Fireflies on the Iwahig River

Drift in silence along a mangrove river at night while mangrove trees sparkle with thousands of fireflies, like Christmas lights strung by the forest itself.

Area

Puerto Princesa

Start from

Puerto Princesa city

Distance

about 20 km southwest of the city

Time needed

An evening

Best season

All year; best on dark, moonless nights

Difficulty

Easy

Transport

Van or tricycle to the river, then a paddle boat

Tickets & rules

Tour fee; often booked through tour agencies

Why go

This is my favourite evening near Puerto Princesa, and one of the quietest experiences in all of Palawan. You arrive at the river after dark, put on a life vest and step into a small paddle boat. The guide pushes off without a motor, and within a few minutes the lights of the landing stage are gone and there is only the sound of water and insects.

Then the trees begin to glow. Thousands of fireflies gather in particular mangrove trees, flashing in loose rhythm, so that whole branches seem to blink on and off. Above, if the sky is clear, the stars are reflected in the still water. It is hard to tell where the insects end and the sky begins.

The guides are often local fishermen from the riverside community, and they point out the trees with a dim red torch, tell stories about the mangroves and sometimes about the spirits believed to live in them. Nobody talks loudly. You don’t photograph much, either; it is one of those things that film cannot hold.

The story

The Iwahig River flows past the Iwahig Prison and Penal Farm, established by the American colonial government in 1904. It was set up as an open prison where inmates could farm, fish and live in small communities, often with their families, rather than being kept behind walls. It still operates today, and the colony grounds, fields and old buildings make a curious detour on the way.

The firefly tours began as a community project to provide an income for local families while protecting the mangroves. The fireflies depend on healthy mangroves for food and breeding, so the communities have every reason to protect them. It is a small example of how tourism can support conservation.

Fireflies flash to attract mates, and in some species the males in a tree synchronise their flashes. Scientists still debate how this coordination emerges, but sitting in the dark, you don’t need an explanation. It simply feels as though the forest is breathing light.

Getting there

Book a tour through an agency in Puerto Princesa or at your hotel; transport, the boat and a guide are usually included. The drive takes around 40 minutes. Tours run after sunset, typically between 18:30 and 21:00.

If you have time, ask the driver to pass through the Iwahig colony grounds in daylight on the way; the farm fields and old buildings are an unusual glimpse of the city’s history.

A suggested plan

1. 18:00Pick-up in the city and drive south toward Iwahig.
2. 18:45Briefing at the riverside and life vests on.
3. 19:00Paddle quietly along the river among the glowing trees.
4. 20:00Return to the landing, perhaps with a snack at a roadside stall.
5. 20:45Back in the city for a late dinner.

Where to stay

Stay in Puerto Princesa city; the tour is a simple evening outing.

Good to know

• Go on a moonless or cloudy night for the brightest display.
• Wear long sleeves and use repellent; mosquitoes are out too.
• Turn off your phone screen; light disturbs the fireflies and other visitors.