Understanding whether the long and elaborate songs of male gibbons have syntax and hierarchical structures is an interesting question in the evolution of language, because gibbons are near humans in the phylogenetic tree and a hierarchically organized syntax is considered to be a basic component of human language. We conducted field research at Danum Valley Conservation Area in northern Borneo to test the hypothesis that gibbon songs have syntax and chunks. We followed one Mueller’s gibbon group for 1 week in (...) the dry and rainy seasons every year from 2001 to 2009, collecting vocal and behavioral data. Results show that songs emitted by the studied male gibbon were governed by combinatory rules. Some context-dependent songs had different combinatory rules, although they overlapped with the songs whose contexts were uncertain. The male Mueller’s songs had characteristics that suggest existence of chunk structure. These results provided an important perspective in the study of language origin. (shrink)

Mueller's gibbons ( Hylobates muelleri ) sing both sex-specific and duet songs. These songs are thought to be involved in territory maintenance, as well as the maintenance of pair or family bonds. However, few observational studies have examined how gibbons interact with their neighbors through song in the wild. We have been conducting field observations of wild gibbon groups in northeast Borneo since 2001. In the Borneo Rainforest Lodge (BRL) and Danum Valley Field Center (DVFC) at the Danum Valley Conservation (...) Area (DVCA), we observed seven episodes of alternating songs between males. Here, we describe the process of song exchange between males. During male interactions, song bouts rarely overlapped and were alternately emitted. Several studies have reported antiphonal vocalizations in New World and Old World primate species, but rarely in apes. Our observations of antiphonal songs in gibbons indicate that gibbons not only unilaterally advertise information, but also interactively communicate with neighbors and family members through songs. Since gibbons are phylogenetically similar to humans, and turn-taking has an important role in human conversation, our research on gibbon communication may provide insight into the evolution of human language. (shrink)

Mueller’s gibbons sing both sex-specific and duet songs. These songs are thought to be involved in territory maintenance, as well as the maintenance of pair or family bonds. However, few observational studies have examined how gibbons interact with their neighbors through song in the wild. We have been conducting field observations of wild gibbon groups in northeast Borneo since 2001. In the Borneo Rainforest Lodge and Danum Valley Field Center at the Danum Valley Conservation Area, we observed seven episodes of (...) alternating songs between males. Here, we describe the process of song exchange between males. During male interactions, song bouts rarely overlapped and were alternately emitted. Several studies have reported antiphonal vocalizations in New World and Old World primate species, but rarely in apes. Our observations of antiphonal songs in gibbons indicate that gibbons not only unilaterally advertise information, but also interactively communicate with neighbors and family members through songs. Since gibbons are phylogenetically similar to humans, and turn-taking has an important role in human conversation, our research on gibbon communication may provide insight into the evolution of human language. (shrink)