Bumdeling Wildlife Sanctuary

Bumdeling is the other place black-necked cranes winter in Bhutan — the small, quiet, eastern one, a short drive north of Trashi Yangtse town. Come between November and February, allow half a day, and expect to have the valley more or less to yourself.

How many cranes are actually here?

52 in the 2024–25 season. Phobjikha had 640 the same winter, out of 709 across the country.

That is worth saying plainly, because most pages about this place still print “about a hundred birds” — a figure that was roughly right ten or fifteen years ago and has not been revised since. Bumdeling’s biggest recorded flock was 184, in 1998; 60 came in 2010–11, when 368 wintered in the country as a whole. The national total has since climbed to 709, and this valley has not climbed with it.

None of which is a reason not to come. It is a reason to come knowing what you are coming for: a handful of very large birds on an open valley floor, with nobody else watching them. If you want the spectacle, that is Phobjikha. If you want the east, and quiet, this is it. Numbers are counted every winter — ask us for the current one before you plan around it.

What else is in the sanctuary?

About 1,520 km² of it, running from 1,500 m to 6,000 m across three districts — Trashi Yangtse, the Khoma end of Lhuentse and Mongar — with its northern boundary on Tibet. It was established in 1998 and absorbed the older Kulong Chu sanctuary. Singye Dzong, the closed pilgrimage valley, sits inside it at the Lhuentse end.

• Bhutan’s national butterfly was discovered here — Ludlow’s Bhutan Glory, Bhutanitis ludlowi, found by Frank Ludlow and George Sherriff in the upper Trashiyangtse valley in 1933–34 and not described until 1942. It is Endangered on the IUCN list. It was long thought to live only in Bhutan; it has since been recorded across the border in Arunachal Pradesh, which makes the range small rather than singular.
• A Ramsar wetland of international importance — site 2032, designated in 2012, among Bhutan’s first. As at Phobjikha, the Ramsar listing covers the wetland, not the whole sanctuary.
• A BirdLife International Important Bird and Biodiversity Area, and good birding well beyond the cranes: pheasants, laughingthrushes, warblers and raptors across a range of forest types.
• On UNESCO’s tentative World Heritage list — which is the queue, not the register.
• About 3,000 households live inside the boundary. This is farmed, grazed, inhabited country, not a wilderness reserve, and the cranes feed in people’s fields — the same arrangement, and the same tension, as Phobjikha.

There is a 600 MW hydropower project on the Kholong Chhu, the river that runs down through the sanctuary and past Trashi Yangtse town. It has changed owners and name more than once and we will not guess at a completion date. It is not a sight and we are not sending you to look at it — but it is the largest thing happening in this valley, and it is happening on the river the cranes winter beside.

Getting there, and the permit

Entry needs a forestry permit, obtained through a licensed Bhutanese operator. There is no gate to pay at, but it is paperwork rather than a formality — so ask us while the trip is still being planned rather than on the morning you want to go.

The Bumdeling valley, where the cranes are, is roughly 8–10 km north of Trashi Yangtse town, which is itself about two hours from Trashigang. The crane ground is a level valley floor and you watch from the edge of it. Anything beyond the valley — the high lakes, the passes, the Lhuentse end — is a trek rather than an outing, and needs planning rather than an afternoon.

This does not fold neatly into the standard Yangtse day. Half a day here, plus four hours of driving out and back from Trashigang, is a day of its own — so either the town sights give way to the cranes, or you ask us about a night in Trashi Yangtse. See things to do in Trashi Yangtse for what the rest of that day would otherwise hold.