ion

Res

ting

Gro

omin

g

Pla

ying

For

agin

g

Agg

ress

ive

disp

lay

Vig

ilant

Oth

er

Behaviour category

% o

f dai

ly b

ud

get Week 1

Week 2

Week 3

Week 4

31

Further analysis of significant weekly behavioural differences.

Grooming and feeding were the behaviours that changed most substantially over the 4-week

study period. Therefore further analyses were carried out on these behaviours.

The amount of grooming behaviour observed increased over the four weeks of study with the

most grooming seen in week 3 (Fig 10). To analyse this further, charts were created for three

of the age/sex classes (Figures 11, 12 and 13). Adult females showed a gradual increase in

grooming between weeks 1 and 4, apart from a particularly marked increase in week 3 (Fig

11). Sub-adults had a more irregular grooming pattern over the 4 weeks, varying very little in

weeks 1 and 2, then increasing almost four fold in week 3 and decreasing again slightly in

week 4 (Fig 12). Time juveniles devoted to grooming varied little over the first three weeks

and then almost doubled in week 4 (Fig 13).

The differences in activity budget proportions that adult females, sub-adults and juveniles

(combined) devoted to grooming between weeks 1 and 4 were statistically significant

(Kruskal-Wallis p= 0.050) (Table 2 (4)). Data on the males were not analysed in this case as

although contributing to information on overall daily activity budgets, there was insufficient

for reliable individual age/sex comparisons.

Feeding appeared to change markedly too. The overall differences in feeding over the four

weeks appear to be mainly due to quite a large drop in observed feeding of adult females and

sub-adults (Fig 14). Juvenile feeding decreased by roughly 10% after the first week, and

varied little for the rest of the study. A gradual decrease each week was seen in adult female

feeding over the study period, with the greatest decrease being between weeks 2 and 3 (Fig

14). At its highest in week 1, adult females devoted around 42% of their total daily activity

32

Figure 11: Proportion of daily activity budget devoted to grooming by adult females in weeks 1,2,3 and 4.

week1, 7.74%

week 2, 15.13%

week 3, 25.59%

week 4, 19.62%

Figure 12: Proportion of daily activity budget devoted to grooming by sub-adults in weeks 1,2,3 and 4.

week 1, 5.56%

week 2, 4.35%

week 3, 18.37%

week 4, 16.35%

33

Figure 13: Proportion of daily activity budget devoted to grooming by juveniles in weeks 1,2,3 and 4.

week 1, 6.40%

week 2, 4.44%

week 3, 6.21%

week 4, 11.19%

Figure 14: Proportion of daily activity budget devoted to feeding over weeks 1, 2, 3 and 4.

0%

10%

20%

30%

40%

50%

Adult female Sub-adult Juvenile

Age/sex class

Pro

po

rtio

n o

f act

ivit

y b

ud

get

sp

ent f

eed

ing Week 1

Week 2Week 3Week 4

34

budget to feeding behaviour. Sub-adults devoted a similarly large proportion of their budget

to feeding during week 1. Again, this was substantially reduced by week 4, but week 3 saw a

high level of feeding (over 30%) in comparison to the other two age/sex classes in that week.

Statistical analysis of daily budget devoted to feeding by the three age/sex classes between

weeks 1 and 4, shows that the weekly differences observed are statistically significant

(Kruskal-Wallis p=0.050) (Table 2 (5)).

Diurnal differences.

It was observed while in the field that some activities occurred more frequently at certain

times throughout the day. Graphs were created to examine this further (Figs 15 to 22). For

each behaviour category, a percentage of the daily occurrence total for that behaviour at

each time throughout the day, for all the study days, was plotted. Locomotion seems to be

fairly evenly spread throughout the day, values only ranging between 1% and 6% for every

20-minute time division (Figure 15). However there do seem to be two slight peaks in

locomotion, the first between 07.00 and 10.00 h. and the second between approximately 15.00

and 16.00 h. There is a fairly rapid increase between 06.00 and 07.00 h; and at the end of the

day after 16.30h locomotion decreases quite quickly. Between 11.00 and 14.00 h., locomotion

remains fairly low compared with at other times of day.

Resting behaviour is much less constant throughout the day than locomotion (Figure 16).

Between 06.00 and 08.00 h. there is a large resting peak when the macaques spent much of

their daily resting budget. There was also quite a long resting period between 12.00 and 14.00

h. Resting occurred in relatively short, small bouts throughout the rest of the day. During the

afternoon the peak in resting behaviour coincided with the drop in locomotion.

35

Figure 15: Allocation of locomotive time throughout the day.

0%

1%

2%

3%

4%

5%

6%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f lo

com

oti

ve o

bse

rvat

ion

s oc

curr

ing

by t

ime

of d

ay.

Figure 16: Allocation of resting time throughout the day.

0%

1%

2%

3%

4%

5%

6%

7%

8%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f re

stin

g o

bse

rvat

ion

s o

ccu

rrin

g

by

tim

e o

f day

.

Figure 17: Allocation of grooming time throughout the day.

0%

1%

2%

3%

4%

5%

6%

7%

8%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f g

roo

min

g o

bse

rvat

ion

s oc

curr

ing

by t

ime

of d

ay.

36

Grooming takes place in bouts throughout the day and never ceases completely (Figure 17).

The amplitude of the bouts decreases progressively during the course of the day, indicating a

decrease in grooming behaviour. The highest proportion of grooming is seen between 07.00 h.

and 08.00 h. Another peak in grooming occurs between 13.00 h. and 14.00 h.

Play behaviour occurs in definite bouts and unlike locomotion, resting and grooming, is not

carried out continually throughout the day. Between about 10.40 h and 15.00 h play behaviour

is at its highest for the day (Figure 18). Several large playing bouts appear to occur within this

time, and coincide with a peak in grooming behaviour between 13.00 and 14.00 h.

With the exception of the start and the end of the day, feeding behaviour never ceases for the

whole of the day (Figure 19). The distribution of feeding occurrences are quite even

throughout the day, once again occurring in a bout-like fashion. Feeding is at its lowest

between 12.30 and 14.00 h.. Foraging patterns are quite different to this, with only a few long

bouts occurring at various points during the day (Figure 20). The largest proportion of daily

foraging behaviour occurs between 09.30 h and 12.00 h and between 15.20 h and 16.20 h.

Almost 30% of all foraging occurs at these two times.

The bout-like pattern of behavioural occurrences is very evident in the aggressive behaviour

category (Figure 21). All aggressive occurrences happen in fairly short-lived bouts that then

cease altogether until the next time. Little aggression is seen in the early morning until about

10.40 h, after which time four large bouts occur. The largest proportion of daily aggressive

behaviour was seen between the hours of 12.00 and 15.00 h.

37

Figure 18: Allocation of playing time throughout the day.

0%

2%

4%

6%

8%

10%

12%

06:00

07:00

08:00

09:00

10:00

11:00

12:00

13:00

14:00

15:00

16:00

17:00

Time of day.

% o

f p

layi

ng

ob

serv

atio

ns

occ

urr

ing

by

tim

e o

f d

ay.

Figure 19: Allocation of feeding time throughout the day.

0%

1%

2%

3%

4%

5%

6%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f fe

edin

g o

bse

rvat

ion

s o

ccu

rrin

g b

y tim

e o

f d

ay.

Figure 20: Allocation of foraging time throughout the day.

0%

2%

4%

6%

8%

10%

12%

14%

16%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f fo

rag

ing

ob

serv

atio

ns

occ

urr

ing

by

time

of

day

.

38

Figure 21: Allocation of aggressive time throughout the day.

0%2%4%6%8%

10%12%14%16%18%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day.

% o

f ag

gres

sive

obs

erva

tions

o

ccu

rrin

g b

y ti

me

of

day

.

Figure 22: Allocation of vigilant time throughout the day.

0%

2%4%6%

8%10%

12%14%

16%

06:00

06:40

07:20

08:00

08:40

09:20

10:00

10:40

11:20

12:00

12:40

13:20

14:00

14:40

15:20

16:00

16:40

Time of day

% o

f vi

gila

nt

ob

serv

atio

ns

occ

urr

ing

by

tim

e o

f d

ay.

39

A similar pattern of few large bouts is seen for daily vigilant behaviour (Figure 22). Most of

this behaviour is seen during the morning between the hours of 06.30 and 10.30 during which

time around 50% of daily vigilant behaviour takes place. After 11.30 h. vigilant behaviour

occurred at a low level (although still in bout-like form) until around 16.00 h. At no point

during the study period was any vigilance to be seen during the hour between 10.30 h. and

11.30 h.

Feeding and locomotion are the most evenly spread behaviours throughout the day. Grooming

and resting occur to some degree at all times but they show a more pronounced bout-pattern.

Play and foraging occur throughout much of the day again in a bout-like fashion, but the level

returns to zero before more of this behaviour takes place. Vigilance and aggression occur the

least frequently of all the behaviours, with just a few peaks daily.

Despite these observed variations in the timing of behaviours throughout the day, the

differences appear not statistically significant (Kruskal-Wallis p=0.956) (Table 2 (6)).

Stratal position.

Macaques were observed to carry out daily behaviours throughout the different stratal levels.

Time was spent terrestrially: on the floor and on fallen trees; and arboreally: on branches, on

the tree trunks and in the canopy. There appears to be no terrestrial or arboreal bias for the

practice of either aggressive displays or grooming bouts (Figure 23). Almost 200 more

feeding observations were made while macaques were arboreally situated compared with

when terrestrial. Approximately one third less time was spent in locomotion terrestrially than

arboreally. Play behaviour took place roughly 1.5 times more terrestrially than arboreally.

Less than a fifth of all observed foraging occurred arboreally as this behaviour mostly took

40

Figure 23: Number of observations of various behaviours in different strata.

0

100

200

300

400

500

600

700

800

Loco

motion

Feed

ing

Groo

ming

Restin

gPla

ying

Forag

ing

Aggre

ssive

displa

yVig

illent

Othe

r

Behaviour category

Cou

nt o

f ob

serv

atio

ns. Arboreal

Terrestrial

41

place while the macaques were foraging for sweet potato on the ground. Over twice as many

arboreal observations of resting were made compared with observations of this behaviour

terrestrially. Similarly, there are almost twice as many arboreal counts of vigilance compared

with terrestrial counts. Three times as many other behaviours occurred terrestrially in

comparison to those occurring arboreally.

The largest arboreal/terrestrial differences were seen in foraging and resting behaviour

categories.

Once again, despite apparent differences between arboreal and terrestrial counts for each

behaviour category, these are not statistically significant (Mann-Whitney p=1.0) (Table 2 (7)).

Macaque diet

During all-observations sampling of feeding behaviour, 253 feeding bouts were observed.

Macaques were seen ingesting a total of 50 types of food over the study period (Table

3)(photographs 1-14) and of these, approximately 24 have not previously been identified in

the diet of macaques. The same 50 types were also observed ingested during scan sampling.

33 of the 50 foods were fruits; 10 were stems and flowers; another 6 types were leaves of

various fruits and the remaining food type was insects. 12 of the 50 food types were farm

crops, the remaining foods being derived from the forest. Most foods that the monkeys were

seen consuming were identified (given local names as a minimum). However a few types of

leaves that were seen ingested could not be observed closely enough for identification, also

one fruit, one crop and two flower species remained unidentified.

42

Scientific name (family or species) Food type/species. Fruit Leaves Flower Stem,stalk Farm crop

Arumba xAsam x

Tamarindus indicus Bamboo xMusa sapientuml Bananas x x

Bangkudu xMorindu citrifolia Cashews x xTheobroma cacao Cocoa x x

Cocoa leaves x xCocos nucifera Coconut x xRubiaceae coffea Coffee x x

Maize x xDahu x

Davi Davi xPangi x

Pangi leaves xGamal x x

Green crab apples xGreen limes xJambo biji x

Kapok x xKase x

Pommetica pinata Kedongdong Hutan xKetapan x xKonau xLeaves x

Palahutan xPaper lanterns x

Puajo xLantana camara Rambutan hutan x

Red berry chanderliers xRed tomato berries x

Rhubarb stalks xSirahutan x

Averrhoea carambola L. Starfruit x xSaccharum officinarum Sugarcane xIpomoea batatas L. Sweet potato x x

Talihutan xTiny green figs xTokulu leaves x

Unidentified farm crop (stalks) x xUnidentified red berry bunches x

Unidentified small flowery berries xUnidentified tiny flower bunches x

Warung xHibiscus tiliaceus White Berry fig x

White stem flowers xYellow grape x

Yellow Grapefruit xYoung Bau leaves x

Insects

Table 3: Identified macaque foods

43

Fruit photographs: All taken by K. Andrews (2002).

5 cm

Photograph 1: Bangkudu fruit.

10 cm.

Photograph 2: Bangkudu.

Photograph 9: Davi davi. Photograph 8: Green crab apple.

Photograph 7: Konau.

5 cm.

5 cm.

Photograph 3: Asam. Photograph 4 : Arumba.

Photograph 5: Cocoa. Photograph 6: Kase.

10 cm

5 cm.

5 cm.

3 cm.

4 cm.

44

5 cm.

Photograph 13: Dahu Photograph 14: Talihutan.

Photograph 12: Little green limes. Photograph 10: Tiny green figs.

2 cm.

2.5 cm.

3 cm.

Photograph 11: Yellow grapefruit

45

Photograph 16: Banana tree. Photograph 17: Dahu growingfrom the tree.

Photograph 18: Remnants of maize, post crop-raid. Photograph 19: Remnants of dahu after feeding bout.

Photograph 20: Coffee. Photograph 21: A cocoa plantation.

Photograph 15: Davi davi growing onthe tree trunk.

46

To assess the importance of each food observed in the diet of macaques, the number of

monkey feeding minutes devoted to each one was calculated and described as a percentage of

the total monkey feeding minutes spent on all species. Of the 50 identified food types, there

were five species that contributed the most to the overall macaque diet over the study period.

68.01% of all feeding minutes were devoted to these five species combined (Figure 24).

Macaques fed on white berry fig 20.56% of the feeding time, sweet potato 17.96%, cocoa

10.02%, bananas 9.77% and kapok 9.70% of the feeding time. Three of these top five foods

were farm crops, to which monkeys devoted over a third (37.75%) of their feeding time over

the whole study period. The rest of the diet was formed of progressively smaller contributions

(between 4% and 0.01%) by the rest of the 45 food types (Figure 24).

Dietary diversity

The diet of macaques was diverse (Table 4), having a Shannon-Wiener index of 1.17 for the

whole study period. However this diversity varied from week to week during the study. Week

1 had the lowest index (Shannon-Wiener 0.45), one food species alone contributing 67.82% to

the weekly total. The number of identified species/types used as food sources per week of the

study period also varied, and ranged from 17 to 28. Despite ingesting the fewest different

species (17 species), dietary diversity was highest in week 2 (0.76) compared to the other

weeks. There was quite a substantial increase in the number of foods ingested in weeks 3 and

4 (28 and 32 respectively). However despite this, diet diversity varied little from that

established previously in week 2. The data showed that although fewer food types were

consumed in week 2, each one contributed more equally to that weeks total feeding,

compared to other weeks, where macaques fed on many species but concentrated the majority

of their time on just 1 or 2 different species.

47

Figure 24: Proportion of feeding time devoted to different food types/species.

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%W

hite

Ber

ry fi

gS

wee

t pot

ato

Coc

oaB

anan

as

Kap

okP

angi

Pap

er la

nter

nsLe

aves

Inse

cts

Ram

buta

n hu

tan

Cas

hew

sR

ed b

erry

cha

nder

liers

Mai

zeC

offe

eP

uajo

Red

tom

ato

berr

ies

Dah

uA

sam

Bam

boo

Sira

huta

nK

edon

gdon

g H

utan

Pal

ahut

an

unid

entif

ied

red

berr

y bu

nche

sG

amal

Ket

apan

Coc

oa le

aves

Pan

gi le

aves

Dav

i Dav

iU

nide

ntifi

ed ti

ny fl

ower

bun

ches

Tin

y gr

een

figs

Yel

low

Gra

pefr

uit

Whi

te s

tem

flow

ers

Gre

en li

mes

star

frui

tA

rum

baG

reen

cra

b ap

ples

Kas

e

Sug

arca

neT

alih

utan

Tok

ulu

leav

esY

oung

Bau

leav

esR

huba

rb s

talk

sY

ello

w g

rape

Kon

auun

iden

tifie

d fa

rm c

rop

(sta

lks)

jam

bo b

ijiW

arun

g

Ban

gkud

uun

iden

tifie

d sm

all f

low

ery

berr

ies

Coc

onut

Food type/species.

% o

f all

mo

nke

y fe

edin

g m

inu

tes.

? Farm/crop species

? Forest/wild species

48

Table 4: Dietary diversity for the study period and for individual study weeks.

Number of food types ingested.

Shannon-Weiner index of diversity.

Whole study period 52 1.17

Week 1 18 0.45

Week 2 17 0.76

Week 3 28 0.72

Week 4 32 0.74

49

Weekly food species variation.

Macaques spent most of their weekly feeding time on different species in different weeks. For

example, in week 1 white berry fig was the preferred food type, in week 2 most feeding time

was devoted to banana consumption and in weeks 3 and 4 the preferred species was sweet

potato. Food species patterns in the macaque diet are highly changeable if it is considered that

although white berry fig is preferred in week 1, it does not appear at all in the diet in week 2.

Similarly, despite being the species of preference in week 2 (29.77%), contribution of bananas

in weeks 3 and 4 decreases substantially to less than 3.5% in week 4.

Food groups.

Each of the species identified as macaque foods fall into one of several categories of food

such as fruit, leaves, stems, shoots, flowers and invertebrates. The composition of the diet in

terms of these different food groups is described in figure 25. Macaques spent the largest

portion of their feeding time eating wild fruits (47.91%) and just slightly less than this eating

farm crops (43.93%). Leaves, invertebrates, stems and shoots, and flowers constituted roughly

4%, 2.2%, 1.1% and 0.8% of the feeding time, respectively. If it is considered that a large

majority (42.49%) of the time devoted to crops, is spent eating foods belonging to the fruit

food group, it can be said that 90.4% of monkey feeding time is spent eating fruits. Therefore

according to this study M. brunnescens is a frugivorous feeder.

Although fruit ripeness was not assessed quantitatively in this study, fruits generally appeared

to be ripe and fleshy (as in Yeager, 1996). The leaves consumed were largely young, floppy

and succulent.

50

Weekly food group variation.

The level of contribution of these food groups to the overall diet varied over the four weeks

of the study (Figure 26). Providing by far the majority of the diet in all weeks (more than

85%), are foods from the fruit group. This once again reinforces evidence gained that these

macaques are frugivorous, since despite weekly changes in food species ingestion, fruits

always predominate. Despite eating a greater range of fruits throughout the course of the

study period (Table 4), the contribution of fruits to the diet decreases slightly over the 4

weeks. During weeks 1 to 3 time spent ingesting invertebrates decreases by roughly 0.5 each

week. Invertebrate feeding is highest in week 4, macaques devoting almost twice as much

time to their consumption than they did in week 1 (Figure 26). Contribution of leaves to the

diet varies over the study period too. There is an increase in time spent eating leaves between

weeks 1 and 4, time spent in week 3 being particularly high and almost double the values for

any of the other weeks (Figure 26). Flowers are eaten in weeks 1, 2 and 3. Time spent eating

flowers is negligible in week 1 and greatest of all the weeks in week 2 (2.83%). Stems and

shoots form a negligible part of the diet in weeks 1 and 3, and increase in dietary importance

in week 4 (3.25%) (Figure 26).

Over the study period there is a general decrease in time spent consuming foods from the fruit

group and an increase in consumption from one or more of the other food groups, to

compensate for this.

Feeding height (stratal position).

Feeding took place throughout the forest and farms, in various positions. These positions were

categorised as floor, fallen trees, branches, canopy and trunk. The position taken up during

feeding bouts depended mainly on the type of food being pursued and on the way it grew

51

Figure 25: Proportion of macaque feeding on different food groups.

Flowers, 0.84%Stems+shoots,

1.12%

Crops, 43.93%

Invertebrates, 2.22%

Wild fruits, 47.91%

Leaves, 3.98%

Figure 26: Proportion contribution of different food groups to total feeding over the 4 study weeks.

40

50

60

70

80

90

100

wk1 wk2 wk3 wk4

Week of study.

% o

f wee

kly

feed

ing

tota

l. stems+shoots

flowers

leaves

invertebrates

fruit

52

(photographs 15-17 and 20-21). To see the proportions of feeding time spent arboreally and

terrestrially, floor and fallen trees were grouped as terrestrial positions, and branches, canopy

and trunk were grouped as arboreal positions. Although height use can be investigated in

more detail using height intervals (Grassi, 2002), distinguishing (in the field) between

positions within the above-described groups may have been inaccurate, and simplifying into

arboreal and terrestrial descriptions hence seemed necessary. Time spent terrestrially was

41% lower than time spent arboreally (Figure 27), for feeding over the entire study period.

Observations in the field suggest that the value for time spent terrestrially would be higher for

time spent only on the farms (that is excluding forest values) over the study period as the

macaques spent much of their time terrestrially while feeding on sweet potatoes, when in

farms.

Group size during bouts.

Macaques fed in bouts of various lengths, intermittently throughout the day. Bouts usually

involved one, several, or all individuals of a troop. The numbers involved in the bout

appeared to depend on the type of food being pursued, some food species inducing more

large-group feeding bouts than other foods (Figure 28). The food inducing the highest

proportion of large-group feeding bouts was sweet potato. Here, 71.4% of all bouts of sweet

potato feeding involved 9 or more individuals. Bananas, kapok, cocoa, white berry fig and

pangi induced the next highest proportions of large group feeding bouts, respectively (Figure

28).

53

Figure 27: Macaque feeding time spent arboreal vs terrestrial.

6666

3955

0

1000

2000

3000

4000

5000

6000

7000

Terrestrial Arboreal

forest position

Co

un

t o

f m

on

key

feed

ing

min

ute

s.

Figure 28: Food species which attracted the most occurances of large group feeding bouts.

01020304050607080

Sweetpotato

Bananas Kapok Cocoa WhiteBerry Fig

Pangi

Food species.

% o

f al

l bo

uts

of

each

fo

od

sp

ecie

s in

volv

ing

9 or

mor

e m

on

keys

.

54

Crop Raiding.

Crop raiding (shown in photographs 23-29) occurred on 62.5% of the study days. Of the

entire crop raiding occurring over the study, only 0.05% of it occurred in week 1 (Figure 29).

This increased to ~13% in week 2, ~47% in week 3 (when the majority of this behaviour was

seen) and ~40% in week 4.

Different food species were consumed in varying amounts while macaques were on the farms,

the most frequently taken species being sweet potato (Figure 30). Some wild foods could be

found in the vicinity of the farms and these were sometimes targeted.

During a crop raid macaques fed intensively for a few minutes to a few hours in one bout.

Macaques were more conspicuous at some times than at others during crop raiding. On

occasions they were observed collecting large amounts of crop foods from the field and

carrying them in their arms and cheek pouches, back to the protection of the foliage

surrounding the field, where they could then feed with less risk of being seen. At other times

they seemed unaware of any possible dangers of feeding in the farms, sitting in open spaces

blatantly feeding on surrounding crops. During the study period attempts by farmers to

frighten off crop-raiding macaques, were observed. The methods seen were throwing stones

and/or mud, shaking buckets full of stones, setting-off a dog in the monkeys direction,

patrolling of the crop fields by a farmer, shouting and chasing by the farmer. Of all the

methods the macaques seemed most frightened by the dog but they managed to avoid being

driven out of the farms by climbing up the nearest tree to safety. They stayed here until the

dog left the area, and then they returned to feeding. Hence most methods simply resulted in

the troop moving to a different part of the farm.

55

Figure 29: Division of farm feeding time over the study period.

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

22%

24%

26%

28%

30%

32%

34%

36%

38%

40%

42%

44%

46%

48%

50%

Week 1 Week 2 Week 3 Week 4

Week of study.

% o

f to

tal f

eed

ing

tim

e sp

ent

on

far

ms.

56

Figure 30: Foods macaques devoted most time to during crop raids.

0%

5%

10%

15%

20%

25%

30%

35%

Swee

t Pota

toCo

coa

Bana

nas

Kapo

k

Cashe

ws

Corn

on the

cob

Coffee

Gama

l

Ketap

an

Cocoa

leaves

starfru

it

unide

ntified

farm

crop

(stalk

s) Coco

nut

Wild f

oods

Crop eaten.

% t

ime

of

all f

oo

ds

eate

n d

uri

ng

cro

p r

aid

s.

57

Food manipulation.

Macaques handled different food types and species differently. Many foods such as white

berry fig, puajo, kase, dahu, yellow grapefruit and starfruit were consumed wholly, thus

allowing a large quantity of fruit matter to be eaten in a short space of time. However, the

macaques discarded the skins of fruits such as kapok, sirahutan, arumba, coffee, sweet potato

and banana, before ingesting them.

Macaques seemed to use various techniques for removing the unwanted part of the fruit from

the desired part. There were two observed methods for removal of skin, depending on the fruit

involved. In the case of bananas and sweet potato the skin was first removed, using hands and

mouth respectively. For sirahutan and coffee the whole fruit was placed in the mouth and the

insides were squeezed out and eaten, before the skin was spat out.

Manipulation of sweet potatoes was quite complex and involved digging down into the earth

to retrieve tubers, then rolling them between the hands to remove dirt, and using the teeth to

bite off the unwanted layer of skin (photographs 24-26). Cocoa handling was different, being

bitten into to break it (usually in half) and then each half being held in the hands while the

insides were scooped out by the mouth and eaten. Pangi is quite a complex food in terms of

its structure and the macaques discarded both the outer skin and the inner stones, eating only

the fleshy bit between the two parts. These were prepared for consuming in a similar way to

cocoa. Small seeds inside fruits were usually ingested along with the flesh, but for fruits such

as the red tomato berries, the centre pip was spat out.

Macaques appeared to be very wasteful with food and this was most apparent while feeding in

cocoa farms. However it was later observed that following the breaking open of a cocoa pod

58

by one individual, which consumed only a little of it and then discarded it, another individual

(usually a younger one) would follow shortly after and finish the remains that were left by the

first. This behaviour appeared to occur between parents and offspring and something similar

was seen while maize feeding (photograph 18).

Invertebrates were consumed by picking them up from trunks and branches with fingers and

quickly placing them in the mouth and also by the licking of leaves from the ground and on

trees. Rotten logs and leaf litter were particularly good sources of invertebrate prey, the

former appearing to provide a particularly good supply of termites.

Other observations

Agonistic interactions

Close observation revealed possible causes for arguments between troop members. For most

of the study period 2 members of troop 2 were seen squabbling over another juvenile. It also

appeared that some fights broke out when adult females intervened in juvenile playing bouts.

This intervention seemed to aggravate one or more other females causing a fight to break out

between parents of the playing juveniles. Macaques were quite aggressive towards each other

and at these times they were very vocal. Several large intra-group fights were observed, one

of which appeared to leave an old grey female belonging to troop 2 injured. Of the disputes in

troop 2, many involved this individual who appeared to be at the top of the pecking order.

One morning close to the end of the study period, revealed several juveniles with severe

wounds. The troop was very inactive that morning, remaining at the sleep site until about

10.00 h.. This was very unusual. Closer inspection revealed one juvenile with a severed hind

leg (which was almost falling off) and one juvenile with a not so severe wound on its forearm.

59

Both macaques had extreme difficulties with locomotion, the former painfully dragging the

weight of its leg on the floor behind it and the latter running on just its two hind legs, while

holding its injured arm with its other forearm, as if to provide a sling. On observation of other

troop members it appeared that the injured individuals were getting looked after (groomed

and food delivered to them) by adult females.

Sleep trees

Sleep trees used by the study groups tended to be tall with wide canopies and lots of branches

(photographs 33 and 34). They provided good vantage points and were often adjacent to crop

fields raided by the macaques. The troops that were observed had unusual sleep tree patterns

over the study period, in that they used different trees nearly every night and not all of these

were identified. One of troop 2s sleep trees was the white berry fig tree they spent lots of

time feeding in. This tree had all the qualities listed above, was leafy, and had the added

bonus of an immediate food source. Troop 2 also used a kapok tree that was situated in the

middle of several adjoining farms, exposing them to the risk of sightings and attack. Both the

white berry fig and kapok tree were used as sleep trees on more than one occasion over the

study.

A few of the sleep sites identified consisted of large fallen trees which formed areas filled

with scattered branches, providing shade, suitable surfaces to sit on, and a readily available

supply of invertebrates, notably ants and termites (Photograph 34). Although some sleep trees

had dense leaf covered canopies, others were leafless and left the macaques quite

conspicuous.

60

Macaque Photographs: All taken by Andrews (2002).

Photograph 22: Results of the poisoning: adecomposing monkey body which was probably amember of troop 2.

Photograph 23: Macaques contemplate raiding a sweetpotato farm

Photograph 24: A macaque sitting in a farm, scoopingthe centre out of a cocoa fruit.

61

Photograph 25: Adult female remains vigilant during acrop raid.

Photograph 26: Sub-adult foraging for sweetpotatoes .

Photograph 27 (left): Macaques in a farm, feeding on Bananas fromthe tree trunk.

Photograph 28 (above): Macaque feeding on Gamal at sides of farm.

Photograph 29: An adult female in oestrus (red bottom),and showing vigilance while crop raiding. Photograph 30: Macaque travelling in the forest.

62

Photograph 31: A macaque in locomotion in a kapok tree.

Photograph 32: Macaques resting together on a farm log,late in the afternoon.

Photograph 33: Macaques of troop 2 resting at one of theirmany sleep trees

Photograph 34: Social grooming at a fallen-tree sleep site.

63

Photograph 35: Farm fencing wasoften constructed from lines of gamal.

Photograph 36: A farm shelter designed for farmers to survey their fields; also used by us to observecrop raiding macaques.

64

Discussion

Activity budgets

Results relating to the daily activity budget of the group as a whole, contrast slightly with the

few previous studies that exist on M. brunnescens. A study by Cooper (2001) showed a much

higher estimation of time spent in locomotion throughout the day (45%), locomotion being

the activity taking up the largest chunk of the daily time budget. Instead, it was feeding that

took up the most time in the present study. Coopers study group had a much-reduced feeding

budget in comparison (10%). These differences could be due to different sampling techniques

(Cooper sampled every 4 minutes), slight differences in time of year that the study periods fell

on, or could be due to other reasons such as the fact that each study focused on different

troops, and in particular, that the present study was based predominantly on an all female

group. The latter is a plausible cause for the reduction in locomotion in the present study,

relative to the study taking place the year before (Cooper, 2001), since males are leaders of

macaque groups (Groves, 1980; Lindburg, 1977; in Cooper, 2001) and it is possible that their

absence may have led to a slower daily progression of the group around the home range.

Adult females attach high importance to feeding and without a male to move them on, they

may have continued to feed and ceased to move on as much.

Inter-group differences are inevitable since troops have different home ranges so will

undoubtedly encounter habitat differences that necessitate different spending of behavioural

budgets. OBrien and Kinnaird (1997) made similar findings suggesting that group

differences in activity budgets can often be attributed to gross habitat differences. Such

differences may concern factors such as food availability and distribution, sleep tree

distribution, and proximity of farms; and the main effect will be to alter travelling distances

65

and foraging/feeding times. Previous studies have found inter-group differences attributable

to food abundance (Kinnaird, 1990 in OBrien and Kinnaird, 1997) and to differences in

proportions of primary and secondary forest (OBrien and Kinnaird, 1997). Both factors are

likely to apply in the case of M.brunnescens, the latter factor since logging takes place in the

forest these monkeys inhabit. Time budget differences caused by inter-habitat variation in

resource availability were also reported for M. sylvanus (Menard and Vallet, 1997). Intra

s