Phayre's leaf monkey

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Phayre's leaf monkey
laauy'aachdd'aar jiibn citr - cshmaapraa hnumaan 02.jpg
In Lawachara National Park
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Cercopithecidae
Genus: Trachypithecus
Species:
T. phayrei
Binomial name
Trachypithecus phayrei
(Blyth, 1847) [2]
Trachypithecus crepusculus T phayrei area.png
Phayre's leaf monkey range in green (includes T. melamera )

Phayre's leaf monkey (Trachypithecus phayrei), also known as Phayre's langur, is a species of Old World monkey native to South Asia and Southeast Asia, namely India, Bangladesh, and Myanmar. Populations from further east are now thought to belong to other species. It is listed as Endangered on the IUCN Red List and is threatened by hunting and loss of habitat. [1] The species epithet commemorates Arthur Purves Phayre.

Contents

Taxonomy

The scientific name Presbytis phayrei was used by Edward Blyth in 1847 for two young individuals captured alive in the Arakan Mountains in Myanmar. [3] Phayre's langur is one of the most widespread members of the genus, but its actual distribution and intraspecific taxonomy remain controversial. Previously, three subspecies were recognized, namely T. p. crepusculus, T. p. phayrei and T. p. shanicus. [2]

Three separate species T. phayrei, T. melamera (formerly T. p. shanicus), and T. popa sp. nov. have been proposed based on mitochondrial genomes. Currently, the name Phayre's leaf monkey refers to T. phayrei, residing in forests of East Bengal, Northeast India and western Myanmar, specifically, areas to the west of the Chindwin and Irrawaddy Rivers. [4]

Characteristics

Phayre's langur is characterized by white coloration around the ventral, mouth, and eye area. The broad ring-shaped patches around the eyes resemble spectacles, contributing to the local name of “Chasma bandor” in Bengali, or spectacled monkey. The white fur is especially contrasting with the overall deep bluish-brown fur all over its body with darker shades at the head, below the elbows, and at the end of the tail. [5] There is a presence of a sagittal crest on the heads of both adult males and females, giving it a triangular shape. The infants have a straw-colored natal coat, making it easily distinguishable in a group. [6] The average head-body length ranges from 530–580 mm (21–23 in) in males and 495–580 mm (19.5–22.8 in) in females. The tail is usually longer than its body, with an average of 700 mm (28 in) for males and 750 mm (30 in), for females. In comparison to T. melamera and T. popa, it has a shorter tail length. [4] The average mass of Phayre's langur is observed to be around 7.9 kg (17 lb) for males and 6.9 kg (15 lb) for females. [7]

In field studies males and females are differentiated through the shape of the patches around the eyes. Female have cone-shaped white patches bending in towards the nose while males have a rounder shape. This shape difference causes a slightly wider gap in males than in females. [8]

Like most Old World monkeys, it has the dental formula of 2.1.2.32.1.2.3 [9] Distinctive to other colobines Phayre's langur show craniodental adaptations such as medially positioned rows of teeth and stronger masseter pterygoid muscles for seed-eating. [10]

Distribution and habitat

The Phayre's leaf Monkey resting in bamboo plants in Lawachara National Park cshmaa praa baaNdr.jpg
The Phayre's leaf Monkey resting in bamboo plants in Lawachara National Park

Pharye's langur is found in tropical, deciduous, and evergreen forests of North-East India, Eastern Bangladesh, and Western Myanmar. It can also be seen residing in secondary forests such as bamboo clusters and rubber plantations. Tree species with large canopies like Artocarpus chama , Artocarpus lacucha , Ficus racemosa , Trophis aspera, Mangifera indica , and Grewia nervosa, in Bangladesh, are used for resting in their shade. [11] In India, the most common roosting trees range from heights of 6–15 m (20–49 ft) and have an extensive canopy, e.g., Ficus hispida and Triadica sebifera in Mizoram. [7] Currently, a total of 1200 individual langurs have been recorded in India and 376 individuals in Bangladesh, [1] 288 of which resided in the northeastern forests of Bangladesh. [12]

Behavior and ecology

Group structure

The Phayre's langur usually forms multi-male and multi-female with a presence of a dominant male alpha in the group. All-male groups, one-male groups, and one-female groups have also been observed though, less common. A high level of territoriality is seen within the species and between groups. [7] [13] The groups tend to maintain occupancy in their home range, showing philopatry. [7] Foraging is done by maintaining groups throughout different ranges. While foraging, groups tend to avoid ranging areas of neighboring groups suggesting the formation of borders between them, agonistic interactions are observed in places of overlapping borders. [7] [14]

Female dispersal is also observed between the groups, females that leave the group tend to obtain alpha rank in the new group. Linear dominance is seen in females, where rank has a linear relationship with age. [15] [16] Males on reaching maturation show some dispersal, they either form new multi-male groups or return to their natal group. For males, age and rank dominance also show a linear relationship though, the ranks can change depending on the resource-holding potential, which is shown to decrease in aging monkeys. [13]

Reproduction

Female Phayre's langurs are pregnant by an average age of 5.3 years with an average gestation period of 205 days. [17] The females show promiscuous behavior, studies do show a preference for more experienced males, usually of higher dominance. Polygynous relationships are common, where males offer protection to copulated females. [13]

Females usually nurse their infants on average 22 months with weaning at around 19–21 months. The natal coat starts to become darker 26 weeks after birth. [18]

Communication

Vocalization is observed in both males and females. Based on observations in the wild, a loud “kah-kah-kah” is used to sound alarm in the troop, while in the presence of a predator a softer “whoo” call is used. [15] The dominant male alpha uses the “cheng-kong” sound to assemble the group. Additionally, vocalization essential is for maintaining contact with troop members while foraging. In agonistic interactions, barking sounds such as “ngre-go, ngre-go” are used to maintain their group's territory. [5] [7]

Activity budget

The Phayre's Leaf Monkey is diurnal and arboreal. The average life span of it being 20–30 years, in the wild, and an average of 28.3 in captivity. [7] A study conducted in the Satchari National Park, Bangladesh, found on average the Phayre's leaf Monkey spends, most of its time foraging and feeding (40.7%), the rest is spent traveling (31.8%), resting (18.3%), grooming (7.8%) and playing (1.4%). [11] It is seen that males and juveniles tend to spend more time moving than adult females, who also have the highest percentage of resting among them. It is noticed that the activity patterns have variations based on habitats, seasons, and food availability, for example, food shortages lead to increased travel time. The variation in caloric content of different foods have shown to affect the energy budgets, i.e., poor quality food leads to higher feeding distribution to maintain the caloric requirements. [7] [11]

Diet

The Phayre's leaf monkey is a folivore. It feeds on leaves, shoots, seeds, flowers, gum, and fleshy parts of fruits. The diet varies between seasons and different regions, showing adaptation to the local flora.

In Dampa Tiger Reserve, the Phayre's langurs feeds on Citrus grandis , Gmelina arborea , Ficus maclellendii , Buetneria pilosa, with a preference towards bamboos such as Musa ornata , Melocanna baccifera and Dendrocalamus longispathus during summer. [19] Plant parts with less fiber and high proteins and sugars such as young leaves are usually preferred while foraging. [7] In Satchari National Park in Bangladesh, they feed primarily on Ficus hispida , Albizia chinensis , and Vachellia nilotica . [11]

The high bamboo consumption in their diets is attributed to the abundance of this plant in North-East India because of its invasive nature. [20] Phayre's langurs living in local rubber plantations in Mizoram majorly consume leaves of Hevea brasiliensis showing that diet is affected by the plant diversity in its home range. [7]

In Tripura, India, it mainly feeds on leaves of Albizia procera , Albizzia lebbek and A. stipulata, Melocanna bambusoides , Macaranga denticulata , Callicarpa arborea , Dillenia pentagyna , Litsea sp., Mikania scandens , Gmelina arborea , Artocarpus chaplasha , Syzygium fruticosum , Ficus racemosa , Ficus hispida , Ficus indica and F. fistulosa. [21]

Conservation

The IUCN Red List has deemed the population of Phayre's langur to be decreasing. The recent reclassification of Phayre's langur has led to the underestimation of the status of the decline in the species' population. It is also listed in the CITES Appendix II, to protect its illegal poaching and trading locally. The major threats to Phayre's langur are habitat destruction, fragmentation, logging, roadkill, ecotourism, electrocution and hunting. [11] [22]

In India, organizations like the Wildlife Trust of India have employed wildlife staff trained in anti-poaching tactics to work in forests, and locals have also been involved. [15] In both India and Bangladesh, Pharye's langur is protected through national and local legislation and through implementation of international conservation laws and policies, i.e., the Wild Life (Protection) Act, 1972, in India and Wildlife (Conservation and Security) Act, 2012, in Bangladesh .

The ‘ jhooming ‘, a form of shifting cultivation practiced by tribes in India, led to concerns over reducing forestland for the Phayre's langur population, but a study showed that they adapted to the local practice. The regenerating secondary forests through ‘jhooming‘ provide a habitat for the langurs when primary forests are unsuitable to stay in due to anthropogenic factors. [23]

Related Research Articles

<i>Semnopithecus</i> Genus of Old World monkeys

Semnopithecus is a genus of Old World monkeys native to the Indian subcontinent, with all species with the exception of two being commonly known as gray langurs. Traditionally only the species Semnopithecus entellus was recognized, but since about 2001 additional species have been recognized. The taxonomy has been in flux, but currently eight species are recognized.

<span class="mw-page-title-main">Purple-faced langur</span> Species of Old World monkey

The purple-faced langur, also known as the purple-faced leaf monkey, is a species of Old World monkey that is endemic to Sri Lanka. The animal is a long-tailed arboreal species, identified by a mostly brown appearance, dark face and a very shy nature. The species was once highly prevalent, found in suburban Colombo and the "wet zone" villages, but rapid urbanization has led to a significant decrease in the population level of the monkeys. It had traditionally been classified within the genus Trachypithecus but was moved to the genus Semnopithecus based on DNA evidence indicating that is it more closely related to the gray langurs.

<span class="mw-page-title-main">Colobinae</span> Subfamily of Old World monkeys

The Colobinae or leaf-eating monkeys are a subfamily of the Old World monkey family that includes 61 species in 11 genera, including the black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications split the colobine monkeys into two tribes, while others split them into three groups. Both classifications put the three African genera Colobus, Piliocolobus, and Procolobus in one group; these genera are distinct in that they have stub thumbs. The various Asian genera are placed into another one or two groups. Analysis of mtDNA confirms the Asian species form two distinct groups, one of langurs and the other of the "odd-nosed" species, but are inconsistent as to the relationships of the gray langurs; some studies suggest that the gray langurs are not closely related to either of these groups, while others place them firmly within the langur group.

<i>Trachypithecus</i> Genus of Old World monkeys

Trachypithecus is a genus of Old World monkeys containing species known as lutungs, langurs, or leaf monkeys. Their range is much of Southeast Asia.

<span class="mw-page-title-main">Gee's golden langur</span> Species of Old World monkey

Gee's golden langur, also known as simply the golden langur, is an Old World monkey found in a small region of Western Assam, India and in the neighboring foothills of the Black Mountains of Bhutan. Long considered sacred by many Himalayan people, the golden langur was first brought to the attention of the Western world by the naturalist Edward Pritchard Gee in the 1950s. Adult males have a cream to golden coat with darker flanks while the females and juveniles are lighter. The golden langur has a black face and a long tail up to 50 cm (19.69 in) in length. It lives in high trees and has a herbivorous diet of fruits, leaves, seeds, buds and flowers. The average group size is eight individuals, with a ratio of several females to each adult male. It is one of the most endangered primate species of India and Bhutan.

<span class="mw-page-title-main">Nilgiri langur</span> Species of Old World monkey

The Nilgiri langur is a langur. This primate has glossy black fur on its body and golden brown fur on its head. It is similar in size and long-tailed like the gray langurs. Females have a white patch of fur on the inner thigh. It typically lives in troops of nine to ten monkeys. Its diet consists of fruits, shoots and leaves. The species is classified as vulnerable due to habitat destruction and poaching for its fur and flesh, the latter believed to have aphrodisiac properties.

<span class="mw-page-title-main">Silvery lutung</span> Species of Old World monkey

The silvery lutung, also known as the silvered leaf monkey or the silvery langur, is an Old World monkey. It is arboreal, living in coastal, mangrove, and riverine forests in Peninsular Malaysia, Sumatra, Borneo, Java, and other nearby islands.

<span class="mw-page-title-main">François' langur</span> Species of Old World monkey

François' langur, also known as Francois' leaf monkey, the Tonkin leaf monkey, or the white side-burned black langur is a species of Old World monkey and the type species of its species group. It is one of the least studied of the species belonging to the Colobinae subfamily.

<span class="mw-page-title-main">Raffles' banded langur</span> Species of primate in Malaysia and Singapore

The Raffles' banded langur, also known as the banded leaf monkey or banded surili, is a species of primate in the family Cercopithecidae. It is endemic to Singapore and southern Peninsular Malaysia. The species underwent taxonomic revisions in 2019 and 2020, in which two former subspecies were elevated to separate species. As a result, the Raffles' banded langur meets the criteria for being listed as critically endangered by the IUCN. It is mainly threatened by habitat loss.

<span class="mw-page-title-main">Mentawai langur</span> Species of Old World monkey

The Mentawai langur is a species of primate in the family Cercopithecidae. It is endemic to the Mentawai Islands in Indonesia. Its natural habitat is subtropical or tropical dry forests. The Siberut langur was formerly considered a subspecies of the Mentawai langur.

<span class="mw-page-title-main">Dusky leaf monkey</span> Species of Old World monkey

The dusky leaf monkey, also known as the spectacled langur or the spectacled leaf monkey, is a species of primate in the family Cercopithecidae. It is found in Peninsular Malaysia, Myanmar and Thailand, and can occasionally be found in Singapore. During the day, these small, folivorous primates divide in sub-groups and forage for vegetation and fruit throughout the tropical forests. According to the IUCN, the dusky leaf monkey's population is declining due to habitat loss, poaching, and anthropogenic land use, which prompted the IUCN to classify the species as endangered in 2015.

<span class="mw-page-title-main">Germain's langur</span> Species of Old World monkey

Germain's langur is an Old World monkey native to Thailand, Myanmar, Cambodia, Laos and Vietnam. The monkey was previously included in Trachypithecus cristatus and Trachypithecus villosus.

<span class="mw-page-title-main">Kashmir gray langur</span> Species of Old World monkey

The Kashmir gray langur is an Old World monkey, one of the langur species. It is a leaf-eating monkey.

<span class="mw-page-title-main">Tufted gray langur</span> Species of Old World monkey

The tufted gray langur, also known as Madras gray langur, and Coromandel sacred langur, is an Old World monkey, one of the species of langurs. This, like other gray langurs, is mainly a leaf-eating monkey. It is found in southeast India and Sri Lanka. It is one of three Semnopithecus species named after characters from The Iliad, S. hector and S. ajax being the others. In Sinhala it is known as හැලි වදුරා.

<span class="mw-page-title-main">Selangor silvered langur</span> Species of Old World monkey

The Selangor silvered langur is a species of leaf monkey found on the west coast of Peninsular Malaysia. It had been previously considered a form of silvery lutung. Roos and colleagues elevated this population to a subspecies level, Trachypithecus cristatus selangorensis, in 2008. It has since come to be regarded by primatologists as a separate species, Trachypithecus selangorensis.

<span class="mw-page-title-main">Miller's langur</span> Species of leaf monkey (mammal)

Miller's langur, also known as Miller's grizzled langur or Kutai grey langur, is a species of leaf monkey. It is endemic to East Kalimantan on the island of Borneo in Indonesia. It is one of the world's most endangered primates, and was at one time thought to be extinct, until it was rediscovered in 2012.

<span class="mw-page-title-main">Popa langur</span> Species of mammal

The Popa langur is a species of primate in the family Cercopithecidae. It occurs only in Myanmar and was named after Mount Popa, where a population of 100 of the monkeys live. It is listed as Critically Endangered on the IUCN Red List, as the wild population is thought to comprise 200 to 250 mature individuals.

The Shan State langur is a subspecies of primate in the family Cercopithecidae. It is found in eastern Myanmar and southwest China. While it is typically considered a subspecies or even a synonym of Phayre's leaf monkey, it is sometimes listed as a full species.

<span class="mw-page-title-main">Indochinese grey langur</span> Species of monkey

The Indochinese grey langur is a species of Old World monkey native to East and Southeast Asia.

<span class="mw-page-title-main">Presbytini</span> Tribe of Old World monkeys

Presbytini is a tribe of Old World monkeys that includes all of the Asian colobine monkeys.

References

  1. 1 2 3 Chetry, D. & Ahmed, T. (2021). "Trachypithecus phayrei". IUCN Red List of Threatened Species . 2021: e.T175862145A175862149. Retrieved 18 November 2021.
  2. 1 2 Groves, C. P. (2005). "Species Trachypithecus (Trachypithecus) phayrei". In 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. 178. ISBN   0-801-88221-4. OCLC   62265494.
  3. ↑ Blyth, E. (1847). "Presbytis phayrei, nobis". Journal of the Asiatic Society of Bengal. 16 (2): 733.
  4. 1 2 Roos, C.; Helgen, K. M.; Miguez, R.P.; Thant, N.M.L.; Lwin, N.; Lin, A.K.; Lin, A.; Yi, K.M.; Soe, P.; Hein, Z.M.; Myint, M.N.N. (2020). "Mitogenomic phylogeny of the Asian colobine genus Trachypithecus with special focus on Trachypithecus phayrei (Blyth, 1847) and description of a new species". Zoological Research. 41 (6): 656–669. doi: 10.24272/j.issn.2095-8137.2020.254 . PMC   7671912 . PMID   33171548.
  5. 1 2 Choudhray, A. (2001). A systematic review of the mammals of North-East India with special reference non-human to primates (PhD Thesis). Gauhati: Gauhati University, India.
  6. ↑ Alley, T.R. (1980). "Infantile colouration as an elicitor of caretaking behaviour in old world primates". Primates. 21 (3): 416–429. doi:10.1007/BF02390470. S2CID   39004541.
  7. 1 2 3 4 5 6 7 8 9 10 Bose, J. (2005). An ecobehavioural study of Phayre's leaf monkey Trachypithecus phayrei (Blyth, 1847) (PhD Thesis). Gauhati: Gauhati University, India.
  8. ↑ Bhattacharya, T.; Chakraborty, D. (1990). "Sex identification of the Phayre's leaf monkey (Presbytis phayrei BLYTH, 1847) with the help of facial marks". Primates. 31 (4): 617–620. doi:10.1007/BF02382547. S2CID   35216292.
  9. ↑ Ankel-Simons, F. (2007). "Teeth". Primate Anatomy (Third ed.). Academic Press. pp. 223–281. doi:10.1016/B978-012372576-9/50009-7. ISBN   9780123725769.
  10. ↑ Koyabu, D. B.; Endo, H. (2010). "Craniodental mechanics and diet in Asian colobines: Morphological evidence of mature seed predation and sclerocarpy". American Journal of Physical Anthropology. 142 (1): 137–148. doi:10.1002/ajpa.21213. PMID   20091848.
  11. 1 2 3 4 5 Naher, H.; Mondal, T.; Hasan, S.; Muzaffar, S.; Khan, S. (2022). "Activity Budget and Diet of Phayre's Langur (Trachypithecus phayrei) in Satchari National Park, Bangladesh". Primate Conservation. 36: 1–17.
  12. ↑ Ahmed, T.; Hasan, S.; Nath, S.; Biswas, S. (2019). Phayre's Langur Population in Northeast Bangladesh: Underestimated and Under-pressure. Conference: Student Conference on Conservation Science (SCCS). Bengaluru, Karnataka.
  13. 1 2 3 Koenig, A.; Borries, C. (2011). "Social Organization and male residence pattern in Phayre's leaf monkeys". Long-Term Field Studies of Primates. pp. 215–236. doi:10.1007/978-3-642-22514-7_10. ISBN   978-3-642-22513-0.
  14. ↑ Gibson, L.; Koenig, A. (2012). "Neighboring groups and habitat edges modulate range use in Phayre's leaf monkeys (Trachypithecus phayrei crepusculus)". Behavioral Ecology and Sociobiology. 66 (4): 633–643. doi:10.1007/s00265-011-1311-2. JSTOR   41501760. S2CID   253806835.
  15. 1 2 3 Nigam P.; Nilofer B.; Srivastav A.; Tyagi P.C (2014). National Studbook of Phayre's leaf monkey (Trachypithecus phayrei) (Second ed.). Dehradun and New Delhi: Wildlife Institute of India and Central Zoo Authority.
  16. ↑ Lu, A.; Beehner, J.C.; Czekala, N.M.; Borries, C. (2012). "Juggling Priorities: Female Mating Tactics in Phayre's Leaf Monkeys". American Journal of Primatology. 74 (5): 471–481. doi:10.1002/ajp.22004. hdl: 2027.42/91119 . PMID   22318888. S2CID   9794.
  17. ↑ Lu, A.; Beehner, J.C.; Czekala, N.M.; Borries, C. (2010). "Reproductive characteristics of wild female Phayre's leaf monkeys". American Journal of Primatology. 72 (12): 1073–1081. doi:10.1002/ajp.20866. hdl: 2027.42/78228 . PMID   20677225. S2CID   10335911.
  18. ↑ Borries, C.; Lu, A.; Ossi-Lupo, K.; Larney, E.; Koenig, A. (2004). "The meaning of weaning in wild Phayre's leaf monkeys: last nipple contact, survival, and independence". American Journal of Physical Anthropology. 154 (2): 291–301. doi:10.1002/ajpa.22511. PMID   24615436.
  19. ↑ Parida, A.; Solanki, G.; Decemson, Ht. (2018). "Feeding Behavior of Phayre's Leaf Monkey (Trachypithecus phayrei) and Capped Langur (Trachypithecus pileatus) in Dampa Tiger Reserve, Mizoram". Science & Technology Journal. 6: 31–38. doi:10.22232/stj.2018.06.01.04.
  20. ↑ Majumdar, K.; Nath, A. J.; Gupta, A. K.; Datta, B. K. (2015). "Bamboo invasion: threat to primate conservation in North East India". Current Science. 108 (11): 1969–1971. JSTOR   24905551.
  21. ↑ Gupta, A. K. (2005). "Dietary differences between two groups of Phayre's Langur Trachypithecus phayrei in Tripura, India: Responses to food abundance and human disturbance". Journal of the Bombay Natural History Society. 102 (1): 3–9.
  22. ↑ Ahmed, T.; Hasan, S.; Nath, S. & Biswas, S. (2020). Population status of Phayre's Langur in northeastern forests of Bangladesh. Seventh Asian Primate Symposium & First International Conference on Human-Primate Interface. Gawahati, Assam.
  23. ↑ Gupta, A. K. (2000). "Shifting Cultivation and Conservation of Biological Diversity in Tripura, Northeast India". Human Ecology. 28 (4): 605–629. doi:10.1023/A:1026491831856. JSTOR   4603374. S2CID   153323209.
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