Rhinoceros hornbill

The bird

Field notes

You hear a rhinoceros hornbill twice before you see it: the honking duet, then the extraordinary rushing of air through its wingtips — the species never evolved the quiet feathers most birds have, so a pair passing overhead sounds like slow applause. The casque, that upturned scarlet-and-orange horn, is keratin over a honeycomb core: light, loud and unmistakable.

Pairs mate for years and commute the same routes, which is why guides can put you under a flight line with confidence. During nesting, the female seals herself into a tree cavity for months and the male feeds her through a slot — one of the great parental commitments in nature, happening quietly all over this valley.

Seen in Danum

Cross the canopy walkway at first light and you're standing in their commuting lane; the Study Centre's tower and Bukit Atur produce constant flyovers. Fruiting figs pull pairs in at any hour.

Best site & season

Reliable year-round; dawn and late afternoon are the commuting hours. Photographers should hold for the flight shot — the whoosh gives about two seconds' warning.

Find it on these

• Birdwatching in Danum — the full morning routine
• The Canopy Walkway — eye-level flight lines
• Wings & Wonder — 4D3N — the dedicated birding itinerary