Siamang

The siamang (Symphalangus syndactylus) is a species of gibbon only in Malaysia, Thailand and Sumatra.  It is one of the largest gibbons and has a large throat sac which it uses to make loud calls.  It is currently protected by law.


Physical Features
Siamangs are the largest of the the gibbons, measuring 90 cm (35 inches) and weighing 13 kilograms.  Both males and females have large throat sacs.  It can sometimes be twice the size of other gibbons.  Siamangs have a height of 3.3 feet ( 1 meter).  Their throats sacs are called gular sacs.  They have two digits on each foot which are partially joined with a membrane.  They can inflate their throat sacs to the size of their heads.  They have black fur and have a very long hand which is shaped like a hook at the end.  They have a life span of 30 years.


Diet
Siamangs spend about 5 hours in a day eating.  They are omnivores, eating insects, fruits, invertebrates and leaves.  Half of their diet is made up of leaves.  Siamangs always hang on a tree with one hand while feeding.  They feed on about 160 species of plants.


Behavior
Siamangs spend 50 % of their time in resting.  Siamang pairs may start their first day with a duet led by the female and with the male giving melody support.  This singing (which is like shrieking in different tunes) even acts like a territorial display.  Siamangs can give loud and deafening shrieking calls with their large throat sac.


Distribution and Habitat
Siamangs are found in the rainforests of Malaysia, Thailand and Sumatra


Population and Threats
In 1990, there was an estimated population of 360,500 individuals in the wild found in Indonesia.  In Sumatra's (Indonesia) third national park, Bukit Barisan Selatan National Park, the population was 22,390 individuals according to 2002.  Even though hunting hunting primates for meat in Indonesia is banned (unlike other part of Asia) they are threatened due to forest fires and illegal logging.  In Malaysia and Thailand, infants are taken for illegal pet trade.  Their mothers are killed as they are highly protective of their young and will be very difficult to separate the infants and their mother.


Source of picture 1:http://en.wikipedia.org/wiki/Siamang_Gibbon#Siamang_and_their_habitat