Emmon’s Tree Rat re-discovered at the Danum Valley Field Centre

Emmons’s Tree Rat Pithecheirops otion is one of the most rare mammals in Borneo, with only one specimen ever collected and no photographs taken in the wild.

Since the original collection by  American zoologist Louise Emmons at Danum Valley Field Centre of a single sub-adult male on 21 September 1991,  there have been no further reports until now. Emmons (1993) A new genus and species of rat from Borneo

As shown by the superb photographs below this long wait is finally over.

During a stay at DVFC in January 2024, American academic Ben Schweinhart photographed two different individuals  in the forest surrounding the DVFC main buildings.

A possible explanation for the apparent rarity  and temporary local abundance maybe that Pithecheirops otion normally feeds in the canopy but will feed lower down if a favoured small fruiting tree is masting locally.

Thanks to Ben Schweinhart for all information and photographs.