Macaca radiatabonnet macaque

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Geographic Range

Habitat

Bonnet macaques are found in a variety of habitats, including evergreen high forest and dry deciduous forest of the Western Ghat Mountains. They are highly arboreal and are strong swimmers. They often wander onto dry prairies, although it is not their preferred habitat. Bonnet macaques coexist with several primate species, including Nilgiri langurs (or hooded leaf monkeys Trachypithecus johnii), lion-tailed macaques (Macaca silenus), and Hanuman langurs (Semnopithecus entellus). (Dewar, et al., 1989; Johnson, et al., 2007; Sugiyama, 1971)

Bonnet macaques live as commensals with humans and are most abundant on the outskirts of human settlements. In those areas they rely on trash and food generated by villagers and visitors. They are often found sleeping and eating in large Ficus trees which line roads near human settlements. (Dewar, et al., 1989; Johnson, et al., 2007; Sugiyama, 1971)

Physical Description

There are two distinct subspecies recognized: dark-bellied bonnet macaques (Macaca radiata radiata) and pale-bellied bonnet macaques (Macaca radiata diluta). As their common name suggests, bonnet macaques have a whirl of hair radiating from the center of the head. They are grayish brown or golden brown in color. They have hairless faces, which appear pink in the females. (Dunbar and Badam, 2000; Fleagle, 1999; Johnson, et al., 2007; Sugiyama, 1971)

  • Sexual Dimorphism
  • male larger
  • Range mass
    3.9 Kg (female) to 6.7 Kg (male) g
    to oz
  • Range length
    35 to 60 excluding tail cm
    13.78 to in

Reproduction

Bonnet macaques live in multi-male multi-female groups. Group ranking is linear, with older individuals being more dominant. Females are philopatric, while males disperse to other social groups. There is period in which juvenile males are solitary, as in Japanese and rhesus macaques. Bonnet macaque males form unique bonds. Dominant males tolerate the sexual activity of young males, who begin sexual interactions at 2 years old and are able to mate at age 3. Evidence suggests that young males are primarily partnered with young or sub-dominant females. However, adult and adolescent males are equally sexually active with females in estrous, which may translate to higher reproductive success for adolescent males. The primary difference between adolescent and adult males seems to be access to dominant females. High-ranking males have a tendency to relate and mate with the same female over a period of several days while younger males might mate with several females in a short amount of time.

Bonnet macaque females do not have sexual swellings, unlike other macaque females. The absence of such swellings in this species may be linked to male cohesion. (Campbell, et al., 2007; Lindberg, 1980; Silk, 1994; Sugiyama, 1971)

Bonnet macaque populations reproduce annually in discrete mating seasons. Most sources agree that the mating season peaks around September to October to produce a birthing season around February and April. Sexual activity is observed throughout the year and seasonality varies greatly by source and population. However, few matings occur during the dry season, late February through early April.

For macaques rate of growth and sexual maturation depends upon feeding and social conditions. In general females reach sexual maturity around 3 years old, typically giving birth to their first offspring at age 4. Male puberty begins at age 3 with full testicular enlargement at age 4 to 5. Gestation averages 24 weeks and the female gives birth to one infant. Infants nurse their mothers until 6 to 7 months old. The average time between births is 1 to 2 years. Female reproductive lifespan produces on average 5 offspring before they undergo menopause around 27 years old. (Campbell, et al., 2007; RAO, et al., 1998; Silk, 1994)

  • Breeding interval
    Bonnet macaques breed once anually.
  • Breeding season
    Breeding season varies regionally, but peaks from September to October.
  • Average number of offspring
    1
  • Average gestation period
    168 days
  • Range weaning age
    6 to 7 months
  • Range time to independence
    9 to 12 months
  • Range age at sexual or reproductive maturity (female)
    32 to 40 months
  • Range age at sexual or reproductive maturity (male)
    2.5 to 5 years

Infants are kept close to their mother for the first six months to a year of life. They ride on her back or are carried in her arms. The mother provides nourishment by nursing for the first 6 to 7 months. After an infant is weaned it remains close to its mother, as it is still somewhat dependent upon its mother for access to food. By one year old young bonnet macaques are able to fend for themselves.

The mother also provides the majority of protection during this time. She usually keeps the infant safe in her arms and is very protective. If an alarm is sounded when the mother-infant pair is apart, the mother will often put herself in harms way to grab the infant and escape. The whole community contributes to the protection of young. Sometimes young adult males will go by themselves or with several mothers to recover isolated infants.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • male
      • female
  • post-independence association with parents

Lifespan/Longevity

Captive lifespan in bonnet macaques is up to 35 years. However, few individuals in wild populations make it to this advanced age. Most females in wild populations do not reach the age of menopause, around 27 years old. Lifespan is usually cut short due to predation, car collisions, or disease. (RAO, et al., 1998)

  • Range lifespan
    Status: captivity
    35 (high) years
  • Typical lifespan
    Status: wild
    20 to 25 years
  • Typical lifespan
    Status: captivity
    25 to 30 years

Behavior

Bonnet macaques are arboreal and terrestrial quadrupeds, although they spend much of their time on the ground. They are typically active during the day. Bonnet macaques use lateral-sequence footfall patterns which allows three or more limbs to remain in contact with a branch and reduces lateral swaying. Juvenile bonnet macaques use their 50 to 70 cm prehensile tail as an anchor when going down steeply inclined branches or for grasping support.

Bonnet macaques live in multimale-multifemale troops averaging 30 individuals. Females are philopatric (remain in natal group) and form kin-bonded subgroups. Males transfer to other troops without a period of solitary life. Female dispersal has also been documented, but seems to be rare. There is a linear ranking order among males and females.

Social grooming is a common behavior in bonnet macaques. Unlike many other primate species, grooming is not a one-way social behavior performed by subordinate individuals on dominant individuals. In bonnet macaques dominant males often spend more time grooming others than do juvenile males. All community members participate in social grooming, which is believed to calm tensions and increase bonding.

During rest or sleep, groups of same-sex bonnet macaques huddle together. Dominant males will clasp juvenile males close to them while adult female mothers will huddle together and leave juveniles, single adult females, and babies to huddle together.

Wrestling and mock attacks are commonly observed in juvenile bonnet macaques. Bonnet macaques are unique in that adult males of all ages regularly join in play. Juveniles and infants repeatedly leap at, kick, cling to, and bite big males, without fear of retribution.

Male-male mounting is a common social behavior, the majority of mounting is a dominant male mounting a juvenile. But one third of all observed male-male mounting was a juvenile male mounting a dominant male. (Campbell, et al., 2007; Johnson, et al., 2007; Lindberg, 1980; Silk, 1994; Sugiyama, 1971)

  • Range territory size
    40 ha to 520 ha cm^2

Home Range

Bonnet macaque troops maintain a home range which varies in size, averaging 50 ha for the core area. Daily use patterns are dependent on food distribution and the distribution of predators. They may stay in the same general area for several months before exploring a new area. Langur species, lion-tailed macaques, and other bonnet macaque troops have overlapping home ranges and mix without aggression. (Sugiyama, 1971)

Communication and Perception

Bonnet macaques use their sensitive hands to gather tactile information on their environment and to participate in grooming. Like many other primates, they have keen vision and can see in color. Vision is relied on heavily to find food, navigate the landscape, and communicate to conspecifics. They have slightly reduced olfaction with narrow, downward facing nostrils. Bonnet macaques use taste to distinguish when fruit is ripe. Alarm calls are an important form of communication. This is a loud vocalization that is emitted in response to detection of a predator.

"Grinning and clicking" is used to express affection and relieve tension. It is characterized by a wide grin with repeated clicking of the tongue. Dominant and subordinate individuals use this form of communication.

"Embracing" occurs when two large males meet. They embrace each other, grip each other’s genitals, and display grinning and clicking behavior. Social tension may be relieved in this greeting behavior.

Females do not advertise sexual receptivity, as they have no sexual swellings. Older, dominant males consort and mate with the same female for several days. Younger males spend less time consorting and mate with several females over the same time span.

Social rank is communicated mostly through maturity, which can be difficult to observe. Some studies have resorted to inducing intra-group aggression through artificial feeding to determine dominance relationships. Results demonstrate that dominance is linear in both males and females. (Ramakrishnan and Coss, 2000; Sugiyama, 1971)

Food Habits

Bonnet macaque populations often rely on food generated by living near human populations. They often inhabit temples where tourists feed them or they take food offerings left at the feet of religious figures. They also raid nearby houses, tourist buses, food stalls, backyard gardens, and large trash piles for food. Populations that do not live near human settlements eat fruits, foliage, insects, and occasional bird eggs or lizards. One account found that a population mainly ate berries, flowers, and young leaves of Lantana, which blooms year-round. Though fruit and young leaves of pongam, fig, karwanda, acacia, tamarind, and nihm were main food items as well. Their favorite food was reported to be grasshoppers (Sugiyama, 1971). Johnson, Hill and Cooper (2007) found that 9 categories made up their diet: vegetation, fruit, human food, soil, seeds, wood, insect, non-food items, and unidentified items. Temple macaque populations ate more vegetation, human food, soil, wood, non-food and unknown items. Forest populations ate more fruit, insects and seeds. (Johnson, et al., 2007; Sugiyama, 1971)

  • Animal Foods
  • reptiles
  • eggs
  • insects
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • nectar
  • flowers

Predation

Bonnet macaques emit high-pitched alarm calls when predators are sighted. They live in groups, which increases the level of vigilance for predators. The alarm call is produced by all members of the group and sounds like “kern kern”. Once an alarm is sounded the community rushes to the shelter of the tree canopy or a bush. In general, the dominant male is the first to come down. Other members paired in twos or threes follow him. Additional data suggests that bonnet macaques are able to recognize and respond to alarm calls of other primate species in the area. They seem to learn the alarm calls of Nilgiri langurs (also called hooded leaf monkeys, Trachypithecus johnii), Hanuman langurs (Semnopithecus entellus), and lion-tailed macaques (Macaca silena) if they are exposed to them frequently enough. Juveniles begin to respond to these alarm calls and the ability to detect them seems to improve with age and experience. Bonnet macaques respond most strongly to alarm calls from their own troop. (Ramakrishnan and Coss, 2000; Sugiyama, 1971)

Bonnet macaques are preyed on by leopards, tigers, eagles, crocodiles, dholes, feral dogs, and large snakes. They are also killed by humans. (Ramakrishnan and Coss, 2000)

Ecosystem Roles

Bonnet macaques often live sympatrically with Nilgiri langurs (Tachypithecus johnii) and Hanuman langurs (Semnopithecus entellus). There is limited competition between these species because of dietary differences. Langurs eat more leaves while bonnet macaques are more omnivorous. Populations that live in forests may help in the dispersal of trees through their frugivory. (Ramakrishnan and Coss, 2000; Sugiyama, 1971)

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Villagers will often sell fruit or rice to tourists specifically to feed macaques at tourist attractions.

Economic Importance for Humans: Negative

Bonnet macaques and other macaque species are sometimes considered pests where they live near human. They can be aggressive and destructive in their efforts to steal food. They also raid crops. (Dewar, et al., 1989; Sugiyama, 1971)

  • Negative Impacts
  • crop pest
  • household pest

Conservation Status

The IUCN Red List of Threatened Species lists bonnet macaques as lower risk/least concern.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Monica Brown (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon.

Glossary

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Campbell, C., A. Fuentes, K. Mackinnon, M. Panger, S. Bearder. 2007. Primates In Perspective. New York Oxford: Oxford University Press.

Coss, R., B. McCowan B, U. Ramakrishnan. 2007. Threat-related acoustical differences in alarm calls by wild bonnet macaques (Macaca radiata) elicted by python and leopard models. Ethology, 113 (4): 352-367.

Dewar, R., S. Goldstein, A. Richard. 1989. Weed macaques: The evolutionary implications of macaque feeding ecology. International Journal of Primatology, 10/6: 569-594. Accessed November 07, 2007 at http://www.springerlink.com/content/93w53180703k3703.

Dunbar, D., G. Badam. 2000. Locomotion and Posture During Terminal Branch Feeding. Internation Journal of Primatology, Volume 21, Number 4: 649-669. Accessed October 07, 2007 at http://www.springerlink.com/content/n7x8x502j2950120/.

Eudey, A., Members of the Primate Specialist Group 2000. 2007. "Macaca radiata" (On-line). 2007 The IUCN Red List of Threatened Species. Accessed November 08, 2007 at www.iucnredlist.org.

Fleagle, J. 1999. Primate Adaptation and Evolution 2nd edition. San Diego, California: Academic Press; An imprint f Elsevier.

Johnson, E., E. Hill, M. Cooper. 2007. Vomiting in Wild Bonnet Macaques. International Journal of Primatology, Volume 28, Number 1: 245-256. Accessed November 06, 2007 at http://0-www.springerlink.com.janus.uoregon.edu/content/7u883073.

Lindberg, D. 1980. The Macaques; Studies in Ecology, Behavior and Evolution. New York, NY: Van Nostrand Reinhold Company.

RAO, A., V. RAMESH, S. RAMACHANDRA, H. KRISHNAMURTHY. 1998. Growth and Reproductive Parameters of Bonnet Monkey (Macaca radiata). PRIMATES, 39(1 ): 97-107. Accessed November 29, 2007 at http://www.springerlink.com/content/a57531lqjl123t0w/fulltext.pdf.

Ramakrishnan, U., R. Coss. 2000. Recognition of Heterospecific Alarm Volcalizations by Bonnet Macaques (Macaca radiata). Journal of Comparative Psychology, Vol. 114, No 1: 3-12.

Ramakrishnan, U., R. Coss. 2001. Strategies Used by Bonnet Macaques (Macaca radiata) to Reduce Predation Risk While Sleeping. Primates, 42(3):: 193--206.

Silk, J. 1994. Social Relationships of Male Bonnet Macaques: Male Bonding in a Matrilineal Society. Behaviour, 130: 272-301.

Singh, M., H. Kumara, M. Kumar, M. Singh, M. Coper. 2006. Male Influx, Infanticide, and Female Transfer in Macaca radiata radiata. International Journal of Primatolgy, Volume 27, Number 2: 515-528. Accessed November 06, 2007 at http://www.springerlink.com/content/x5428k08081r08q0/.

Sugiyama, Y. 1971. Characteristics of the Social Life of Bonnet Macaques (Macaca radiata). Primates, Vol 12 / 3-4: 247-266.