Siamang sitting on a fallen tree with a stick in its mouth


King of swing
giant panda


Map of Asian countries
Endangered Status



~33 inches
from head to rump
Illustration of a swinging siamang and a soccer ball
plants & more
Illustration of leaves, an insect, and meat

About half of what a siamang eats is fruit. The rest is mostly leaves. Sometimes siamangs eat small birds or their eggs, spiders, and insects. 

Illustrations of tropical leaves


One adult siamang sitting on a rope and one juvenile siamang swinging from a rope


Ape or monkey?

Siamangs are at home in the trees, but they aren’t monkeys—they’re apes! How can you tell? Apes never have tails; almost all monkeys do. Siamangs are smaller than great apes (gorillas, orangutans, chimps, and bonobos), so they are sometimes called “lesser” apes.

A siamang swinging on a rope


A siamang’s arms are longer than its legs. It travels by swinging through the trees. Hanging from a branch by one hand, it swings its body forward to grab the next handhold. Have you ever tried doing this on a playground? A siamang’s extra-long arms help it travel up to 10 feet in a single swing.

An adult and baby siamang laying in tall grass

All in the family

A typical siamang family includes mom, dad, and two or three youngsters. Soon after it’s born, a baby can hold onto its mother’s fur and cling to her belly. Siamang fathers help, too. After a baby’s first birthday, dads pretty much take over their care. Siamangs older than about seven go off on their own to find a mate.

A siamang sitting on a perch with its throat sac inflated

Siamang songs

First thing in the morning, a siamang family starts a territorial hooting that can last 30 minutes. The noisy warning to other siamang families can be heard up to two miles away. Paired males and females also sing to one another. The longer they are together, the more their duet changes.


Is a siamang a monkey or an ape?