Calling in wild silvery gibbons (Hylobates moloch) in Java (Indonesia): behavior, phylogeny, and conservation

  title={Calling in wild silvery gibbons (Hylobates moloch) in Java (Indonesia): behavior, phylogeny, and conservation},
  author={Thomas Geissmann and Vincent Nijman},
  journal={American Journal of Primatology},
Hardly any behavioral data are available for the silvery gibbon (Hylobates moloch), an endangered primate that is endemic to the island of Java, Indonesia. We studied the singing behavior of the easternmost population of this species in the Dieng mountains, central Java, in 1998–1999. We aimed to document the timing of singing, quantify the amount of singing by the respective sexes, and explore the role of bioacoustics in density estimation. A total of 122 song bouts in at least 12 groups were… 
Individual and Geographical Variability in the Songs of Wild Silvery Gibbons (Hylobates Moloch) on Java, Indonesia
The aim of this study is to answer the following questions: to what degree is great-call variability within a species useful for both individual and population identification and to test the validity of subspecific taxon boundaries suggested by previously reported genetic data.
Singing Patterns of White-Cheeked Gibbons (Nomascus sp.) in the Annamite Mountains of Laos
Songs of white-cheeked gibbons (Nomascus sp.) are recorded from listening posts at a site in Nakai–Nam Theun National Protected Area, central-eastern Laos, during a cold dry and a warm dry season, and a significant negative relationship between the number of song bouts heard and temperature is found.
Singing by male and female Kloss gibbons (Hylobates klossii) in the Peleonan Forest, Siberut Island, Indonesia
This study supports the hypothesis that male and female songs function in intrasexual resource defence, as singing is associated with singing bySame-sex neighbours, and same-sex choruses are more likely to occur after one or more days of silence (from that sex), suggesting there is pressure for individuals to communicate with same- sex neighbours regularly.
Javan gibbon (Hylobates moloch) is one of endemic primates in Java Island, which listed as endangered and facing the high risk of extinction. Conservation efforts need to be taken immediately in
Geographic variation in loud calls of sportive lemurs (Lepilemur ssp.) and their implications for conservation
It is revealed that loud calls separated geographically isolated populations of sportive lemurs specifically, and noninvasive tools for diagnosis and monitoring of cryptic species in nature can be developed for conservation management.
Female Songs of the Nonduetting Javan Gibbons (Hylobates moloch) Function for Territorial Defense
Duets in territorial, pair-living primates may function to maintain intragroup cohesion, promote intergroup avoidance, and assist in territorial and resource defense, as well as advertising and
Diet and ranging behavior of the endangered Javan gibbon (Hylobates moloch) in a submontane tropical rainforest
The results suggest that Javan gibbons in higher elevation habitats have substantially larger home ranges than lowland populations, despite broad similarity in their activity budgets and diets.
Calling patterns of Western purple-faced langurs (Mammalia: Primates: Cercopithecidea: Trachypithecus vetulus nestor) in a degraded human landscape in Sri Lanka
Results show that vocalisations can be used to distinguish individual males; as langurs are more often heard than seen, and most troops contain only a single adult male, vocalisations may beused to determine the number of troops in an area.
Kloss gibbon (Hylobates klossii) behavior facilitates the avoidance of human predation in the Peleonan forest, Siberut Island, Indonesia
It is argued that behaviors that may reduce the risk of predation by humans during singing (the most conspicuous gibbon behavior), daily non‐singing activities and encounters with humans, and a coordinated response to the presence of humans are an evolved response to a long history of predations by humans.
Concordance between vocal and genetic diversity in crested gibbons
The results show that the structure of crested gibbon songs is not only a reliable tool to verify phylogenetic relatedness, but also to unravel geographic origins as vocal production in other nonhuman primate species appears to be evolutionarily based.


Individuality in the female songs of wild Silvery Gibbons (Hylobates moloch) on Java, Indonesia
The results do not support the hypothesis that H. moloch females compensate for the rarity of male song contributions with an elevated degree of individuality in their singing, and it is suggested that the amount of great call individuality may be compromised by the amounts of a trill component exhibited by various species of the lar group of gibbons.
The ecology of singing in Kloss gibbons (Hylobates klossii) on Siberut Island, Indonesia
  • A. Whitten
  • Environmental Science
    International Journal of Primatology
  • 2007
Data are presented from a study of habituated Kloss gibbons on Siberut Island, Indonesia. Male Kloss gibbons can sing at any time from 0100 to 1300 hr, but the majority of songs is concentrated in
The male song of the Javan silvery gibbon (Hylobates moloch)
As a surprising finding of the study, male phrase variability both within and between individuals appears to be higher in H. moloch than in most, perhaps all, other gibbon species.
Conservation of the Javan gibbon Hylobates moloch: population estimates, local extinctions, and conservation priorities
The Javan gibbon is one of the rarest species of gibbons, restricted as it is to the western half of the densely populated island of Java, Indonesia. Based on a study from 1994-2002 it was found that
Songs, choruses and countersinging of Kloss' gibbons (Hylobates klossii) in Siberut Island, Indonesia.
  • R. Tenaza
  • Psychology
    Zeitschrift fur Tierpsychologie
  • 1976
Song is mainly for interterritorial communication between members of the same sex, male-song probably also functions in mate attraction, and chorusing is primarily an adaptation reducing predation risk to singing gibbons.
The organization of song in Müller’s Gibbon (Hylobates muelleri)
The adult pairs were found to produce loud, complex, interactive, and sequentially organized duet bouts, which were dominated by the females, and the adult males produced long and elaborate solo bouts,which were neither sequentially nor interactively organized.
Loud Calls of the Gibbon (Hylobates Lar): Repertoire, Organisation and Context
We describe and illustrate with sonograms the loud calls of a monogamous, territorial ape, the lar gibbon (Hylobates lar). We attempt an overview of its repertoire of loud calls, their organisation,
Duet‐splitting and the evolution of gibbon songs
  • T. Geissmann
  • Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2002
This appears to be the first time that a non‐duetting animal can be shown to be derived from a duetting form, and the return to exclusive solo singing may be related to the isolated island distribution of the non-duetting species.
Estimation of density of gibbon groups by use of loud songs
The density of gibbon populations may be estimated by listening for the loud duetted songs of monogamous territorial groups. This method requires a correction factor which must be estimated from the
A faunal survey of the Dieng Mountains, Central Java, Indonesia: distribution and conservation of endemic primate taxa
A faunal survey was conducted in May–September 1994 and June–July 1995 in the Dieng Mountains, one of the last remaining larger patches of forest in CentralJava province, Indonesia. All three primate