This Old World monkey is a diurnal animal. It is 35-60 cm long plus a tail of 35-68 cm. Males weigh 5.5 to 9 kg., females 3.5 to 4.5 kg. It can live more than 30 years.
The Bonnet Macaque feeds on fruits, nuts, seeds, flowers, invertebrates and cereals. In southern India this macaque exists as commensal to humans, feeding on food given by humans and raiding crops and houses.
Two subspecies of Bonnet Macaques have been identified: Macaca radiata radiata and Macaca radiata diluta.
Dominance and Hierarchies
The Bonnet Macaque, like other macaques, share a dominance hierarchy which is linear. It means that there is an 'alpha' male who is the most dominant male of the troop, followed by a 'beta' male and 'gamma' and so on according to their dominance. Similarly for females also there is an 'alpha' female, 'beta' female 'gamma' female etc. The male and female hierarchies are different and of a non overlapping or non mixing type. Usually males are dominant over females, but this is not always so.
The females have a stable dominance hierarchy, which changes very rarely, whilst the dominance hierarchy of males is very dynamic. In the male hierarchy there is always a competition to rise in rank with fights between close ranks common. A male has the best chance of obtaining high rank in his prime age resulting in the greatest benefits to reproduction. High rank individuals have first access to breeding females. Females are receptive during only a few months in a year resulting in competition between males. In this situation the rank which has been established by aggressive encounters come into play. Most of these aggressive encounters are easily resolved however when similarly built or similarly aggressive males compete its results into brutal and sometime fatal fights. Different males may employ various means to rise in rank. Coalition formation between unrelated males to oust a more dominant male has been observed. Males often move from troop to troop to gain higher rank with the resulting benefits. However there have been cases observed when a male remains in a single troop, rising to become dominant male of that troop.
In the case of females the stable dominance hierarchy is a result of female philopatry. Philopatry indicates that individuals tend to remain with the troop that they are born into. This results in the formation of matrilines, groupings of closely related females. These matrilines help each other during antagonistic interactions. As the matrilines are continuously reinforced with new births of females in a troop there is rarely any upturning of ranks. There are a few rare cases of rank reversal for females in which matrilines have become extremely depleted due to few female births. Male infants would not help to reinforce the matrilines as they move off to new troops leaving their natal troops.
Behavior
The Bonnet Macaque has a very wide range of gestures and behavior which can be easily differentiated. 'Lip smacking' is one of the most common and affiliative behavior, where one individual may open and close the mouth in rapid succession with tongue in between teeth and lips pressing against each other giving an audible sound. "Grimace" is the most common gesture of fear or submission in which a subordinate shows to a dominant individual during aggressive encounters. It consists of pulling back of the upper lip showing the upper teeth. They also have distinct alarm calls for predators.
