KINABATANGAN: One orang utan has been seen using the rope bridge built specifically to reconnect isolated orang utan populations in the Kinabatangan Wildlife Sanctuary to cross the Rasang river and get to another part of the sanctuary.

Snapshots taken in February show a young male primate crossing the bridge from the Pangi forest reserve.

Kinabatangan Orang Utan Conservation Project (KOCP) co-director Dr Isabelle Lackman said this was the first photographic evidence of such an encounter.

"Over the years, we've received many sightings of orang utans using the rope bridges but no visual proof.

"These pictures clearly show that orang utans have used it to cross the Rasang river," she said here yesterday.

The bridge, built in 2003, was the first of six to be built for the orang utan population.

The photographs were taken by Ajirun Osman Aji, who claimed the orang utan spent about 20 minutes on the bridge before crossing it.

Lackman said in the past, orang utans would use giant trees as "natural bridges" to swing from one area to another.

But most of the trees had since been logged and thus made it difficult for the orang utans to move from one area to another.

There are an estimated 1,000 orang utans within the protected and non-protected areas of Lower Kinabatangan.

Sabah has an estimated 11,000 orang utans.