Milly was picked to trek to Borneo and is looking forward to "getting out and seeing the world".
The artefact was acquired in 1923 by Pitt Rivers Museum - where it has never been displayed.
The arrival of such a rare Bornean orangutan was "incredibly special", Chester Zoo says.
Recovering forests offset just 26% of carbon emissions from new logging and wildfire, say scientists.
Lawmakers approve proposals to relocate the capital from Jakarta, which is sinking at an alarming rate.
Scientists map ancient underwater landslides in the region chosen for Jakarta's replacement.
Orangutans rescued from captivity and rehabilitated live in the surrounding forest.
Peter Kallang has been awarded a top environmental prize for a successful campaign to stop a mega-dam being built in Borneo.
Activists say moving the capital to Borneo threatens indigenous people and Kalimantan's rich wildlife.
