Free Research Paper About Gibbons Vs. Siamangs

Introduction

The gibbon is a tailless ape in the family Hylobatidae. Today there are four genera in this family, previously from one genus. Gibbons can be found in tropical and subtropical rainforests. Today, one can locate these apes in eastern Bangladesh and northeastern India, as well as in southern China and in Sumatra, Borneo, Java and other parts of Indonesia. Gibbons are classified also as the lesser apes, as opposed to the greater apes (chimpanzees, gorillas and orangutans) as they are said to be smaller and have low sexual dimorphism (phenotype differences between the sexes). The main mode of locomotion of these animals is brachiation, or the swinging from branch to branch at speeds as high as 55 kph. Gibbons may be colored differently, from dark to white, although it is very rare to see a totally white animal (Springer and Holly, 2012, 486). Sadly, as mentioned in the website of A-Z Animals, most species of this ape are classified as endangered species due to the loss of their forest habitats.

The Gibbon

Physically, in general, the gibbon is a small and lightweight monkey that grows to about 90 cm in height, although there are those that grow up to a meter in height. The average weight of a gibbon is about 7 kgs. This lightweight feature enables the gibbons to swing swiftly from tree to tree in their natural habitat. In addition to this, gibbons have exceptionally long arms, oftentimes longer than their legs. These arms are used for swinging from tree to tree in their arboreal habitats. There have been instances wherein they can swing 15 meters from one tree to another. They also can leap long distances of up to 8 meters. They are also omnivorous animals, eating a great mixture of plants and animals. Their main food is fruit that they take from the trees, and they also consume insects, egg, spiders and small reptiles. However, they also have their predators. Among their main predators are the leopards, larger snakes and birds of prey. Their life span is from about 25 to 40 years (Rosenblum, 2012, 252-255).

The Siamang

The siamang is actually the lone species in the genus Symphalangus. It is therefore strictly a gibbon. It also does not have a tail, and is the biggest of the gibbon family. Scientists have also recommended that there be two new subspecies of siamangs: the Sumatran siamang and the Malaysian siamang. Siamangs are found mainly in the remaining arboreal areas of Sumatra and in the Malay Peninsula, and is distributed from the lowlands to the higher altitude forests of these areas. The siamang lives in groups of up to six individual animals with an average home range of 23 hectares. It is also said that the siamang “sings” in a very melodious voice; its singing can be heard in the forest. It also consumes a diet of mostly fruits, and prefers to eat ripe rather than unripe fruit.

Anatomical and Behavioral Differences between the Gibbon and the Siamang

The anatomical differences between the Gibbon and the Siamang can be seen below:
All gibbons (siamangs included) have all the features mentioned earlier. However, anatomically, the main differences between the larger gibbon group and the specific group of the siamangs can be seen in the second green circle. In the website of the University of Wisconsin-Madison, it is mentioned that Siamangs are darker haired (often black), have shaggier-looking hair, are bigger – they can grow up to a meter and 50 centimeters in height and have more fruit in their diet. The two biggest physical differences could be said to be the presence of the membrane joining two digits on each foot of the siamangs, and the large gular sacs found on their neck areas as well. The large gular sac is present in both males and females of the siamangs.
Behaviorally, one could also say that the siamangs are greater agents of seed dispersion through defecation, as they consume more fruit than the other gibbons in the group. Also, as they are large fruit-consumers, their mating periods are dependent on the fruit season, meaning copulation normally occurs when ripe fruit is in abundance. What is also unique to the siamang is that it rests for about half of its waking period, which is usually from sunrise to sunset (Lappan, 2008, 1307-1317). Unfortunately, as with the case of the gibbons in general, per the website of the IUCN, the existence of the siamang is challenged today due to a loss of habitats. For instance, in Sumatra, the clearing of the arboreal habitats of siamangs is being done to give way to create new palm date plantations due to the increasing demand of palm oil from around the world today. Measures have been taken by conservation groups in order to preserve the habitat of these unique animals.

Works Cited

A-Z Animals. Gibbon. 2015. Web. http://a-z-animals.com/animals/gibbon/ 21 March 2015.
IUCN. The IUCN Red List of Threatened Species. 2014. Web. http://www.iucnredlist.org/news/nearly-one-in-ten-wild-bee-species-face-extinction-in-europe-while-the-status-of-more-than-half-remains-unknown-iucn-report 21 March 2015.
Lappan, Susan. “Male Care of Infants in a Siamang Population Including Socially Monogamous and Polyandrous Groups”. 2008. Behavioral Ecology and Sociobiology, 62(8): 1307-1317.
Rosenblum, Leonard. Primate Behavior. London: Academic Press. 2012.
Springer, Joseph and Holley, Dennis. An Introduction to Zoology. NY: Jones and Bartlett Publishers. 2012.