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

Rapid development has been shrinking the jungle habitat of the critically endangered species, and fatal conflicts with people have been increasing.

The fleeting scene, captured by a motion‑sensitive camera, showed a young Sumatran orangutan pause at the forest's edge, grip a rope with deliberate care and step out into open air. Halfway across, it stopped, casting a glance down at the road below.

"Then, with a cheeky glance to camera, he continues on his way," the Sumatran Orangutan Society, or SOS, said in a social media post showing the video.

Conservationists said that it marks the first documented case of a species on the brink of extinction using an artificial canopy bridge to cross a public road that had divided its habitat.

"This was the moment we had been waiting for," Erwin Alamsyah Siregar, executive director of Indonesian conservation group Tangguh Hutan Khatulistiwa, or TaHuKah, told The Associated Press. "We are very grateful that the canopy here provides benefits for orangutan conservation efforts."

He said that the bridge spans the Lagan-Pagindar road in Pakpak Bharat district, a vital corridor connecting remote villages to schools, healthcare and government services. But the road also cuts directly through a prime orangutan habitat, splitting an estimated 350 orangutans into two isolated forest areas: the Siranggas Wildlife Reserve and the Sikulaping Protection Forest.

When the road was upgraded in 2024, the gap in the forest canopy widened, eliminating natural crossings for tree‑dwelling wildlife.

"Development was necessary for people," Siregar said. "But without intervention, it would have left orangutans trapped on either side."

TaHuKah, working with SOS and local and national government agencies, proposed a simple solution: rope bridges suspended between trees, allowing arboreal animals to cross above traffic.

While other species including gibbons and long-tailed macaques have also been spotted crossing there, "this is a world first for Sumatran orangutans," SOS told AFP.

"One orangutan has crossed, but a population of 350 still remains isolated," SOS said in a statement on social media.

Five canopy bridges were installed, each with a camera trap, carefully positioned after surveys of orangutan nests, forest cover and animal movement. The structures were designed to support the orangutan's weight — no small feat for the world's largest tree‑dwelling mammal.

The program is closely monitored, with camera traps on every bridge and regular patrols to prevent forest encroachment. Conservationists hope more orangutans will follow the first pioneer.

"Seeing this young male orangutan confidently cross the road is a huge milestone for conservation — proving that it is possible to stitch fragmented forests back together," SOS said on social media.

They waited two years for the first orangutan to cross the bridge. Before the accomplishment, only smaller animals used it. Camera traps recorded squirrels, langur monkeys and macaques, followed by gibbons — a promising sign.

The orangutan's approach was slower, building nests near the bridge, lingering at its edges and testing the ropes over time.

"They observe," Siregar said. "They don't rush. They watch, they try, they retreat. Only when they're certain it's safe do they move."

Then, one day, he crossed fully — a first not just for Sumatra, but for the species globally on a public road, conservationists say.

Similar bridges have been used by orangutans elsewhere, but usually over rivers or on private industrial forest roads. Conservationists say public roads — noisy, busy and unpredictable — pose a far greater challenge.

For orangutans, the stakes are high. Isolation leads to inbreeding, genetic weakening and eventual population collapse. Restoring connectivity gives them a chance to survive.

Once widespread across southern Asia, the animal now only survives on the islands of Sumatra and Borneo. Fewer than 14,000 Sumatran orangutans remain in the wild, alongside just 800 Tapanuli orangutans and about 104,700 Bornean orangutans, according to conservation groups.

"These bridges allow orangutans to move, to mix, to maintain healthy populations," Siregar said. "It reduces the risk of extinction."