Semnopithecus entellusHanuman langur

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Geographic Range

The geographic range of Semnopithecus entellus (Hanuman langur) spans from Kashmir in north India and the Himalayas in Nepal, Bhutan, and Tibet south to Sri Lanka, east to Bangladesh and west to the Indus valley in Pakistan (Gron, 2008). It is thought that a single breeding pair resulted in the population found in southeast Bangladesh. (Gron, 2008; Mitra and Molur, 2008)

Habitat

Hanuman langurs are found in a wide variety of habitats, ranging from arid to tropical evergreen rainforests. They are also known to live in close proximity to humans, including the city of Jodhpur, India, which has over a million inhabitants (Gron, 2008). They are forest dwelling primates in India but are found only in forest openings in Bangladesh (Farid Ahsan and Reza Khan, 2006). The amount of rainfall varies greatly throughout their range (10 to 200 cm). Hanuman langurs are able to withstand a wide range of temperatures, from -7˚C to 46˚C, and spend about 80% of their time on the ground. (Carlson, 2004; Farid Ahsan and Reza Khan, 2006; Gron, 2008)

Physical Description

Hanuman langurs have brownish gray fur, with a tinge of red on their dorsal surface and white fur on their ventral surface. Their feet, hands, face, and ears are black, and their face is framed with white fur. Their tail is usually longer than the body, with a white tip. Infants are born with fine, dark brown or black fur. Their skin is pale, but darkens to black by three months old. They are sexually dimorphic, with males being slightly larger than females. Males weigh about 13 kg and females weigh about 9.9 kg. Excluding their tail, males are about 64 cm long, and females are about 58.5 cm long. Male Hanuman langur tails average 91.0 cm and those of females average 86 cm. They have 32 teeth and their dental formula is 2/2 1/1 2/2 3/3. ("Old World monkeys I", 2004; Gron, 2008)

  • Sexual Dimorphism
  • male larger
  • Range mass
    9.9 to 13 kg
    21.81 to 28.63 lb
  • Range length
    58.5 to 64 cm
    23.03 to 25.20 in

Reproduction

Hanuman langurs live in both polygynous and polygynandrous groups, and unpaired males form bachelor groups. Male dominance is usually determined through fighting, whereas younger, sexually mature females are higher ranking, and decrease in rank with age. Females advertise estrous via head shaking and presenting the anogenital region to potential mates. Females continue mating during gestation to prevent infanticide by dominant males. ("Old World monkeys I", 2004; Gron, 2008)

Females typically reach sexual maturity by 2.9 years of age, with males reaching sexual maturity by 5 years of age. Hanuman langurs breed between July and October, and parturition occurs between February and April. Gestation lasts for 200 to 212 days, after which a single infant is usually born. Although rare, females may also give birth to twins. ("Old World monkeys I", 2004; Gron, 2008)

  • Breeding interval
    Hanuman langurs breed once annually.
  • Breeding season
    Varies by locations, but often falls between July to October.
  • Range number of offspring
    1 to 2
  • Range gestation period
    200 to 212 days
  • Range weaning age
    8.6 to 13 months
  • Range time to independence
    1 to 2 years
  • Average age at sexual or reproductive maturity (female)
    2.9 years
  • Average age at sexual or reproductive maturity (male)
    5 years

Infant Hanuman langurs spend the first week of life with their mothers. After that, infants are also cared for by other females that have recently given birth to young; however, the mother still provides most of the care. By six weeks old, infants begin eating on their own. Weaning doesn’t begin until 8 months old and is complete by 13 months old. Between the ages of 9 to 12 months, infants are only around their mother 20% of the time. Males are forced to disperse before they become sexually mature, while females stay with their natal group. Hanuman langurs are independent by 2 years old. ("Entellus [=Sacred] Langur", 1998; Carlson, 2004; Gron, 2008)

Mothers are very protective of their infants, which often remain at the center of the group for increased protection. Females from surrounding groups sometimes kidnap infants, however, mothers often risk their lives to retrieve their offspring. ("Entellus [=Sacred] Langur", 1998; Carlson, 2004; Gron, 2008)

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

Lifespan/Longevity

In captivity Hanuman langurs often live into their early thirties. In the wild, males can live to 18 years old, and females can live to 30 years old. (Gron, 2008)

  • Typical lifespan
    Status: wild
    18 to 30 years
  • Typical lifespan
    Status: captivity
    >30 (high) years

Behavior

Hanuman langurs are diurnal and semi-arboreal, spending 80% of their time on the ground using quadrupedal locomotion. They use trees primarily for sleeping. Dominance hierarchies play an important role in tree use behavior. The highest ranking male sleeps at the highest position in the tree, because it is the safest. Directly below the dominant male are females and their offspring, then younger females, with adolescent males at the lowest position. Hanuman langurs are gregarious and form groups ranging from 2 to over 100 members. They can be both polygynous and polygynandrous and sometimes form bachelor groups. During summer they are more active in the morning and evening, whereas in the winter they are more active during midday. (Carlson, 2004; Gron, 2008)

  • Range territory size
    0.07 to 22 km^2

Home Range

Hanuman langurs can have home ranges from 0.07 to 22 km^2. Bachelor groups typically have larger home ranges than other groups. They usually do not move their home ranges. (Gron, 2008)

Communication and Perception

Hanuman langurs have about 19 different types of calls. In the morning, mature males make a loud whooping call when leaving their sleeping trees. They may also make cacophonous barks if they are surprised by a predator. Adult and sub-adult males often grunt or cough during group movements. Isolation peeps can be heard from members who get lost or separated from their group. They often groom each other, which is performed according to local dominance hierarchies. Dominant Hanuman langurs groom one another and receive grooming more often than subordinate langurs. They use their vision to find food and move around their environment and females display estrous via head shaking. (Gron, 2008)

Food Habits

Hanuman langurs are primarily herbivores. Their diet is composed of leaves (52-61%), fruits (15-25%), flowers (4-13%), insects (0.4-3%), and other foods such as bark, gum, and soil (9-16%) (Gron, 2008). More developed leaves are preferred over young leaves. They are not highly selective foragers, and consume human food when available. In times of food shortage, they are known to consume bark. (Gron, 2008)

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

Predation

Hanuman langurs are preyed upon by leopards (Panthera pardus), dholes (Cuon alpinus), tigers (Panthera tigris), wolves (Canis lupus), and golden jackals (Canis aureus). They sleep in the upper forest canopy to avoid predators while resting; however, deforestation has reduced the number of roosting trees, giving predators easier access to langurs, potentially increasing predator induced mortality (Gron, 2008). (Gron, 2008)

Ecosystem Roles

Hanuman langurs live sympatrically with Bonnet macaques (Macaca radiata), toque macaque (Macaca sinica), and hooded leaf monkeys (Trachypithecus johnii). Each species occupies a distinct niche, therefore, they are able to live with one another with little to no resource competition. Soapberry bug nymphs (Leptocoris augur) rely on Hanuman langurs to remove fruit casings, enabling them to eat. (Gron, 2008)

  • Ecosystem Impact
  • disperses seeds
Commensal/Parasitic Species
  • Soapberry bug (Leptocoris augur)

Economic Importance for Humans: Positive

Hanuman langurs are sacred animals in many parts of India. Various body parts are sometimes kept as amulets, which are thought to have a positive effect on the bearer (Gron, 2008). (Gron, 2008)

  • Positive Impacts
  • pet trade
  • body parts are source of valuable material

Economic Importance for Humans: Negative

Hanuman langurs are known to raid crops and steal food from people’s homes. (Gron, 2008)

  • Negative Impacts
  • crop pest

Conservation Status

Hanuman langurs are listed as a species of "least concern" on the IUCN Red List of Threatened Species. It was previously listed as near threatened in 2004. (Mitra and Molur, 2008)

Other Comments

S. entellus was previously known as Presbytis entellus. They received their common name, Hanuman langur, from Hanuman who is the monkey-god. ("Old World monkeys I", 2004; Gron, 2008)

Contributors

Rebecca Semke (author), University of Wisconsin-Stevens Point, Stefanie Stainton (editor), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, John Berini (editor), Animal Diversity Web Staff.

Glossary

acoustic

uses sound to communicate

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.

arboreal

Referring to an animal that lives in trees; tree-climbing.

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.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

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

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

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.

oriental

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

World Map

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynandrous

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

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

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

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

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

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

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

1998. Entellus [=Sacred] Langur. Pp. 99 to 101 in W Beacham, K Beetz, eds. Beacham's Guide to International Endangered Species, Vol. 1, First Edition. Osprey, Florida: Beacham Publishing Corp..

2004. Old World monkeys I. Pp. 10, 173, 175, 176, 180 in M Hutchins, D Kleiman, V Geist, eds. Grzimek's Animal Life Encyclopedia, Vol. 14, Second Edition. Farmington Hills, MI: Gale Group.

Borries, C. 1997. Infanticide in seasonally breeding multimale groups of Hanuman langurs (Presbytis entellus) in Ramnagar (South Nepal). Behavioral Ecology and Sociobiology, 41: 139-150.

Borries, C., A. Koenig, P. Winkler. 2001. Variation of life history traits and mating patterns in female langur monkeys (Semnopithecus entellus). Behavioral Ecology and Sociobiology, 50/5: 391-402.

Carlson, J. 2004. "Hanuman Langur Semnopithecus entellus" (On-line). Accessed July 29, 2010 at http://www.bio.davidson.edu/people/vecase/behavior/Spring2004/carlson/carlson.html.

Farid Ahsan, M., M. Reza Khan. 2006. "Eco-ethology of the common langur Semnopithecus entellus (Dufresne) in" (On-line). Accessed July 29, 2010 at http://www.banglajol.info/index.php/UJZRU/article/viewFile/317/371.

Gron, K. 2008. "Gray langur Semnopithecus" (On-line). Accessed July 28, 2010 at http://pin.primate.wisc.edu/factsheets/entry/gray_langur.

Mitra, S., S. Molur. 2008. "Semnopithecus entellus" (On-line). Accessed July 28, 2010 at http://www.iucnredlist.org/apps/redlist/details/39832/0.