Bonnet Macaque

The Bonnet Macaque (Macaca radiata) is a macaque endemic to southern India. Its distribution is limited by Indian Ocean on three sides and Godavari and Tapti River along with a related competing species of Rhesus Macaque in the north. This Old World monkey is a diurnal animal.

Appearance

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 exist as commensal to human, feeding on human given food and raiding on crops and houses. Two subspecies of Bonnet Macaques have been identified: Macaca radiata radiata and Macaca radiata diluta.

Dominance and Hierarchies

Bonnet Macaque seen in Nelliampathi mountains in Kerala, south India 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 non overlapping or non mixing type. Usually males are dominant over females, but its not always so. The females have a stable dominance hierarchy, which changes very rarely. While the dominance hierarchy of males is very dynamic, there is always a competition to rise in hierarchy and there is always a fight between close ranks. A male has the best chance of a high rank in his prime age which results into the highest reproductive benefit. High rank individual has first access to breeding females, females are receptive only during a few months in a year and so this result into competition between males and thus the rank which has been established by aggressive encounters come into play. Most of these aggressive encounters are basically a mock show to access other individuals but when similarly build or similarly aggressive males compete its results into brutal and sometime fatal fights. Various males may employ various means to rise in rank. Coalition formation between unrelated males to ousted a more dominant male has also been observed. Males are always moving from one troop to another to gain higher rank and the resulting benefits. But a few cases of some males staying back in a troop and becoming a dominant male of the troop has also been observed. In case of female the stable dominance hierarchy is because of female philopatry. Philopatry is a term used to define the behavior of females to stay in the troop they are born into. Females in Macaque societies rarely leave the troop they are born in. This result into formation of matrilines i.e a grouping of closely related females. These matrilines help each other during agonistic interactions. As the matrilines keep getting 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 very depleted due to few female births. Male infants would not help to reinforce the matrilines as they will be moving 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. It also has some distinct alarm calls for predators. It shows a wide variety of behaviors during various kinds of interaction ranging from affilitive, aggressive or dominance to sexual to play. "Grimace" is the most common submission or fear gesture which a subordinate shows to a dominant individual during aggressive encounters. "Grimace" is pulling back of upper lip showing the upper teeths.