By Liat Clark, Wired UK
Regional accents have been discovered in the songs of crested gibbons, our closest relatives after great apes.
The small apes (genus Nomascus) -- found in Vietnam, Laos, Cambodia and southern China -- were already known to communicate in species-specific song when defining territory or attracting mates. However, researchers from the German Primate Centre in Göttingen have discovered conclusive correlations between song structure, genetics and geography, answering questions surrounding the primates' evolutionary development and migration patterns in the process.
Evolutionary biologist Van Ngoc Thinh explained in a press release: "Each gibbon has its own variable song but, much like people, there is a regional similarity between gibbons within the same location."
The study, published yesterday in the BMC Evolutionary Biology journal, focused on the song structure of six crested-gibbon species, paying particular attention to the four most closely related. More than 400 male and female songs were recorded from 92 groups, in 24 different locations.
"The structure of gibbon songs shows a clear adaptation to improved long-distance transmission," the study states, meaning they have adapted to their natural habitats in forests across Asia. Songs are emitted in single-frequency bands with slow modulation, producing a sound more akin to that of rain-forest birds than to other primates.
Though there are similarities in species' song structures, there are many variations -- as with individual voices. By comparing analysis of 53 different vocal features with species' genetics, it was found that four of the most similar songs came from species with the most closely related DNA and the closest proximity to one another. It was also discovered that gibbons from the southernmost regions were more closely related than those in northern Vietnam and China, indicating the primates originated in the north and popular migration is to the south.
It was concluded that songs and calls of other primate species are likely to proffer similar results, therefore these findings can be more widely used to help researchers identify genetic relationships between species and define migration history.
Image: Black-crested gibbon./Flickr/Stephen Desroches.
Source: Wired.co.uk.
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