Deer Cave Bat Emergence — Mulu Sarawak Malaysia
The Deer Cave in Mulu National Park — with a 90-metre-wide, 120-metre-high entrance passage (the world's largest cave passage by cross-section), housing 3–4 million wrinkle-lipped bats (Chaerephon plicatus) in a roost that produces one of Borneo's most spectacular daily wildlife events: the bat emergence at dusk. From the observation platform 200 metres from the cave mouth, the bats exit in a continuous column for 20–40 minutes, the column's movement creating undulating shapes above the lowland dipterocarp forest as the bats navigate in coordinated streams to their nightly feeding grounds. Bat hawks (Macheiramphus alcinus) hunt the emergence's edge in the fading light, and the combination of the cave mouth's scale (visible from 500 metres as a dark oval in the limestone cliff), the bat column's movement, and the sound of 3 million pairs of wings creates one of Borneo's most accessible and most consistently spectacular daily wildlife events.
About this spectacle
At dusk each evening, millions of wrinkle-lipped bats stream out of the world's largest cave passage by cross-section — a 90-metre-wide, 120-metre-high mouth carved into a limestone cliff face in Gunung Mulu National Park. Visitors watch from a dedicated observation platform roughly 200 metres from the cave mouth as the colony, numbering 3–4 million individuals, pours out in a continuous, undulating column that can last 20 to 40 minutes. The column twists and pulses against the darkening sky above the lowland dipterocarp forest, and the collective rush of wings fills the humid evening air with a low, sustained roar. Bat hawks (Macheiramphus alcinus) slice along the column's edges, picking off individuals in the fading light. The sheer scale of the cave mouth — visible as a dark oval from 500 metres away — adds a dramatic geological backdrop to the biological spectacle. It is one of Borneo's most reliably delivered wildlife events, occurring every clear evening regardless of season.
When to go
Year-round
Getting there
Nearest airport: MZV. Nearest city: Miri.
Booking options
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