A Diana monkey perched in the rainforest canopy on Tiwai Island, backlit by shafts of morning light filtering through the Moa River forest
← Sierra Leone

Tiwai Island

"I heard the chimps before I saw anything — a low, building sound that vibrated in the chest before it reached the ears."

Tiwai Island Wildlife Sanctuary sits in the Moa River in southeastern Sierra Leone, a few kilometers from the Liberian border. It’s not a place you arrive at accidentally. The road from Kenema takes the better part of a day, the final approach involves a dugout canoe across the river, and the camp itself runs on generator power that cuts out reliably at ten. I’d done this kind of math before and found it consistently worth it. Tiwai did not argue with this pattern.

Eleven Primate Species

The statistic that keeps appearing in descriptions of Tiwai — eleven primate species in an area of roughly twelve square kilometers — sounds like a brochure exaggeration until you’re standing in the forest at 6 a.m. watching it demonstrate itself. My tracker that morning, a ranger named Joseph who had spent the better part of fifteen years on this island, moved through the undergrowth in near-silence, pausing to interpret sounds I couldn’t yet parse.

We found the chimpanzees in under an hour. A group of eight, moving through the mid-canopy, one adult male watching us from a branch with the alert, calculating expression of someone deciding whether we were worth bothering about. We stood still. He decided we weren’t. The group moved on.

Later: Diana monkeys in a feeding tree, their white beard markings almost theatrical. Red colobus moving in the upper canopy with that distinctive rhythmic leap. Western black-and-white colobus motionless in a shaded branch, doing what colobus do best, which is looking decorative and judgmental simultaneously.

Pygmy Hippos at Dusk

The pygmy hippo is one of those animals that sounds invented until you see one. Smaller and more solitary than its common cousin, critically endangered, nocturnal by preference — Tiwai has a population that’s among the most accessible in the world, which still means considerable patience and some luck. The evening walk to the mudflats near the river’s edge is mandatory here.

I saw one my second night. It emerged from the reeds at the water’s margin around seven in the evening, moving with the unhurried deliberateness of something that has no natural predators on this island. I watched it for perhaps ten minutes. Joseph watched me watching it with the quiet satisfaction of someone who’s been showing this animal to disbelieving strangers for years.

The Forest Itself

Even without the wildlife counts, the forest on Tiwai would be worth the journey. The canopy is intact in a way that feels increasingly rare — tall enough that the light arrives green and filtered, the air correspondingly humid and rich with something I can only describe as biological density. Every surface is occupied. The soundscape at dawn, before the heat builds and the birds go quiet, is extraordinary. I lay in my camp bed on the first morning and didn’t move for thirty minutes, just listening.

Camp and Practicalities

The camp is basic but not uncomfortable: simple cabins with mosquito nets, a communal dining area, bucket showers. Meals are prepared by staff and are better than the infrastructure suggests — rice and sauce, fresh fish from the river, fruit that appeared without announcement. The ranger fees go directly toward the sanctuary’s maintenance and local staff wages, which made paying them feel like the least complicated transaction of the trip.

When to go: November to May, the dry season, when the forest trails are passable and river levels allow easy canoe crossings. The rains from June to October can make trails impassable and the river crossing more difficult. January to March offers optimal wildlife viewing — the dry conditions concentrate animals near water sources and visibility through the undergrowth improves considerably.