SIAMANG

Phylum — Chordata
Class — Mammalia
Order — Primates
Family — Hylobatidae
Genus — Symphalangus
Species — Symphalangus syndactylus

The natural range of the species includes the foothills and the Barisan mountain range on the island of Sumatra (Indonesia), the mountains of the Malay Peninsula (Malaysia), and a small area in the north of the Malay Peninsula (Thailand). Siamangs inhabit tropical evergreen and deciduous forests and are rarely found in swampy areas.

In 2015, paleontological remains (a tooth) belonging to a previously unknown extinct species of primates from the gibbon family were discovered in northern India. The species was named Kapi ramnagarensis. It lived approximately 12.5–13.8 million years ago (Middle Miocene epoch) and differed from all other fossil apes known at that time. This discovery makes it possible to trace the migration route of primates (in particular, the ancestors of gibbons and orangutans) from Africa to Southeast Asia. Today, this species is considered the ancestor of modern gibbons and siamangs.

Siamangs are the largest members of the gibbon family, with adult body weight ranging from 10 to 12 kg. Despite their relatively small body length (70–90 cm), the span of their long forelimbs can reach up to 1.5 meters. This anatomical feature allows siamangs to move skillfully through the tree canopy, which looks like flying from branch to branch. Holding on with one hand, they swing their bodies and leap to the next branch, grasping it with the other hand. A single “leap” can reach 10–12 meters. This mode of locomotion is called brachiation. Siamangs live almost exclusively in trees and rarely descend to the ground. They are territorial animals and defend their own areas, which may range from 20 to 50 hectares.

These apes have dense black fur and lack tails. Another characteristic feature of siamangs is syndactyly—the presence of connective tissue linking the second and third fingers. This trait is reflected in the species name syndactylus (from Ancient Greek syn — “together” and daktulos — “finger”). In addition, these primates have a well-developed throat sac that serves as a powerful resonator during singing. Thanks to this adaptation, siamang calls can be heard at distances of 3–4 kilometers. Their songs help mark territory and enable communication between individuals. The throat sac in both males and females is always hairless.

Siamangs form monogamous pairs and live in family groups. Females give birth to one, very rarely two infants. Gestation lasts about seven months. The mother cares for the infant for up to two years; during the first three to four months of life, the infant constantly clings to the mother’s belly. Other family members may also help care for the young. Juveniles leave the family at the age of 6–7 years. Lifespan in the wild is 10–20 years, while in captivity they can live significantly longer. Their diet consists mainly of fruits and plant material; occasionally they may consume insects and bird eggs. They are active during the day, and at night they sleep sitting on branches, without building nests or shelters.

What are the main threats to siamangs?

• loss and fragmentation of habitats due to logging, infrastructure development, and agriculture;

• poaching for illegal trade.

The conservation status of the species in the IUCN Red List of Threatened Species™ is Endangered (EN). It is protected under Appendix I of the CITES Convention (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and by national laws of Indonesia, Malaysia, and Thailand.

Residents of the Kyiv Zoo

The first thing visitors see when entering through the new central entrance is a unique arched structure of one of the largest siamang enclosures in the world.

These apes are among our closest “relatives” in the animal kingdom, and they now live in conditions as close to natural as possible. An important feature of this enclosure is the presence of large living trees inside. By the way, the favorite tree of our siamangs is the cherry tree.

Currently, the family consists of Patrick, Tisa, and their two-year-old offspring Teddy. In such a large enclosure (over 20 meters long), siamangs can fully demonstrate their acrobatic skills and their unique mode of locomotion—brachiation.

In the morning, just as the zoo opens, siamang songs resonate throughout the area. These songs are truly mesmerizing! Each siamang family has unique vocalizations that allow them to mark their territory.

The family’s diet consists of foods that are as close as possible to those consumed by siamangs in the wild. Throughout the year, our monkeys enjoy fresh vegetables and fruits, nuts, dried fruit compote (uzvar), and dried fruits. Their favorite treat is zophobas larvae (larvae of darkling beetles).