KASHMIR GRAY LANGUR

Semnopithecus ajax

Geographic Distribution and Habitat

The Chamba Valley of Himachal Pradesh, a mountainous state of northwestern India situated in the Western Himalayas, is home to the Kashmir gray langur (Semnopithecus ajax). Whether or not this leaf-eating monkey inhabits the region of Kashmir (one of the species’s namesakes) is uncertain. However, some wildlife biologists assert that Kashmir and the territory of Jammu (each claimed by both India and Pakistan) are included in this species’s restricted geographic distribution. Still other biologists include Melamchi, Nepal, in this primate’s range.

Surrounded by Chamba’s high peaks, Kashmir gray langurs inhabit a variety of habitats including subtropical, tropical, moist temperate, alpine cedar, coniferous and broadleaved forests, and subalpine scrublands, dwelling between 7,218 and 13,123 ft (2,200–4,000 m) above sea level. They live in fragmented populations with an extent of occurrence of less than 1,930 sq mi (5,000 sq km), occupying less than 193 sq mi (500 sq km) of the valleys in their rugged Himalayan mountain ecosystem. These monkeys opportunistically change their address, relocating to different habitats depending on the season and availability of food.

An Old World monkey with many aliases, the Kashmir gray langur is known also as the dark-eyed Himalayan gray langur, the Chamba sacred langur, and the Himalayan gray langur. It belongs to the primate family Cercopithecidae and subfamily Colobinae (Colobine), which includes all the Old World monkeys with folivorous feeding habits.

TAXONOMY IN TRANSITION

Prior to being upgraded to its own species status in 2001, the Kashmir gray langur had been considered a subspecies of the northern plains gray langur (S. entellus), another langur species with several aliases. But the time basking in its own limelight might be short lived. A group of scientists, in the course of their study on the impact of climate change on langur species throughout the Western Himalayas and Nepal, has concluded that the Kashmir gray langur, along with the Tarai gray langur (S. hector) and the Nepal gray langur (S. schistaceusare one single species. The scientists have suggested that these three aforementioned gray langur species be collectively referred to as the Himalayan gray langur, appropriating the genus and species name of the erstwhile Nepal gray langur (S. schistaceus) and applying them to this merged trio. The group’s findings are to be published in the June 2020 issue of the scientific journal Global Ecology and Conservation. In the meantime, and before this primate is possibly demoted from full species status, let’s celebrate the Kashmir gray langur.

Kashmir gray langur geographic range. Map: IUCN, 2020

Size, Weight, and Lifespan

Kashmir gray langurs are big monkeys, larger than other langur species. Males and females are both formidable in size, with a head-to-body length measurement of 26.4 in (67.1 cm) and an average weight of 39 lb (17.7 kg). A long tail that arcs over the back adds to their overall length.

Lifespan for this little-studied species has not been documented. Its cousin, the northern plains gray langur (whom scientists had once believed was a parent species to the Kashmir gray langur) is reported to live up to 30 years in captivity. In the wild, males don’t typically live past 18 year of age, while females live into their 30s.

What Does It Mean?

Extent of occurrence:
A parameter that measures the spatial spread of the areas currently occupied by the taxon. The intent behind this parameter is to measure the degree to which risks from threatening factors are spread spatially across the taxon’s geographical distribution.

Nonprehensile or Non-prehensile:
Incapable of grasping or gripping,

Visit the Glossary for more definitions

Appearance

These are striking primates, distinguished from other gray langur species by their immense size and darker-colored fore and hind limbs. The silvery-gray fur coat that cloaks their back and limbs is long and silky. In contrast, the chest and abdomen are dressed in white fur, with a hint of pale yellow. Dark eyes peer out from a hairless black face that is framed by a generous, “poofy,” silky white muffler that tries to conceal the monkey’s dark, hairless ears. Fingers are fitted with long, dark nails. The Kashmir gray langur’s long, nonprehensile tail, which it carries arched over its back and curved toward the head while walking on the ground, appears to have had the tip dipped in white paint, like an artist’s brush.

Photo credit: Francesco Veronesi/Flickr/Creative Commons
Diet

Kashmir gray langurs are primarily folivores; 85 percent of their diet comprises leaves, preferably mature leaves. But the capricious temperament of their Himalayan ecosystem, which can feature summertime monsoons and frigid winter temperatures and snowstorms, forces the langurs to adjust their diet accordingly.

These primates feast on leaves during the spring and summer months (February through June); their multi-chambered stomachs are specialized for digesting this roughage. Kashmir gray langurs also eat fruits, flowers, cultivated crops (which they raid from farmers’ fields), and seeds. Some of these seeds contain high levels of toxins and are prudently eschewed by other animals seeking a snack. Fortunately, the digestive system of these gray langurs has adapted to nullify the toxins and leave behind the nutrients, providing important supplementary sustenance. Tree bark is on the menu during winter months (November through March), when preferred foods are unavailable. Besides providing an alternative meal selection, tree bark offers medicinal value. The inherent plant compounds contain anti-inflammatory properties that help to protect the langurs’ immune system. Insects burrowing into the bark might also be consumed. During the monsoon months of July through September, when food is scarce, the langurs might overturn rocks in search of insect sustenance.

And though not a menu item, per se, Kashmir gray langurs have been observed eating body lice picked off a partner’s body during a social grooming session.

Behavior and Lifestyle

Although the Kashmir gray langur is one of the least-studied gray langur species, wildlife biologists have been fortunate to make limited direct observations. Further behavioral conclusions are based on observations of similar gray langur species.

These are primates who are both terrestrial (spending time on the ground) and arboreal (spending time in the trees). Gray langurs move quadrupedally (on all four limbs) and are inclined to run, rather than walk, whether on the ground or moving through trees. On the ground, they sometimes alternate running with walking a few steps between their gait. In the trees, they assume an upright stance and leap horizontally 12–15 ft (3.7–4.6 m) as they travel from branch to branch. Descending leaps can be as much as 35–40 ft (10.7–12.2 m). Gray langurs are also known to hop bipedally (standing upright, hopping on the two rear limbs). And they are capable of swimming, if they must. One wildlife study reports that after several langurs accidentally fell into water, they swam to the safety of solid ground.

Kashmir gray langurs are diurnal, meaning they are active during daylight hours. Activity budget for a typical day is spent accordingly: feeding (39.8 percent), resting (29.2 percent), traveling (17.5 percent), grooming (9.5 percent), and huddling (3.2 percent), with other activities filling any gap. Wildlife researchers have observed significant differences in the amount of time spent by male, female, and juvenile langurs in social activities and feeding. Males appear to spend more time feeding and foraging than females, and juveniles spend the most time in social activity such as play. Playing is more than a casual, fun pastime: it serves to develop physical and behavioral development, along with helping to develop social bonds. Wildlife researchers observed no significant time differences spent resting and traveling among troop members.

At night, Kashmir gray langurs sleep in trees that are up to 39.4 ft (12 m) tall, among the highest branches. They might also choose man-made structures like towers and utility poles in areas of human settlements.

Seasonal changes influence these primates’ behavioral strategies and their daily activity budget. As an example, during winter months Kashmir gray langurs spend far more time foraging (as available food is often hidden beneath snow cover) and spend less time resting. These large primates must fuel their bodies to maintain a stable internal core temperature, known in science-speak as “thermoregulation,” as they withstand harsh environmental conditions.

They might spend more time huddling in winter months. Known as “social thermoregulation,” group members who huddle together benefit from one another’s body heat; they are able to stay warmer, expend less energy, are less exposed to environmental stress, and increase their chances of surviving the winter.

A wildlife study published in 2018 presents the findings of a team of behavioral ecologists who studied huddling behavior in wild Barbary macaques in Morocco. Although these Old World primate cousins live on another continent than Kashmir gray langurs, the scientists posit that huddling behavior, which they classify as a form of social bonding, is connected to a higher level of “fitness,” a term the scientists use to measure how well wild animals cope with local ecological conditions as measured by their reproductive success and survival. They further conclude that wild monkeys who have multiple social (grooming) partners form larger huddles during adverse weather conditions, thereby increasing their chances of surviving brutal winters.

Fun Facts

Northern gray langur populations (including the Kashmir gray langur) carry their tail arced over their back, pointed forward as they walk; southern populations carry their tail pointed backward.

The Kashmir gray langur takes its scientific Latin name, Semnopithecus ajax, from a character in the ancient Greek epic poem The Iliad, set during the Trojan War. Ajax the Greater is son of Telamon and king of Salamis; Ajax the Lesser is son of Oileus, and commander of the Locrians. Some historians assert that the virile warrior Ajax the Greater is the more likely inspiration for the name of this langur species. Two other gray langur species take their Latin names from The IliadTarai gray langur (Semnopithecus hector) is named for Hector, Prince of Troy, son of King Priam, and the foremost Trojan warrior who engaged in combat with Ajax the Greater. The tufted gray langur (Semnopithecus priam) is named for Priam, the aged King of Troy.

Daily Life and Group Dynamics 

A survey conducted in 2017 recorded ten troops of 142 individuals, with troop size ranging from 3 to 27 members. Another detailed survey recorded an average group size of 16 to 18 individuals of both sexes, including adults and their offspring. (Membership increased slightly during the winter months.)

Unlike most other Asian colobine monkeys whose family groups are led by an adult male and several females and their offspring, Kashmir gray langur groups may include multiple males. All-male troops also occur.

Looking at other gray langur species, all-male troops tend to be the smallest and may consist of adults, subadults, and juveniles. However, social hierarchies exist for all group compositions. In all-male troops, aggression rules. In mixed groups with multiple males, male dominance is achieved through aggression and mating success. Females of a group are matrilineally related, having remained with their birth (or “natal”) group throughout their lives (unlike males, who leave their natal group upon reaching adulthood). Among sexually mature females, rank is based on physical fitness and age. Younger sexually mature females have higher ranking (similar to human primates, where younger females are often seen as more desirable and possess a certain kind of “power” to attract male partners). Nevertheless, relationships between the females of a group are usually friendly. They often forage, travel, and rest within one another’s company. Relationships between males, however, can range from peaceful to violent.

All members of a troop exhibit a strong attachment to their distribution areas (think of the adage “home sweet home”). In multi-male/multi-female troops, the average home range is from 0.9 to 2.1 sq mi (2.33–5.47 sq km). All-male groups typically have larger home ranges, averaging 1.5–2.3 sq mi (4.0–6.0 sq km).

Troop size and home range are directly linked. Smaller troops encompass a smaller home range, whereas larger troops encompass larger home ranges. Members of larger troops are forced to travel farther distances to forage to ensure that everyone is fed and their daily energy requirements are fulfilled.

Predator presence is a significant factor on troop size. Kashmir gray langurs are the preferred prey of leopards. Tigers find these large primates tasty, too. Asian wild dogs, known as dholes, also hunt the langurs. Wolves and golden jackals are thought to be predators as well.

Communication

While vocalizations specific to the Kashmir gray langur have not been reported, the following vocalizations are attributed to gray langur species, in general.

  • Loud calls or whoops, emitted by adult males during displays of might
  • Pant barks, emitted with loud calls by adult males when interacting with another group
  • Harsh barks, emitted by adult and subadult males when surprised by a predator
  • Cough barks, emitted by adult and subadult males and females while traveling as a group
  • Grunt barks, emitted primarily by adult males during group travel and intended to intimidate a potential threat
  • Honks, emitted by adult males when interacting with another group
  • Hiccups, emitted by group members when when they encounter another group
  • Rumble screams, emitted by group members when encountering a predator threat
  • Grunts, emitted by group members in a variety of situations
  • Rumbles, emitted by adult males and females prior to and during copulation

Mutual grooming between members is an important tactile communication that helps to establish social bonds with one another. For Kashmir gray langurs, higher-ranking females give and receive the most grooming sessions. They will also groom other females, regardless of rank. Lower-ranking females are more often the givers, rather than the recipients, in grooming sessions with males.

Posturing is an intimidation tactic, seen in high-ranking adult males during hostile encounters with other groups.

Reproduction and Family

If a group happens to be led by a lone male, he is the sole breeder. In multiple-male groups, the highest-ranking male fathers most of a group’s offspring. Next-ranking males are next in line for siring privileges. Higher-ranking females (the desirable copulation partners of males) are reproductively more successful than lower-ranking females.

Because it is not obvious when a female is in estrus, she must solicit the male to get his attention. Approaching her potential mating partner, she shudders her head, lowers her tail, and flashes her anogenital area for him to see. Not all solicitations are accepted by the male, however, and may not result in copulation.

Births occur from January through June, with nearly half of all infants born in March. The interbirth interval is 2.4 years. Gestation period in Kashmir gray langurs has not been reported. However, for northern plain langurs (close primate cousins), the average pregnancy is about 200 days (6.7 months) resulting in the birth of a single infant, although twins are sometimes born. As compared to other Asian colobines, Kashmir gray langur mothers nurse their babies for a much longer period, about 25 months. The typical weaning age for other gray langur species is 13 months. The longer weaning period for Kashmir gray langurs is related to the nutritional deficiency of their diet.

For the first five months of their lives, all members of a group might help with child care (a practice known as “alloparenting”). Males are usually protective of a group’s infants, but they are known to kill infants who are sired by other males, in a phenomenon known as “infanticide.” It’s worthy to note that these males spare the lives of their own offspring. Infanticide is common among gray langur species, and wildlife biologists posit that males engage in this deadly behavior in a strategic effort to gain exclusive mating rights of a group’s reproductive females. These males want to ensure that their gene pool continues. Most of these male baby killers are adult males who have immigrated into an existing group and have successfully driven out the resident high-ranking male(s). Because females who are nursing young infants are not able to reproduce, infanticide has the biological effect of returning the females to estrous, thereby providing males with the opportunity to mate. But females are clever and have their own strategy for protecting their infants. What may appear to be promiscuity is actually preservation. Knowing that males won’t kill their own offspring, females will deliberately mate with multiple partners, so as to confuse paternity.

Ecological Role

Through their folivorous diet, Kashmir gray langurs help to maintain the stability of their forest ecosystem. Their extensive leaf-eating “prunes” the trees from which they dine, thereby controlling vegetation throughout their environment.

Conservation Status and Threats

Due to their restricted range and small, fragmented populations, Kashmir gray langurs are classified as Endangered by the International Union for Conservation of Nature (IUCN, 2015), appearing on the IUCN Red List of Threatened Species. The total number of mature individuals is estimated to be less than 1,500 in number.

These large primates face multiple threats. Though far from trivial, their natural predators (leopards, tigers, wild dogs . . .) are the least of their worries. Humans pose the greatest threat to the species’s survival. Habitat loss and degradation due to human activity, hunting, direct conflict with humans, and incidental deaths all conspire to undermine the Kashmir gray langur’s place in our world.

Slash-and-burn agriculture, logging, mining, transformation of forestland into plantations, deliberately set fires, and pillaging Kashmir gray langur habitat to collect medicinal plants have destroyed and altered natural habitat.

Gray langurs are also kept as pets or used in religious ceremonies by Hindu priests. Others are hunted and killed for their flesh (known as “bushmeat”) or are killed and dismembered for their body parts, which are used either for medicinal purposes or as amulets intended to ward off evil spirits. Individuals might also be kidnapped and cheaply sold as biomedical research specimens to be experimented upon and deliberately infected with human diseases.

Increasingly, gray langurs are becoming regarded as pests, rather than as sacred beings, despite their presence outside of local temples where people leave food for them. It’s one thing for these monkeys to congregate on the grounds of temples, but people don’t want them inside their homes. Local farmers do not look kindly upon these primate crop raiders, who have become more brazen as more of the langurs’ natural habitat is destroyed. Foraging in a farmer’s field may likely get a langur killed.

Many langurs are struck and killed by automobiles; their bodies are routinely found in or alongside roadways that run through gray langur habitat. With the influx of humans comes human diseases that may be transmitted to the langurs. And the willful destruction of the tall trees where Kashmir gray langurs sleep at night have left them more vulnerable to their natural wild predators.

If human-caused disturbances were not enough to threaten the species, Kashmir gray langurs are also vulnerable to extreme weather conditions—beyond the brutal winters they endure. Periods of drought and monsoons can have severe impact on these langur populations. Human-induced climate change only makes these natural disasters worse.

Conservation Efforts

Kashmir gray langurs are listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. The species is also included in Schedule II, Part I, of the Indian Wildlife Protection Act of 1972, amended up to 2002. This legislation forbids killing and capture of these gray langurs. Unfortunately, laws enacted to protect wildlife species are not always enforced—even when a species lives in a protected area. Two protected areas where Kashmir gray langurs reside are Machiara National Park and Dachigam National Park (Kishtwar National Park). Unfortunately for these endangered primates, these parks are located within areas of political turmoil.

Furthermore, the local citizenry may be unaware that the Kashmir gray langur is a protected species.

In an effort to conserve this species, wildlife biologists call for deeper investigation into its taxonomy and life history, further survey studies, limiting factor research (studies on the variables that constrain the size of a population), and exploration of the Kashmir gray langur’s behavioral ecology (the relationship between an animal’s behavior and the conditions of its environment). Monitoring the gray populations and engaging the local citizenry through education programs are additional key imperatives in saving the Kashmir gray langur.

References:
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4627992:
  • Mir, Z. R., Noor, A., Habib, B., & Veeraswami, G. G. (2015). Seasonal population density and winter survival strategies of endangered Kashmir gray langur (Semnopithecus ajax) in Dachigam National Park, Kashmir, India. SpringerPlus4, 562
  • https://www.researchgate.net/publication/322156725_Semnopithecus_ajax_Pocock_1928_a_Critically_Endangered_Species_Struggling_for_Space_and_Survival_in_Nature:
  • Thakur, DR  Himachal Pradesh University Journal of Wildlife Research | July-September, 2017 | Volume 05 | Issue 03 | Pages 32-40 © 2017 Jakraya
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  • Sharma  and  Ahmed…  Distribution  of Endangered  Kashmir  Gray  Langur (Semnopithecus  ajax)  in Bhaderwah, Jammu and Kashmir, India. Journal of Wildlife Research | January-March, 2017 | Vol 5 | Issue 1 | Pages 01-05 
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Written by Kathleen Downey, June 2020