I kept my flash toned down and at an angle to illuminate the tarsier's special features: its toe pads for clinging to small trees, the sensitive, directional ears and those huge eyes for night vision.

A tarsier is known for its big, beady eyes, but it's only when you look at a skull of this diminutive South East Asian primate that you realise just how big they are. Each one is the same size as ...