International Gibbon Day 2024
Photo: Mrozowski Marie-Laure at WFFT Thailand
Today, we celebrate International Gibbon Day: a day dedicated to honouring these incredible and often overlooked primates. Known for their acrobatic abilities and their playful nature, gibbons are a vital part of the world's biodiversity. Let's explore the fascinating world of gibbons and learn about the importance of protecting their future.
Most people know the “Great Apes” or Hominidae: gorillas, bonobos, chimpanzees, orangutans, and humans. Gibbons, however, are often referred to as 'Lesser Apes,' a designation that has drawn criticism from primatologists. This outdated (and slightly derogatory) nickname was given to gibbons due to their smaller body size, but also because of their perceived lower intelligence compared to their great ape counterparts.
Recent studies, however, challenge this notion. Gibbons have been observed to exhibit complex behaviours, including tool use, problem-solving, and intricate social structures, comparable to their great ape relatives. Consequently, the more accurate term 'smaller apes' is gaining traction. Moreover, genetic studies show that gibbons and great apes share a common ancestor (Gibbons, 1998; Grabowski and Jungers, 2017). They now are divided into four genera, comprising around 20 species which are spread across 11 countries in Asia.
While sharing many similarities with great apes, gibbons exhibit distinct characteristics. Unlike their larger cousins, gibbons do not construct nests and display less sexual dimorphism, meaning there are fewer physical differences between males and females (with certain exceptions). Both gibbons and great apes are tailless and generally larger than monkeys, often spending more time on the ground than their more arboreal monkey counterparts.
Gibbons, scientifically known as Hylobatidae (Greek for "tree or forest walkers"), are highly adapted to their lifestyle high up in the trees, or canopy layer, of the rainforests. Their unique mode of locomotion, brachiation, enables them to swing through the trees at astonishing speeds of up to 55 km/h.
Photo: Hamish Pritchard for BBC News
These apes usually travel in small family groups of up to five individuals. That is because this species is largely monogamous, forming unique pair bonds for life. As gibbons are excellent singers, these pairs perform unique harmonious vocalisations, or “duets”, to strengthen their partnership, and announce their territoriality. Gibbons typically give birth to a single offspring at a time, carrying their young on their abdomen for approximately 6 to 7 months.
You can hear them singing here: https://www.youtube.com/watch?v=JLOn8F0p96s
Most species in the Hylobatidae family are Critically Endangered, Endangered, or Vulnerable according to the IUCN Red List, showing a decrease in population size. This highlights the urgent threat these apes face in the wild. The primary reasons for their threatened status are habitat loss due to deforestation, and the illegal pet trade. The latter is particularly harmful, as gibbons are captured from the wild and often subjected to cruel conditions during transportation and captivity. They are frequently used as photo props as tourists attractions as well.
Despite these challenges, there are ongoing conservation efforts to protect gibbons and their habitats.By celebrating the International Day of the Gibbon, we raise awareness about the plight of these incredible creatures and highlight the importance of conservation efforts to protect their future. Through collective action, we can ensure that gibbons continue to swing through the trees for generations to come.
If you want to learn more about gibbons and what you can do for these enchanting singing apes, here are some links to organisations involved in their conservation:
https://www.gibbonproject.org/ - The Gibbon Rehabilitation Project in Thailand
https://www.wfft.org/ - Wildlife Friends Foundation Thailand
https://primatesmalaysia.org/home/ungka-gibbons-of-peninsular-malaysia-project/ - UNGKA gibbons of Peninsular Malaysia
https://ippl.org/ippls-gibbon-sanctuary/ - International Primate Protection League
https://gibbons.asia/ - IUCN Section on Small Apes
References:
Cheyne, S.M. (2009) 'Studying Social Development and Cognitive Abilities in Gibbons (Hylobates spp): Methods and Applications,' Primatology: Theories, Methods, and Research [Preprint].
Cheyne, S.M. (2010) 'Gibbon Locomotion Research in the field: Problems, possibilities, and Benefits for conservation,' in Springer eBooks, pp. 201–213. https://doi.org/10.1007/978-1-4419-1420-0_11.
Clarke, E., Reichard, U.H. and Zuberbühler, K. (2006) 'The syntax and meaning of wild Gibbon songs,' PLoS ONE, 1(1), p. e73. https://doi.org/10.1371/journal.pone.0000073.
Geissman, T. (2002) 'Taxonomy and Evolution of Gibbons,' Evolutionary Anthropology: Issues, News, and Reviews, pp. 28–31. http://www.gibbons.de/main/papers/pdf_files/2002taxonomy&evolution.pdf.
Gibbons, A. (1998) 'New study points to Eurasian ape as great ape ancestor,' Science, 281(5377), pp. 622–623. https://doi.org/10.1126/science.281.5377.622.
Grabowski, M. and Jungers, W.L. (2017) 'Evidence of a chimpanzee-sized ancestor of humans but a gibbon-sized ancestor of apes,' Nature Communications, 8(1). https://doi.org/10.1038/s41467-017-00997-4.
Marshall, J.T. and Marshall, E.R. (1976) 'Gibbons and their territorial songs,' Science, 193(4249), pp. 235–237. https://doi.org/10.1126/science.193.4249.235.
