Toque macaque

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Toque macaque[1]
Macaca sinica - 01.jpg
Macaca sinica sinica
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Cercopithecidae
Genus: Macaca
Species: M. sinica
Binomial name
Macaca sinica
(Linnaeus, 1771)
Toque Macaque area.png
Toque macaque range

The toque macaque (Macaca sinica) is a reddish-brown-coloured Old World monkey endemic to Sri Lanka, where it is locally known as the rilewa or rilawa (Sinhala රිළවා), (hence "rillow" in the Oxford English Dictionary). It is named for the toque-shaped whorl of hair on its head, rather like the bonnet of the related bonnet macaque. Toque macaque is the most studied primate in Sri Lanka.

Description[edit]

It lives in troops, sometimes numbering up to 20, and has developed into three subspecies. This is a medium-sized monkey, although it is the smallest living species of macaque. It has a head and body length of 35–62 cm (14–24 in), a tail length of 40–60 cm (16–24 in). Males, at a weight of 4.1 to 8.4 kg (9.0 to 18.5 lb), can occasionally attain much larger sizes than females, at a weight of 2.3 to 4.5 kg (5.1 to 9.9 lb).[3][4][5]

Those living in cold climates have thick, dark brown fur and short limbs and tails, while those living in the lowland rainforest have reddish or golden colored coats and long umbrella-like bonnets. The dry zone race has light coats, long limbs and short bonnets or toque hair. With the age, female gets more pinky face, prominent in the subsp. sinica.

Distribution[edit]

Toque macaques live only in Sri Lanka. Troops of the toque macaque are a common sight in the Cultural Triangle, where many ancient temples are situated, hence earning them the nickname "temple monkey".

Grooming behaviour

They look very different depending on their habitat. Toque macaques prefer natural forest land ranging from sea-level up to 6,000 feet.

M. s. sinica is found from the Vavuniya, Mannar, towards the lowlands of Anuradhapura, Polonnaruwa, Puttalam, and Kurunegala along the arid zone of Monaragala, and Hambantota districts. They avoid central hills and Jaffna peninsula.

M. s. aurifrons can be found sympatrically with subsp. sinica within intermediate regions of the country, such as Kegalle, parts of Kurunegala. They are also found in south-western parts of the island including Galle, and Matara districts with near to Kalu Ganga.

M. s. opisthomelas is recently identified as a separate subspecies, can be found entirely within south-western region of central hill bordered with Ratnapura, and Nuwara Eliya districts. They can be seen around the Hakgala Botanical Garden and other cold climatic montane forest patches.[6]

Taxonomy[edit]

The three recognized subspecies of toque macaques are:

  • Dryzone toque macaque or Common toque macaque = Macaca sinica sinica
  • Wetzone toque macaque or Pale-fronted toque macaque = Macaca sinica aurifrons
  • Highland toque macaque or Hill-zone toque macaque = Macaca sinica opisthomelas

M. s. sinica is more reddish brown than other two subspecies. The wet zone M. s. aurifrons has a browner hue dorsally back yellow. M. s. opisthomelas is similar to subsp. aurifrons, but has long fur and contrasting golden color in the anterior part of its brown cap.

The three subspecies can identified through the orientation of their different hair patterns.

Social structure[edit]

The social status is highly structured in toque macaques, where they prevail dominance hierarchies among both males and females. Females change the number of individual composition within a troop. A troop may consist very few as 8 to large as 40. When the troop becomes too much, social tension and aggression towards each other arise, which giving some individuals to flee from the troop. This is remarkable in adults and sub adults, where a troop may consist largely with females. Newly appointed alpha male also show aggressiveness towards females, which results flee. There are sightings, where there are severe fights between individuals of the same troop and some gets heavy wounds to cheeks, eyes, and sometimes carry broken arms.[6]

The social unit in toque macaques was not identical to the reproductive unit and the possibility of paternity by males outside the social group should be considered when estimating male reproductive output. Although it was common for multiple males to father offspring in a social group each year, reproduction within a group during a breeding season tended to be limited to a few males. The mean number of males reproducing per group per year was independent of the number of males in a group. The paternity data suggests that many males may father relatively few offspring during their entire lives.[7]

Reproduction[edit]

When in estrous, the female's perineum becomes reddish in color and swells. This change is a signal to the males that she is ready to mate. There is an average of 18 month between births. After a 5–6 month gestation period, female macaque give birth to a single offspring. Offspring hold on to their mothers for about 2 months. During this time they learn survival techniques and social skills critical for survival. The infants are born into their social classes based on their mothers position in the troop. Young males are forced to abandon their troop when they are about 6–8 years of age. This prevents in-breeding and ensures that the current alpha male maintains his position in the troop. Leaving the troop is the only way a male can change his social standing. If he has good social skills and is strong he may become an alpha male. A single alpha male can father all of the troops' offspring.[6]

Macaca sinica opisthomelas

Most toque macaques give birth to their infants during the night when resting arboreally. Birth rarely occurs during the day or on the ground. Prepartum behaviors include: arching of the back, stretching, squatting, rolling on the ground, and anogenital self-examination. During labor the female isolates herself from the group (about 100 m). The mother stands bipedally during parturition and assists the delivery with her hands. The infant is usually born 2 minutes after crowning. The infant can vocalize almost immediately after birth; it is important for the mother and infant to recognize each other's voices. Vocalization will be used to alert the mother of imminent danger, and can assist in finding each other if separated. After birth the mother licks the infant and orients it toward her breasts. She will resume foraging behavior within 20 minutes after parturition. The mother also eats part of the placenta, because it is contains needed protein. The alpha female of the group asserts her power by taking part of the placenta for herself to eat.[8]

Diet[edit]

Toque macaques are mainly frugivorous, and are likely to eat fruit, seeds, nuts, mushrooms, tubers, invertebrates and occasionally animals, including reptiles and birds. They are fond of eating drooping yellow clusters of flowers of Cassia fistula. All are expert raiders of crops where humans encroach on their habitat. They eat any good thing making use of human detritus by going after plantains, pineapples, rice grains, papaws, and mangoes. Even there are plenty of foods present in natural habitation, toque macaques enjoy to take any food with little effort around human dwellings. They are occasionally seen around houses near a forest patch, where they invade all the fruiting plants in the day sessions and return back to the forest cover in night. Because, these macaques have very little fear for humans and their companions-the dogs.

Cheek pouches enable toque macaques to store enough food while eating fast. In the dry zone, they are known to eat drupes of understory shrub Zizyphus, ripe fruits of Ficus, and Cordia species. They occasionally eat many small animals ranging from small insects to mammals like indian palm squirrels and Vandeleuria oleracea.[6]

Predators[edit]

Wild cats (leopards and fishing cats) and Indian rock python are the main predators of this species. The toque macaque is endangered; their rainforest home is being cut down for logging and for farming.

In the wild, this species has an average life span of less than 5 years. Little is known about its longevity in captivity, but one animal lived 29.3 years.[9]

Communication[edit]

Vocal[edit]

  • scream calls: This call is given by the toque macaque when they are approached by a non-group conspecific.
  • loud call: This is emitted by the male, and is used to maintain intergroup spacing. A group will move away upon hearing this call.[10]

Visual[edit]

  • fear grimace: The lips are retracted so that the teeth are shown; the teeth are clenched together. This display functions as an appeasement signal to reduce aggression in aggressive encounters.
  • staring with open mouth: This is the stare accompanied by the mouth being open but the teeth are covered. This is a threat expression.

Conservation[edit]

IUCN listed toque macaque as Endangered in their list due to habitat destruction and hunting, and also for taming for pets. all the three subspecies are recognized as endangered entirely in their natural habitats. With few patches of forests for survival, they engage to survive close to human habitation, giving a serious trouble for both the parties. Due to devastated eating of crop plants, humans always take precautions to avoid their entrance to the cultivation fields. This results killing by shot, trappings, and poisoning.

Both subsp. aurifrons and sinica are kept as pets by various indigenous people for economic purposes. They were heavily used by both Sri Lanka Army and LTTE for their shooting practices in the recent past, but now prohibited.[2]

Antibody prevalence[edit]

In an experiment, serum samples taken from toque macaque individuals at Polonnaruwa were examined for antibodies to Toxoplasma gondii by the modified agglutination test. There was no evidence of maternal transmission of antibodies or congenital toxoplasmosis. None of the infected macaques died within 1 year after sampling. Toxoplasma gondii infection was closely linked to human environments where domestic cats were common. Although infection with T. gondii has been noted in several species of Asian primates, this is the first report of T. gondii antibodies in toque macaques.

As dengue reservoir[edit]

It is unclear if nonhuman primates also serve as a reservoir of human dengue viruses under certain conditions. According to a study by some biologists, a cross-sectional serologic survey was carried out to characterize the pattern of transmission of a recently identified dengue virus among toque macaques in Sri Lanka. The results indicated that an epizootic dengue virus was active among the macaques. A single epizootic had taken place between October 1986 and February 1987 during which 94% of the macaques within the 3 km2 study site were exposed to the virus. The epizootic was highly focal in nature because macaques living 5 km from the study population were not exposed to the virus. The transmission of dengue viruses among macaques in the wild may have important public health implications.[11]

In popular culture[edit]

A group of toque macaques who were chased from their home by a rival group searching for a new home in the historic city of Polonnaruwa is shown in the Disney movie Monkey Kingdom.

References[edit]

  1. ^ Groves, C.P. (2005). Wilson, D.E.; Reeder, D.M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. p. 164. OCLC 62265494. ISBN 0-801-88221-4. 
  2. ^ a b Dittus, W., Watson, A. & Molur, S. (2008). Macaca sinica. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 4 January 2009.
  3. ^ [1]
  4. ^ [2]
  5. ^ Novak, R. M. 1999. Walker's Mammals of the World. 6th edition. Johns Hopkins University Press, Baltimore. ISBN 0-8018-5789-9
  6. ^ a b c d Yapa, A.; Ratnavira, G. (2013). Mammals of Sri Lanka. Colombo: Field Ornithology Group of Sri Lanka. p. 1012. ISBN 978-955-8576-32-8. 
  7. ^ http://www.ncbi.nlm.nih.gov/pubmed/9076981
  8. ^ http://link.springer.com/article/10.1007%2FBF02735202#page-1
  9. ^ http://genomics.senescence.info/species/entry.php?species=Macaca_sinica
  10. ^ http://www.theprimata.com/macaca_sinica.html
  11. ^ http://www.ajtmh.org/content/60/2/300.full.pdf

External links[edit]