Mangrove synchronous
Pteroptyx spp.
Also called: Bent-winged fireflies
At a glance
- Flash
- Rapid, tightly synchronous flashing — whole trees pulse together, several flashes per second
- Habitat
- Mangrove and riverside trees along tidal rivers and estuaries
- Range
- Coastal Southeast Asia — Malaysia, Thailand, the Philippines, Indonesia
- Season
- Year-round in the tropics; displays are often best in the dry season
- Size
- 5–10 mm
- When active
- After dusk, returning to the same display trees each night
Overview
Pteroptyx are Southeast Asia's synchronous fireflies. Thousands gather night after night in the same riverside 'display trees' — often mangroves such as Sonneratia — and flash in near-perfect unison, whole trees pulsing together like a slow heartbeat. It is one of the most extraordinary displays in the natural world and a major draw for river eco-tourism.
The name 'bent-winged firefly' comes from the upturned tips of the males' wing-cases. The synchrony is an emergent behaviour: each beetle adjusts its own rhythm to its neighbours until the whole aggregation locks into phase, which biologists think helps females pick out males of their own species in a crowded tree.
How to identify
Not a lone flasher — Pteroptyx is seen as a mass, tightly synchronised display in specific trees along tidal rivers, with a greenish light. If a whole tree is blinking as one, this is the genus.
Conservation
Highly dependent on intact mangroves. Clearing riverside forest, coastal development, water pollution and bright boat lights all break up the displays — protecting the mangroves protects the spectacle.
Sources & further reading
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