The lowland forest trails hold the crested black macaque — a jet-black, crested primate with startling amber eyes, made famous by the monkey selfie copyright case. Habituated groups are located by rangers most mornings and can be followed on foot at close range as they forage and groom.

The strangler fig trees near the ranger post are the tarsier sites. Spectral tarsiers — tiny nocturnal primates with enormous eyes, weighing about as much as a mobile phone — sleep in hollows within the figs and emerge at dusk in a rush of movement. Guides know which trees are occupied that week, and the emergence happens within a predictable few minutes.

The forest generally holds the rest of the Sulawesi endemics: knobbed and red-knobbed hornbills, Sulawesi dwarf kingfisher, bear cuscus in the canopy, and a long list of birds found only on this island.

The black sand beach at the reserve edge is where maleo — a megapode that buries its eggs in volcanically warmed sand and abandons them — can sometimes be seen, though the species has declined sharply and sightings are far from guaranteed.

The drier months from May to October make trails easier; wildlife is present year-round.

Practicalities

Tangkoko is around two hours by road from Manado, which is served by domestic flights and is also the base for Bunaken's diving — the two combine naturally into one trip.

Guides are compulsory and hired at the entrance; the good ones know individual macaque groups and tarsier trees. Keep your distance from the macaques and wear a mask if asked — habituated primates and human disease are a serious combination.