YOUNG orphans Bula Mata and Rieke have moved into Monkey World's playroom crèche - just in time for World Orang-utan Day.

It is hoped the Sumatran orang-utans, who have been cared for by specialist staff since arriving separately at the ape rescue centre, will now integrate with other orang-utans at the park.

Monkey World director Dr Alison Cronin said: "Bulu Mata and Rieke have made great progress since arriving.

"Both babies have put on weight, have been teething and are now climbing, playing and developing very strong muscles.

"This is really important as we are planning to introduce them to the rest of the orang-utans in our nursery group in the coming weeks.

"It is essential we know the babies are strong enough and co-ordinated enough to move about the huge nursery climbing frame on their own."

World Orang-utan Day, part of the campaign to help preserve the species, is marked on August 19.

The current population of Sumatran orang-utans in the wild is estimated at 7,300 and they are classed as a critically endangered species.

Monkey World at Wool is home to the only European crèche for orphaned orang-utans. The building has a gymnasium-sized playroom fitted out with climbing frames, hammocks and ropes.

Six other orang-utans also live there, including orphans from the UK, Spain, Taiwan, Hungary and South Africa. Some of these were smuggled from the wild before being confiscated from the black market trade.

Baby girl Rieke arrived at the Dorset centre from Berlin Zoo in February, having been rejected at birth by her mother.

Bulu Mata arrived from Budapest Zoo, last December, after his mother died unexpectedly.

Dr Cronin said: "Their safety is paramount but it is almost time for them to join the other orang-utans full time."

Visit monkeyworld.org for details about how you can help the primates there.