The Kuala Selangor Fireflies

Along the Selangor river, colonies of a small firefly settle in berembang trees on the bank and flash together, so that whole trees pulse in time. Two main operations run trips: Kampung Kuantan, where oarsmen paddle four-person sampans in silence, and Kampung Belimbing, which uses small motorboats. Departures start after full dark and last about twenty minutes on the water. Nearby, Kuala Selangor Nature Park protects mangrove and mudflat with boardwalks, silvered leaf monkeys and migratory waders, which makes a reasonable way to fill the afternoon before the boats begin. The fireflies depend on the mangrove staying intact, and numbers vary with river conditions.

What you actually see

• Synchronised flashing - whole trees pulsing in time along the riverbank.
• The paddled sampans - silent four-person boats at the Kampung Kuantan jetty.
• Kuala Selangor Nature Park - mangrove boardwalks with silvered leaf monkeys.
• The mudflats - migratory waders on the estuary at low tide.

When to go

Boats run after dark, typically from around eight in the evening, and the display is best on moonless nights without rain. Weekends are busy and the queue at the jetty can be long. Kampung Kuantan works on a first come first served basis rather than bookings, so arrive early. Avoid nights following heavy upstream rain.

Honest expectations

The trip on the water lasts about twenty minutes, which is short for the driving involved. Photography is effectively impossible without specialist gear, and phone flashes from other boats ruin the darkness for everyone. Numbers fluctuate, and a poor night looks like a few scattered sparks. The motorboat operation is noisier and less pleasant than the paddled one.

Nearby

Kuala Selangor town and Bukit Melawati; the Sky Mirror sandbar at Sasaran is close by.