‘Cries of delight’ as Sumatran orangutan filmed using canopy bridge to cross road for first time | Endangered species
The endangered Sumatran orangutan has been spotted using a shaded bridge to cross a road for the first time.
In 2024, conservationists in the Pakpak Bharat region of Indonesia’s North Sumatra built a high bridge over the Lagan-Pagindar road, which provided an important route for local people but became a barrier for animals.
Erwin Alamsyah Siregar, director of environmental organization Tangguh Hutan Khatulistiwa (TaHuKah), which helped build the bridge, said the natural crossing was “impossible for wildlife.”
For two years, Sumatran Orangutan Society (SOS) and his local partner, TaHuKah, were watching camera trap footage of the bridge, waiting for the day an orangutan would finally cross.
“You should have heard the cheers from the team,” said SOS CEO Helen Buckland. “After two long years, it finally happened.”
This is the first time the species has been caught on camera crossing a wildlife bridge, offering a glimmer of hope to conservationists who worry that this population would become functionally extinct if isolated in one section of forest.
The road spelled disaster for the area’s 350 orangutans; because he divided them into two populations, one in Siranggas wildlife reserve and the other in Sikulaping reserve forest.
“Orangutans have a very slow life history and are really prone to genetic bottlenecks,” Buckland said. If kept in small groups, they will be weakened through inbreeding until they become functionally extinct: although they may survive for now, they are headed for extinction in the long term.
After building the bridge with help from the local government, several different species began using it: giant black squirrels, long-tailed macaques, agile gibbons but no orangutans.
The young male orangutan is seen heading towards the bridge before crossing the street. Halfway through, he stops to look at the road below, then looks back at the camera before heading towards the Sikulaping reserve forest.
Orangutans, the largest arboreal (arboreal) mammal, are a keystone species and spend more than 90% of their time in the forest canopy. They have excellent memories and can create mental maps of new routes in forest habitats.
There are three species of orangutan in total, and the entire wild population is concentrated in this corner of Southeast Asia. There is just 14,000 Sumatran orangutans leftThis makes them one of the most threatened monkeys in the world.
Pakpak Bharat region president Franc Bernhard Tumanggor said: “Witnessing a Sumatran orangutan safely cross this bridge is living proof that we do not need to cut the lifeline of the forest to build our own communities. Modernization does not mean destruction.”
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