Camera trap shows Sumatra orangutan using a canopy bridge to cross a road in Indonesia

A Sumatran orangutan has been captured on film using a human-made canopy bridge to cross a public road on the Indonesian island of Sumatra for the first time, conservationists announced Monday.

The footage, recorded by a motion-sensitive camera, shows a young orangutan pausing at the edge of the forest and carefully gripping a rope before stepping into the open air. The animal stopped halfway across to look at the road below before completing the crossing.

Combating Habitat Fragmentation

The bridge spans the Lagan – Pagindar Road in the Pakpak Bharat district. This road serves as a vital corridor for local villages but cuts directly through prime habitat, splitting an estimated 350 orangutans into two isolated forest areas.

When the road was upgraded in 2024, the gap in the forest canopy widened. This change eliminated natural crossings for tree-dwelling wildlife, effectively trapping orangutans on either side of the pavement.

“Development was necessary for people,” said Erwin Alamsyah Siregar, executive director of the Indonesian conservation group Tangguh Hutan Khatulistiwa, or TaHuKah. “But without intervention, it would have left orangutans trapped on either side.”

Engineering a Wildlife Solution

TaHuKah, in collaboration with the Sumatran Orangutan Society (SOS) and government agencies, installed five rope bridges suspended between trees. These structures were specifically designed to support the weight of the world’s largest tree-dwelling mammal.

Conservationists waited two years for an orangutan to use the bridges. During that time, camera traps recorded squirrels, langur monkeys, macaques, and gibbons utilizing the crossings.

Siregar noted that orangutans are cautious observers who do not rush. They typically build nests near the bridge and test the ropes repeatedly before deciding it is safe to move.

Preventing Population Collapse

While similar bridges have been used over rivers or private industrial roads, conservationists state that noisy and unpredictable public roads pose a much greater challenge for the species.

Restoring connectivity is vital to prevent inbreeding and genetic weakening, which can lead to population collapse. The bridges allow the animals to mix and maintain healthy populations, reducing the overall risk of extinction.

Sumatran orangutans now survive only on the islands of Sumatra and Borneo. According to conservation groups, there are fewer than 14,000 Sumatran orangutans, approximately 800 Tapanuli orangutans, and roughly 104,700 Bornean orangutans remaining in the wild.