Muong Te Nature Reserve

At six in the morning, in the forest of Mường Tè, a sound rises from the mountainside before the light is clear. It is low and long, then it climbs high, like a conversation between two different voices. It is the duet call of the white-cheeked gibbon, a critically endangered primate marking its territory at dawn.

That sound has become rare in Vietnam. The Mường Tè Nature Reserve is one of the few places that still offer it.

The reserve lies in two communes, Tà Tổng and Mù Cả. They are part of Mường Tè, in the west of Lai Châu Province, where it borders Laos. It is about 200 kilometers from Lai Châu city. It was founded in 2002 to protect the forest ecosystem typical of the northwest, and its rare animals and plants.

This is no ordinary reserve, because of how rare the species living in it are.

Start with the numbers. The forest holds 542 species of plants. Of these, 57 are listed in the Red Book of Vietnam. Seven are listed in the world Red Book of the IUCN. And 22 are narrowly endemic: they grow only in the northwest of Vietnam, and nowhere else on Earth. Among the trees are trám đen and chò nước. There is also lát hoa. These are precious timber trees, which many other forests lost long ago.

Beside the plants, three animals are worth knowing by name, because they are among the most endangered creatures still left here.

The first is the white-cheeked gibbon, Nomascus leucogenys. The male has black fur, and the female has cream-yellow fur. Every morning they sing together to announce their territory. The male's call is low. The female's is higher and longer. In the quiet forest at dawn, the sound carries for a few kilometers. This species is critically endangered.

The second is the snub-nosed monkey, Rhinopithecus avunculus. It is a primate found only in Vietnam, and in no other country. It is ranked among the 25 most endangered primates in the world. Only a few hundred individuals remain on the whole planet. The reserve is reported to be one of the few places that still records this animal.

The third is a bird, the gà lôi lam mào trắng, Lophura edwardsi, which is reported here as well. It is critically endangered too.

These are not rare in the ordinary way. They are living things that, once lost, cannot be brought back.

Anyone who gets up at six and stands still in the forest may hear the call from far away. It would be one of the most remarkable natural sounds of the northwest.

The Mường Tè Nature Reserve is not an easy place to reach. But what it keeps inside, no other place has.