In Sumatra, there are apes who sing!
Have you heard of apes that sing? Probably not. But they do exist. The siamang apes of Sumatra Island, Indonesia, are famous for singing and swinging. Surprisingly, they have a pinkish or greyish neck sac which expands during vocalisations and can grow to a grapefruit size. These apes also swing like a pendulum, grabbing one branch and releasing it before catching the next. How big are they? Siamangs range in height from 29 to 30 inches and weigh around 10 kg. Both males and females have black furry bodies, no tails, and their second and third toes are webbed. ant to know more about these special apes? Keep reading.
These apes communicate through singing
Vocalisation is a significant social commitment for siamangs! They sing through their neck sac with lips closed. This produces a resounding ‘boom’. When they sing with their mouth open, a loud ‘wow’ sound is produced.
Trying to figure out which sound can travel more distance? In forests, a deep boom sound travels further than a high-pitched wow. The deep booming calls of siamangs are one of the loudest natural calls in the rainforests of Sumatra and Malasia travelling up to three kilometres. They often engage in behavioural gymnastics, where they repeat their calls one at a time. They begin slowly and pick up speed over time.
Siamangs even perform duets. Males and females pair up with one another. Each pair comes up with a unique tune of its own!
Swinging like a pro!
If you want to spot a siamang in its native tropical forest in Malaysia and Indonesia? Check out the leaves and look at the sky. You will find them 80 to 100 feet up in the trees! Siamangs are the kings and queens of swinging. This is because of their lean bodies and light bones, which allow for some significant swing. Swinging is the primary method of movement for the siamangs because their arms are longer than the legs. The movement of their arms resembles the left-to-right motion of walking legs. Siamangs swing their bodies to allow the other hand to grab the next branch while hanging by one hand.
Siamangs follow a daily schedule
Just like us, they have a daily routine too. They conduct their morning calls as soon as they awaken at daylight. Then, they search for food. How do they do this? A family’s adult female typically begins a territorial hoot first thing in the morning. The others follow suit. This loud signal to neighbouring siamang families can last up to 30 minutes.
Siamangs are distinguishable because they have close communication and coordination during regular tasks. Typically, the family goes hunting together for food which mainly fruits and new leaves. These apes often finish their meals in five hours or less and they need rest after eating as well! After eight to ten hours of work, they find a place to rest or sleep.
Siamangs are ferociously territorial and perform daily singing rituals to protect their lands. Boundary disputes are rare. But when they do happen, it involves chasing through the woods with slapping and even biting the intruder!