Lar gibbon

Advisory

We are currently in the process of updating this factsheet. Recent developments in our understanding of this primate may not be reflected in the content available today. If you’d like to contribute to writing, editing or peer-reviewing PIN content, please don’t hesitate to get in touch!

TAXONOMY

Suborder: Haplorrhini
Infraorder: Simiiformes
Superfamily: Hominoidea
Family: Hylobatidae
Genus: Hylobates
Species: H. lar
Subspecies: H. l. carpenteri, H. l. entelloides, H. l. lar, H. l. vestitus

Other names: H. albimana, H. longimana, H. variegates, H. varius, common gibbon, lar gibbon, white-handed gibbon; withandgibbon (Dutch); gibbon à mains blanches, gibbon lar (French); gibbon de manos blancas (Spanish); lar, vanlig gibbon, vithandad gibbon (Swedish); H. l. carpenteri: Carpenter’s lar; H. l. entelloides: central lar; H. l. lar: Malaysian lar; H. l. vestitus: Sumatran lar.

Conservation status:  multiple…

Life span: up to 50 years (captive)
Total population: 15,000-20,000 (Thailand)
Regions: Southeast Asia
Gestation: approx. 6 months
Height: 43.5 to 58.5 cm (M), 42.0 to 58.0 cm (F)
Weight: 5.0 to 7.6 kg (M), 4.4 to 6.8 kg (F)

The subspecific status of the Yunnan lar, H. l. yunnanensis, is doubtful as it is likely synonymous with H. l. carpenteri and as such, is not considered as a subspecies here (Geissmann 1995; Brandon-Jones et al. 2004; Groves & Geissmann pers comm. cited in Geissmann 2007). Some publications still do consider H. l. yunnanensis a valid subspecies, however all of this may be moot as the populations which may have made up H. l. yunnanensis are in all likelihood extinct (Geissmann 2008). All subspecies need to be better defined and are not highly distinct (Brockelman & Geissmann 2008).

MORPHOLOGY

Three Lar gibbons in a tree
Hylobates lar

Lar gibbons weigh on average between 5.0-7.6 kg (11.0-16.8 lb)(M) and 4.4-6.8 kg (9.7-15.0 lb) (F). Head and body lengths range from 43.5-58.5 cm (17.1-23.0 in) (M) and 42.0-58.0 cm (16.5-22.8 in) (F) (Roonwal & Mohnot 1977). Like all apes, lar gibbons have no tail and also possess small ischial callosities as well as long arms suited for brachiation (Ankel-Simons 2007).

Pelage is creamy, brown, or black in both sexes and at all ages (Roonwal & Mohnot 1977; Mootnick 2006; Bartlett 2009). Adults have a ring around the hairless face (less apparent in lighter individuals) and have white feet and hands that contrast with the rest of the body (Marshall & Sugardjito 1986; Groves 2001; Mootnick 2006; Ankel-Simons 2007; Bartlett 2009). Individuals are either light or dark in overall color (often called light and dark phases), with light individuals having buff or creamy pelage, and dark individuals with brown or black pelage (Groves 2001). The deciding factor whether a lar gibbon is dark or light is simple genetic inheritance from its parents, in which the dark form is the dominant allele (Brockelman 2004). The proportion of dark to light individuals varies in lar gibbons, with some populations being mostly light and others being mostly dark and with various proportions in-between, often varying greatly between populations (Marshall & Sugardjito 1986; Brockelman 2004). Mating is random with respect to pelage color (Brockelman 2004).

H. l. carpenteri are long-haired and almost black or brownish charcoal in the dark form and are creamy white or white-buff in the light form (Groves 2001; Mootnick 2006). H. l. entelloides are black or black-brown in the dark form and honey-colored in the light form with darker legs (Groves 2001; Mootnick 2006). H. l. lar are medium brown or dark chocolate brown in the dark form with a lighter torso and darker legs (Groves 2001; Mootnick 2006). This subspecies is creamy in the light form (Groves 2001). H. l. vestitus are always light with no dark form and are typically light brown, with a buff back, pale lower back and a brown head, ventrum and limbs (Marshall & Sugardjito 1986; Groves 2001). However, due to variation across their distribution, if a specific lar gibbon’s place or origin is unknown, it is difficult to assign it subspecifically based on morphology (Geissmann 1995). Morphological differences between subspecies need to be further documented (Brandon-Jones et al. 2004).

Lar gibbons are adapted for arboreal locomotion and usually move through their environment using brachiation, but also through other forms of movement (Roonwal & Mohnot 1977; Vereecke et al. 2006). These include walking (bipedal, tripedal, and quadrupedal), hopping, running (bipedal, tripedal, and quadrupedal), climbing, swinging, bridging and leaping (Baldwin & Teleki 1976; Carpenter 1976). Lar gibbons are also capable of rapid terrestrial movement using 7 types of gait even though they are adapted for arboreal locomotion (Vereecke et al. 2006).

In captivity, lar gibbons have lived up to around 50 years of age (Weigl 2005).

RANGE

CURRENT RANGE MAPS (IUCN REDLIST):
Hylobates lar | Hylobates lar carpenteri | Hylobates lar lar | Hylobates lar vestitus | Hylobates lar entelloides | Hylobates lar yunnanensis

Lar gibbons are mainly found in Southeast Asia and in a small portion of South Asia. They have the greatest north-south range of any of the gibbons (Bartlett 2007). The species is found in Indonesia, Laos, Malaysia, Myanmar and Thailand (Brandon-Jones et al. 2004). Lar gibbons are probably extinct in China but if they still exist, they would only be found in Southwest Yunnan, their former range (Brandon-Jones et al. 2004; Brockelman & Geissmann 2008; Geissmann 2008). Moving south from southwest Yunnan, lar gibbons are found in the majority of Thailand excepting the north-eastern areas of the country. The range extends south through southern and eastern Myanmar but only east of the Salween River (Brockelman & Geissmann 2008). They are found through the Malay Peninsula except for a discontinuity in their distribution between the Perak and Muda Rivers, very roughly near the Thai-Malay border (Brockelman & Geissmann 2008). Lar gibbons also exist west of the Mekong River in northwestern Laos and in northern Sumatra (Brandon-Jones et al. 2004; Brockelman & Geissmann 2008). Subspecifically, H. l. lar are found in peninsular Malaysia and possibly Thailand. H. l. carpenteri is found in Myanmar, west Laos, and north Thailand. H. l. entelloides is found in southeast Myanmar, and in central and south Thailand (Brandon-Jones et al. 2004). In Indonesia, H. l. vestitus is found over the northern third of the island of Sumatra (MacKinnon 1984; Brandon-Jones et al. 2004; Brockelman & Geissmann 2008).

In Thailand, there are probably between 15,000-20,000 lar gibbons (Geissmann 2007).

HABITAT

In general, lar gibbons are found in lowland dipterocarp forest, hill dipterocarp forest, and upper dipterocarp forests, including primary lowland and submontane rainforest, mixed deciduous bamboo forest, and seasonal evergreen forests, but are not usually found higher than 1200 meters above sea level (Chivers 1972; Ellefson 1974; Caldecott 1980; Palombit 1992; Ungar 1996; Reichard & Sommer 1997; Brockelman et al. 1998; Yimkao & Srikosamatara 2006; Bartlett 2009). Lar gibbons are also found in peat swamp forest (Norhayati et al. 2004).

Perhaps the most important study site of lar gibbons is at Khao Yai, Thailand, northeast of Bangkok, home to many studies (some long-term) since the 1970’s (Brockelman et al. 1998; Bartlett 2009). The vegetation type at this site is mostly seasonally wet evergreen rainforest (Brockelman et al. 1998; Bartlett 2009). Three seasons are experienced in this part of Thailand; a cool season (November to February), a hot season (March-May) and a wet season (June-October) (Bartlett 2009). Annual rainfall at this site averages between 200 and 300 cm (78.7 and 118.1 in) (mostly falling June-September) and daytime high temperatures usually average between 25°C and 30°C (77°F and 86°F) year-round. The coldest lows are usually no colder than 10°C (50°F) (Tangtham 1991 cited in Bartlett 2009; Bartlett 2009).

Lar gibbons are usually found high in the canopy and are rarely found in the understory (Ungar 1996). At Khao Yai, the average height of feeding trees was 23.7 meters (77.8 ft) (Bartlett 2009).

ECOLOGY

Lar gibbons eat a large variety of foods, especially fruit, including figs and other small, sweet fruits, liana fruit, tree fruit and berries but also young leaves, buds & flowers, new shoots, vines, vine shoots, insects including mantids and wasps, and even birds’ eggs (Carpenter 1940; Ellefson 1974; Raemaekers 1979; MacKinnon & MacKinnon 1980; Ungar 1995; Palombit 1997; Yimkao & Srikosamatara 2006; Bartlett 1999; 2009). They are known to eat parts of over 100 species of plants (Bartlett 1999; 2009). In general, when data is combined among study sites, the lar gibbon diet includes fruit (66%), leaves (24%), flowers (1%), and insects (9%) although in individual studies there can be some significant variation by locality (see review in Bartlett 2007; Bartlett 2007). Figs often make up a large proportion of the diet, on average around 27%, but sometimes up to half of the total foods eaten (Palombit 1997; Bartlett 2007). Feeding on figs increases during times that other preferred resources are scarce (Bartlett 1999). Food transfer between lar gibbons has been seen often accompanied by begging of one animal for food from another (Nettelbeck 1998). Most leaves that are eaten are young. One method that lar gibbons drink water is from tree holes by cupping their hands (Bartlett 1999).

Lar gibbon
Hylobates lar

Diet can vary quite a bit with the seasons. For example, at Khao Yai, non-fig fruits dominated in the diet through the year excepting November and December. At this study site, flowers are most available during the cool season, while ripe fruit is most abundant during the hot and wet seasons. At this study site, ripe fruit is preferred when available, with the variability of the diet increasing when ripe fruit is less available during the cool season. However, fruit including figs never fell below 50% of the diet year-round (Bartlett 2009).

Food competition may exist between lar gibbons and pigtail macaques (Macaca nemestrina) as the two species have been seen foraging near one another and sometimes interacting (Whitington 1992). Feeding competition between lar gibbons and long-tailed macaques (M. fascicularis) and dusky leaf monkeys (Trachypithecus obscurus) has also been seen (Ellefson 1974). Lar gibbons compete with sympatric siamangs (Symphalangus syndactylus), the presence of which usually causes conflict and probably reduces the foraging success of lar gibbons (Palombit 1996).

Diurnal lar gibbons in Thailand are active for an average of 8.7 hours per day, leaving their sleeping sites right around sunrise and entering sleeping tress an average of 3.4 hours before sunset (Bartlett 2009). On average, lar gibbons spend their days feeding (32.6%), resting (26.2%), traveling (24.2%), in social activities (11.3%), vocalizing (4.0%) and in inter-group encounters (1.9%), although actual proportions of activities can change significantly over the course of the year (Bartlett 2009). Daily, if the morning is clear before dawn, an adult male will solo call, usually from its sleeping tree. At sunrise, all group gibbons will awaken, then defecate and urinate while hanging from a branch. Usually, the group will then move to a feeding tree. There is normally a duet call among the adult pair before noon and the rest of the day is spent alternating between feeding and traveling to new trees to feed. With seasonal reductions in the amount of available fruit, feeding time increases and, correspondingly, less time is spent in social activities (Bartlett 2009). A group pause for about an hour of rest and social activities usually occurs each day (Bartlett 2009). During the cool season, lar gibbons can often be found for up to several hours a day in big fig trees (Bartlett 2009).

Average home range is 0.4 km² (0.15 mi²), with a daily path length of 1.4 kilometers (0.87 mi) although there is considerable variation among study sites (Bartlett 2007). Daily path length tends to increase with increased fruit availability (Bartlett 1999). Group progressions at some locations are usually led by the adult male, while at other sites females may do so, and coordinate group movements as well (Yimkao & Srikosamatara 2006; Barelli et al. 2008a). Within the home range is a territory defended from other groups averaging around 76% of the home range (Bartlett 2007). The home ranges of different groups often overlap, sometimes extensively (Ellefson 1974; Reichard & Sommer 1997; Bartlett 1999).

Sleeping trees are not manipulated and group members usually sleep one to a tree nearby each other. Often the tallest trees available are chosen for sleeping and lar gibbons try to avoid notice when moving to sleeping sites, possibly as a way of reducing predation (Reichard 1998). Often, sleeping trees are located on steep slopes or on cliffs (Yimkao & Srikosamatara 2006).

There are a number of potential predators of adult or infant lar gibbons. These may include clouded leopards (Neofelis nebulosa), marbled cats (Pardofelis marmorata), Asian golden cats (Catopuma temmincki), leopard cats (Prionailurus bengalensis) tigers (Panthera tigris), leopards (Panthera pardus), pythons (Python sp.), hawk eagle species (Spizaetus sp.), black eagles (Ictinaetus malayensis), and crested sepent eagles (Spilornis cheela) (Reichard 1998; Uhde & Sommer 2002). White-bellied sea eagles (Haliaeetus leucogaster) are also capable of taking a lar gibbon (Ellefson 1974). Lar gibbons may mob and chase off potential predators (Reichard 1998; Uhude & Sommer 2002).

While the specific composition of the primate community varies across the distribution of the lar gibbon, the species can be found living in sympatry with several other primates and apes, including orangutans (Pongo pygmaeus), siamangs (S. syndactylus), pileated gibbons (Hylobates pileatus), purple-faced langurs (Trachypithecus sp.), Thomas’s langur (Presbytis thomasi), slow loris (Nycticebus coucang), and several macaque species (Macaca sp.) (Ellefson 1974; Geissmann 1991; Palombit 1992; Ungar 1995; Palombit 1996; Bartlett 1999; Yimkao & Srikosamatara 2006).

Content last modified: November 17, 2010

Written by Kurt Gron. Reviewed by Alan Mootnick.

Cite this page as:
Gron KJ. 2010 November 17. Primate Factsheets: Lar gibbon (Hylobates lar) Taxonomy, Morphology, & Ecology . <http://pin.primate.wisc.edu/factsheets/entry/lar_gibbon/taxon>. Accessed 2020 July 21.

 

SOCIAL ORGANIZATION AND BEHAVIOR

Lar gibbons usually live in serial monogamous pairs with up to 4 offspring in each group (Palombit 1996; Bartlett 2007; Reichard 2003; Reichard & Barelli 2008). While group living in serial monogamous pairs is the norm, it is not the rule, and at some sites there are also multi-male groups as well as groups with multiple adult females (Reichard 2003; Barelli et al. 2008b; Reichard & Barelli 2008). Long-term data indicate that females may live in several different types of groups (e.g. pair or multi-male) over their lifetimes (Reichard & Barelli 2008). At one location, multi-male groups comprised over 20% of groups present (Reichard & Barelli 2008). Extra-pair copulations have been seen on a number of occasions (Reichard 1995; Reichard & Sommer 1997; Reichard 2003). In fact, at Khao Yai, most females are polyandrous as opposed to monogamous, even females in a single-male group (Barelli et al. 2008b; Reichard & Barelli 2008). In other words, social relationships are flexible (Reichard 1995; Reichard & Barelli 2008). In the case of individual pair-bonds, changes can result from desertion (often for another mate), replacement of one of a pair by a peripheral individual, disappearance or the death of one of the adult lar gibbons (Palombit 1994; Brockelman et al. 1998). Changes in pair composition can be common (Palombit 1994).

Within-group behavior is variable throughout the year, from almost a fifth of the activity budget to only a small percentage, with more social activity occurring at times of increased ripe fruit abundance. The three predominant types of within-group social interaction include grooming, play (wrestling, chasing, and slapping and biting), and social contact, with grooming the most common. Within-group aggression is rare and in general, immature lar gibbons play more than adults (Bartlett 2003). There are some indications that allogrooming serves more a hygienic than social function in lar gibbons and tends to be reciprocal between individuals (Ellefson 1974; Reichard & Sommer 1994).

Encounters between different groups of lar gibbons can range between agonistic (physical altercations) and friendly (between-group playing or grooming) interactions (Reichard & Sommer 1997; Bartlett 2003). Most interactions between groups are agonistic, but can be purely vocal and even neutral in which both groups coming into contact barely react to one another (Bartlett 2003). Groups may also travel, feed or rest together when they come into contact (Reichard & Sommer 1997).

Males mainly participate in most territorial disputes, but females are sometimes approached by males during intergroup interactions (Reichard & Sommer 1997; Bartlett 2009). Disputes generally occur near the boundaries of the home range when two groups are in visual contact with one another and typically last around an hour (Bartlett 2003). Most inter-group interactions are accompanied by vocalizations (Reichard & Sommer 1997). The variability of the nature of interactions between neighboring groups may partly be the result of variable social and kin relationships between members of neighboring groups (Bartlett 2003). However, inter-group interactions can be quite violent, and there is evidence that wounds incurred in territorial aggression have resulted in the death of combatants (Palombit 1993). There is seasonal variation in the occurrence of inter-group encounters and territoriality may function in resource defense (Bartlett 2009).

Lar gibbon mother and infant
Hylobates lar

There is no personal leadership of a lar gibbon group, although adult females lead group progressions most often (Barelli et al. 2008a).

In one long-term study, males dispersed from their natal groups at around 10 years of age and usually attain a territory by replacing one of their resident adults. Dispersal distances are usually around one or two territories from the natal territory; averaging in one population 0.71km (0.44 mi) (Brockelman et al. 1998).

REPRODUCTION

While lar gibbons usually live in serial monogamous pairs, their reproductive system is complex and can be polyandrous, sometimes including flexible sexual relationships which often occur outside of the usual pair bond (Reichard 1995; Reichard & Barelli 2008). Polygamous mating has also been seen (Bartlett 2007). This is primarily due to the changing relationships among lar gibbons over their lifetimes, often including successive pairings with different mates and inclusion in different social group types (Reichard & Barelli 2008). However, in the case of extra-pair copulation by females, frequency of copulation remains much higher with the pair-mate than with other males (Barelli et al. 2008b). Mating occurs in every month of the year, but most conceptions occur during the dry season (March) with a peak in births during the late rainy season, in October (Barelli et al. 2008b; Savini et al. 2008).

Lar gibbon females exhibit swelling, protrusion and color change of the sex-skin beginning several days before ovulation and ending after ovulation, usually lasting around 7-11 days (Dahl & Nadler 1992; Barelli et al. 2007). Pregnant females also show sexual swelling, but at random times during pregnancy (Barelli et al. 2007).

Female solicitation postures include placing herself in front of a male and looking back at him, presenting her genitals to a male (Ellefson 1974; Barelli et al. 2008b). Copulation is dorso-ventral, with the male behind the female (Ellefson 1974). Females may refuse copulation by moving away from the male, vocalizing, or agonistically refusing the advances of the male (Barelli et al. 2008b).

On average, females reproduce for the first time at about 11 years of age in the wild, much later than in captivity (Reichard & Barelli 2008). The average reproductive cycle is 21.1 days long (Barelli et al. 2007). At a minimum, the interbirth interval is 3 years, and averages 41 months (Brockelman et al. 1998; Reichard & Barelli 2008). Gestation in wild lar gibbons is around six months (Barelli et al. 2007).

Male-male mounting has been observed among wild male lar gibbons (Edwards & Todd 1991).

PARENTAL CARE

In general, observations of lar gibbon births and infant development are extremely limited. At birth, lar gibbons weigh on average 383.4g (13.5oz) and are nearly naked. They are able to vocalize soon after birth (Crandall 1964; Ellefson 1974; Geissmann & Orgeldinger 1995). At one study site in Thailand, births showed a peak at the rainy season/dry season transition in September and October (Reichard & Barelli 2008). In the wild, infants are carried by clinging to their mother’s ventrum (Ellefson 1974). One infant in the wild did little more than cling to the female for the first several weeks of life (Ellefson 1974). One wild individual first ingested solid foods in the fourth month of life, timing also seen in captivity (Ellefson 1974; Roberts 1983). Also around this time, one wild infant started moving a short distance from its mother (Ellefson 1974). While uncommon, a measure of parental care of an infant was seen in captivity including predominantly play behaviors (Clemens et al. 2008). The ability to brachiate was first seen in a captive infant around 9 months of age (Roberts 1983).

Infants are weaned around two years of age (Ellefson 1974; Reichard & Barelli 2008).

Infant mortality is low, under 10% (6.3%) in the first year of life (Reichard & Barelli 2008).

COMMUNICATION

Lar gibbon
Hylobates lar

Lar gibbons have seven basic vocalization note types. These include the “wa”, “hoo”, “leaning wa”, “oo”, “sharp wow”, “waoo” and “other” type of vocalization (Raemaekers et al. 1984; Clarke et al. 2006). These basic types are usually assembled into longer phrases (Clarke et al. 2006). There are a number of types of call bout emitted by lar gibbons in different contexts. These include normal duets (structured vocalizations given by the mated pair usually during the mid-morning or afternoon), “ooaa” duets (similar to normal duets but rarer), calls emitted when disturbed (e.g. when predators are seen, in times of alarm, during territorial disputes or conflict), adult male solos (often given early in the day, near dawn or before), subadult male solos, adult female solos (given by mated females when isolated), and contact calls (Raemaekers et al. 1984; Raemaekers & Raemaekers 1985). Pair duets are very loud, and can be heard as far as several kilometers away (Reichard 1998). Subadult males have been known to interact with one another through solo calling as well (Raemaekers & Raemaekers 1984a). Once uttered by a pair, “ooaa” duets are infectious through the forest, often initiating similar vocalizations from other lar gibbons within earshot (Raemaekers & Raemaekers 1984b).

Most calling occurs in the morning (Yimkao & Srikosamatara 2006). Vocalization is heard in almost all intergroup encounters, including male solos, duets, and female solos (Reichard & Sommer 1997). Duet calls probably serve to reinforce the bond between the mated pair, but also to exclude other gibbon individuals (Raemaekers et al. 1984). Duets also function in distant vocal communication with other lar gibbon groups and in territorial defense (Raemaekers & Raemaekers 1984b). The duet culminates in the female’s great call and is given from anywhere in the territory (Raemaekers et al. 1984). The great call of an individual female is distinct and unique from the great calls given by other females (Yimkao & Srikosamatara 2006). In one study, vocal exchanges between males were the only form of interaction in 20% of inter-group encounters (Bartlett 2003). In addition, vocal behavior in general functions in the complex sexual competition within the species (Clarke et al. 2006). With habitat disturbance due to logging, calling frequency decreases (Johns 1985).

Female sexual swellings visibly communicate information about reproductive condition (Barelli et al. 2007). Male display behavior to increase conspicuousness includes one-arm dangles, locomotion back and forth around a particular pathway, and the breaking of branches (Ellefson 1974). Grimaces (exaggerated smiles) indicate subordination while open-mouth threats indicate an agonistic threat. Branch-jerks occur when a dominant gibbon shakes a branch and elicits submission from another individual (Ellefson 1974).

Content last modified: November 17, 2010

Written by Kurt Gron. Reviewed by Alan Mootnick.

Cite this page as:
Gron KJ. 2010 November 17. Primate Factsheets: Lar gibbon (Hylobates lar) Behavior . <http://pin.primate.wisc.edu/factsheets/entry/lar_gibbon/behav>. Accessed 2020 July 21.

INTERNATIONAL STATUS

CITES: Appendix I (What is CITES?)
IUCN Red List: H. lar, H. lar carpenteri, H. lar lar, H. lar vestitus: EN; H. lar entelloides: VU; H. lar yunnanensis: DD (What is Red List?)
Key: EN = Endangered, EN = Endangered, EN = Endangered, EN = Endangered, VU = Vulnerable, DD = Data deficient
(Click on species name to see IUCN Red List entry, including detailed status assessment information.)

Lar gibbon in a tree
Hylobates lar

In general, reintroduction of gibbons has not met with widespread success. Hopefully however, improved reintroduction methods may increase the success rate of rehabilitation and reintroduction of lar gibbons (Harding 1998). Further, the lar gibbon populations in China, sometimes classified as H. l. yunnanensis, appear to be extinct in the nation (Geissmann 2008). The Khao Yai national park, a site of long-term studies of lar gibbons, is part of the Dong Phayayen-Khao Yai Forest Complex, which has been designated as a UNESCO World Heritage Forest (http://www.unesco.org).

CONSERVATION THREATS

Threat: Human-Induced Habitat Loss and Degradation

Habitat loss due to a number of different threats endangers gibbons in general, including lar gibbons (Bartlett 2009). Lar gibbon habitats are threatened by forest clearance for the construction of roads (even in reserves and especially for a network in northern Sumatra), shifting agriculture, nature tourism, domestic cattle and elephants, annual forest fires, subsistence tree cutting, illegal logging, new village settlement, and for palm oil plantations (Yimkao & Srikosamatara 2006; Geissmann 2007). Habitat destruction due to logging and agriculture is a serious problem in Myanmar, while Thai forest loss is mainly attributable to illegal logging and encroachment (Nwe et al. 2005; Eudey 1994). Commercial development, even within protected areas, is starting to become a problem and may threaten lar gibbons as well (Bartlett 2009). In Sumatra, road building and paving has increased illegal farming and settlements, even within protected areas (Palombit 1992).

Threat: Harvesting (hunting/gathering)

Hunting for food is also a major threat to lar gibbon populations, partially due to the fact that the species is relatively easy to hunt (Yimkao & Srikosamatara 2006; Geissmann 2007). In Myanmar for example, primates, including lar gibbons, are hunted with blowguns, firearms, and dogs. Lar gibbons taken from such hunts are consumed for food, used for medicine, or exported (Nwe et al. 2005). In Thailand, the decrease in forest cover has seen has increased hunting (Eudey 1994). Lar gibbons have traditionally been subsistence hunted by hill tribes in Thailand (Eudey 1991-1992). In Sumatra, some locals have a religious prohibition against hunting lar gibbons or primates in general (Palombit 1992). However, taboos against hunting gibbons in some habitats appear to be breaking down (Yimkao & Srikosamatara 2006).

Lar gibbons are also collected as pets, a practice that impacts wild populations (Geissmann 2007). In fact, they are considered to be appealing as pets because they can be quite tame in captivity (Eudey 1991-1992). In Thailand, for example, lar gibbons are often kept as pets in both rural and urban areas and are sometimes found in animal markets for sale (Eudey 1991-1992; 1994). As infant lar gibbons are preferred as pets, often the mother is shot and killed to gain access to the infant, severely affecting the population dynamics of the species (Eudey 1991-1992; 1994).

LINKS TO MORE ABOUT CONSERVATION

CONSERVATION INFORMATION

CONSERVATION NEWS

ORGANIZATIONS INVOLVED IN Hylobates lar CONSERVATION

Content last modified: November 17, 2010

Written by Kurt Gron. Reviewed by Alan Mootnick.

Cite this page as:
Gron KJ. 2010 November 17. Primate Factsheets: Lar gibbon (Hylobates lar) Conservation . <http://pin.primate.wisc.edu/factsheets/entry/lar_gibbon/cons>. Accessed 2020 July 21

The following references were used in the writing of this factsheet. To find current references for H. lar, search PrimateLit.

REFERENCES

Ankel-Simons F. 2007. Primate Anatomy: an introduction, 3rd Edition. San Diego: Elsevier Acad Pr. 724 p.

Baldwin LA, Teleki G. 1976. Patterns of gibbon behavior on Hall’s Island, Bermuda. Gibb Siam 4:21-105.

Barelli C, Boesch C, Heistermann M, Reichard UH. 2008a. Female white-handed gibbons (Hylobates lar) lead group movements and have priority of access to food resources. Behaviour 145(7):965-81.

Barelli C, Heistermann M, Boesch C, Reichard UH. 2008b. Mating patterns and sexual swellings in pair-living and multimale groups of wild white-handed gibbons, Hylobates lar. Anim Behav 75(3):991-1001.

Barelli C, Heistermann M, Boesch C, Reichard UH. 2007. Sexual swellings in wild white-handed gibbon females (Hylobates lar) indicate the probability of ovulation. Horm Behav 51(2):221-30.

Bartlett TQ. 1999. Feeding and ranging behavior of the white-handed gibbon (Hylobates lar) in Khao Yai National Park, Thailand. PhD dissertation, Washington University, St. Louis. 193p.

Bartlett TQ. 2009. The gibbons of Khao Yai: seasonal variation in behavior and ecology. Upper Saddle River (NJ):Pearson Prentice Hall. 170p.

Bartlett TQ. 2007. The Hylobatidae: small apes of Asia. In: Campbell CJ, Fuentes A, MacKinnon KC, Panger M, Bearder SK, editors. Primates in perspective. New York:Oxford U Pr. p274-89.

Bartlett TQ. 2003. Intragroup and intergroup social interactions in white-handed gibbons. Int J Primatol 24(2):239-59.

Brandon-Jones D, Eudey AA, Geissmann T Groves CP, Melnick DJ, Morales JC, Shekelle M, Stewart C-B. 2004. Asian primate classification. Int J Primatol 25(1):97-164.

Brockelman WY, Reichard U, Treesucon U, Raemaekers JJ. 1998. Dispersal, pair formation and social structure in gibbons (Hylobates lar). Behav Ecol Sociobiol 42(5):329-39.

Brockelman W, Geissmann T. 2008. Hylobates lar [Internet]. 2008 IUCN Red List of Threatened Species [cited 2009 Jan 8]. Available from: http://www.redlist.org.

Brockelman WY. 2004. Inheritance and selective effects of color phase in white-handed gibbons (Hylobates lar) in central Thailand. Mamm Biol 69(2):73-80.

Caldecott JO. 1980. Habitat quality and populations of two sympatric gibbons (Hylobatidae) on a mountain in Malaya. Folia Primatol 33:291-309.

Carpenter CR. 1940. A field study in Siam of the behavior and social relations of the gibbon (Hylobates lar). Comp Psychol Mono 16(5):1-212.

Carpenter CR. 1976. Suspensory behavior of gibbons Hylobates lar. Gibb Siam 4:1-20.

Chivers DJ. 1972. The siamang and the gibbon in the Malay Peninsula. Gibb Siam 1:103-35.

Clarke E, Reichard UH, Zuberbühler K. 2006. The syntax and meaning of wild gibbon songs. PLoS One 1(1):e73.

Clemens Z, Merker B, Ujhelyi M. 2008. Observations on paternal care in a captive family of white-handed gibbons (Hylobates lar). Gibb J 4:46-50.

Crandall LS. 1964. The management of wild mammals in captivity. Chicago:The University of Chicago Pr. 761p.

Dahl JF, Nadler RD. 1992. Genital swelling in females of the monogamous gibbon, Hylobates (H.) lar. Am J Phys Anthropol 89(1):101-8.

Edwards A-MAR, Todd JD. 1991. Homosexual behaviour in wild white-handed gibbons (Hylobates lar). Primates 32(2):231-6.

Ellefson JO. 1974. A natural history of white-handed gibbons in the Malayan peninsula. Gibb Siam 3:1-136.

Eudey AA. 1991-1992. Captive gibbons in Thailand and the option of reintroduction to the wild. Prim Conserv 12-13:34-40.

Eudey AA. 1994. Temple and pet primates in Thailand. Rev Ecol Terre Vie 49(3):273-80.

Geissmann T. 2008. Auf der suche nach Chinas letzten weisshandgibbons: ein projektbericht aus dem Nangunhe-Naturreservat in der provinz Yunnan. Gibb Cons Allian Jahresbericht 4:10-21.

Geissmann T. 1995. Gibbon systematics and species identification. Int Zoo News 42(8):467-501.

Geissmann T, Orgeldinger M. 1995. Neonatal weight in gibbons (Hylobates spp.). Am J Primatol 37(3):179-89.

Geissmann T. 2007. Status reassessment of the gibbons: results of the Asian primate red list workshop 2006. Gibb J 3:5-15.

Geissmann T. 1991. Sympatry between white-handed gibbons (Hylobates lar) and pileated gibbons (H. pileatus) in southeastern Thailand. Primates 32(3):357-63.

Groves CP. 2001. Primate taxonomy. Washington, D.C.:Smithsonian Institution Pr. 350p.

Harding JL. 1998. The first stage of rehabilitation of a family of white handed gibbons Hylobates lar. Australas Primatol 12(2):2-8.

Johns AD. 1985. Behavioral responses of two Malaysian primates (Hylobates lar and Presbytis melalophos) to selective logging: vocal behavior, territoriality, and nonemigration. Int J Primatol 6(4):423-33.

MacKinnon JR. 1984. The distribution and status of gibbons in Indonesia. In: Preuschoft H, Chivers DJ, Brockelman WY, Creel N, editors. The lesser apes: evolutionary and behavioural biology. Edinburgh (UK):Edinburgh U Pr. p16-8.

MacKinnon JR, MacKinnon KS. 1980. Niche differentiation in a primate community. In: Chivers DJ, editor. Malayan forest primates: ten years’ study in tropical rain forest. New York:Plenum Pr. p167-90.

Marshall J, Sugardjito J. 1986. Gibbon systematics. In: Swindler DR, Erwin J, editors. Comparative primate biology, volume 1: systematics, evolution, and anatomy. New York: Alan R. Liss, Inc. p137-85.

Mootnick AR. 2006. Gibbon (Hylobatidae) species identification recommended for rescue or breeding centers. Prim Conserv 21:103-38.

Nettelbeck AR. 1998. Observations on food sharing in wild lar gibbons (Hylobates lar). Folia Primatol 69(6):386-91.

Norhayati A, Saiful AA, Shahrolnizah A, Md-Zain BM, Shukor MN, Hazimin H, Nordin M. 2004. Diversity and density of mammals in the peat swamp forests of the Langat Basin, Selangor, Malaysia. Malays Appl Biol 33(2):7-17.

Nwe DT, San AM, Min NWW, Thu MK, Oi T, Hamada Y. 2005. Species diversity and distribution of primates in Myanmar. Nat Hist J Chulalongkorn U Suppl 1:47-53.

Palombit R. 1994. Dynamic pair bonds in Hylobatids: implications regarding monogamous social systems. Behaviour 128(1-2):65-101.

Palombit RA. 1997. Inter- and intraspecific variation in the diets of sympatric siamang (Hylobates syndactylus) and la ribbons (Hylobates lar). Folia Primatol 68(6):321-37.

Palombit RA. 1993. Lethal territorial aggression in a white-handed gibbon. Am J Primatol 31(4):311-8.

Palombit RA.1992. Pair bonds and monogamy in wild siamang (Hylobates syndactylus) and white-handed gibbon (Hylobates lar) in northern Sumatra. PhD dissertation, University of California-Davis. 453p.

Palombit RA. 1996. The siamang and white-handed gibbon of Gunung Leuser National Park. In: van Schaik C, Supriatna J, editors. Leuser: a Sumatran sanctuary. Jakarta (ID): Yayasan Bina Sains Hayati Indonesia. p269-79.

Raemaekers J. 1979. Ecology of sympatric gibbons. Folia Primatol 31:227-45.

Raemaekers JJ, Raemaekers PM. 1985. Field playback of loud calls to gibbons (Hylobates lar): territorial, sex-specific and species-specific responses. Anim Behav 33(3):481-93.

Raemaekers JJ, Raemaekers PM, Haimoff EH. 1984. Loud calls of the gibbon (Hylobates lar): repertoire, organization and context. Behaviour 91(1-3):146-89.

Raemaekers JJ, Raemaekers PM. 1984b. The ooaa duet of the gibbon (Hylobates lar). Folia Primatol 42(3-4):209-15.

Raemaekers JJ, Raemaekers PM. 1984. Vocal interaction between two male gibbons, Hylobates lar. Nat Hist Bull Siam Soc 32(2):95-106.

Reichard U. 1995. Extra-pair copulations in a monogamous gibbon (Hylobates lar). Ethology 100(2):99-112.

Reichard U, Sommer V. 1994. Grooming site preferences in wild white-handed gibbons (Hylobates lar). Primates 35(3):369-74.

Reichard U, Sommer V. 1997. Group encounters in wild gibbons (Hylobates lar): agonism, affiliation, and the concept of infanticide. Behaviour 134(15-16):1135-74.

Reichard UH, Barelli C. 2008. Life history and reproductive strategies of Khao Yai Hylobates lar: implications for social evolution in apes. Int J Primatol 29(4):823-44.

Reichard U. 1998. Sleeping sites, sleeping places, and presleep behavior of gibbons (Hylobates lar). Am J Primatol 46(1):35-62.

Reichard UH. 2003. Social monogamy in gibbons: the male perspective. In: Reichard UH, Boesch C, editors. Monogamy: mating strategies and partnerships in birds, humans and other mammals. Cambridge(UK):Cambridge U Pr. p190-213.

Roberts R. 1983. The birth and development of a lar or white handed gibbon. Anim Keep Forum 10(12):392-7.

Roonwal ML, Mohnot SM. 1977. Primates of south Asia: ecology, sociobiology, and behavior. Cambridge (MA):Harvard U Pr. 421p.

Savini T, Boesch C, Reichard UH. 2008. Home-range characteristics and the influence of seasonality on female reproduction in white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand. Am J Phys Anthropol 135(1):1-12.

Tangtham N. Khao Yai ecosystem: the hydrological role of Khao Yai National Park. Proceedings of international workshop on conservation and sustainable development, 22-26 April 1991. AIT/Bangkok and Khao Yai National Park, Thailand. p345-63.

Uhde NL, Sommer V. 2002. Antipredatory behavior in gibbons (Hylobates lar, Khao Yai/Thailand). In: Miller LE, editor. Eat or be eaten: predator sensitive foraging among primates. Cambridge (UK):Cambridge U pr. p268-9.

Ungar PS. 1996. Feeding height and niche separation in sympatric Sumatran monkeys and apes. Folia Primatol 67(3):163-8.

Ungar PS. 1995. Fruit preferences of four sympatric primate species at Ketambe, northern Sumatra, Indonesia. Int J Primatol 16(2):221-45.

Vereecke EE, D’Août K, Aerts P. 2006. Locomotor versatility in the white-handed gibbon (Hylobates lar): a spatiotemporal analysis of the bipedal, tripedal, and quadrupedal gaits. J Hum Evol 50(5):552-67.

Weigl R. 2005. Longevity of mammals in captivity; from the living collections of the world. Stuttgart (DE): E. Schweizerbartsche. 214 p.

Whitington CL. 1992. Interactions between lar gibbons and pig-tailed macaques at fruit sources. Am J Primatol 26(1):61-4.

Yimkao P, Srikosamatara S. 2006. Ecology and site-based conservation of the white-handed gibbon (Hylobates lar L.) in human-use forests in Mae Hong Son province, northern Thailand. Nat Hist Bull Siam Soc 54(1):109-38.

Content last modified: November 17, 2010

 

IMAGES

Hylobates lar
Photo: Alan Mootnick
Hylobates lar
Photo: Andrew Johns
Hylobates lar
Photo: Anne Savage
Hylobates lar
Photo: Marilyn Cole
Hylobates lar
Photo: Michael Pogany

Hylobates lar carpenteri
Photo: Alan Mootnick
Hylobates lar carpenteri
Photo: Alan Mootnick

Primate Info Net (PIN) is maintained by the Wisconsin National Primate Research Center (WNPRC) at the University of Wisconsin-Madison, with countless grants and contributions from others over time. PIN is an ever-growing community effort: if you’d like to contribute, or have questions, please don’t hesitate to contact us.