Nomads in a Dwindling Rain Forest. PENAN OF SARAWAK

THE Penan of Sarawak, nomadic jungle dwellers of Borneo's rain forest, have qualities that set them apart from other indigenous groups on this largest island in Southeast Asia. They are quiet and attentive; they are gentle and smile back at strangers. On the bank of the Tutoh River here in Mulu National Park, they cock their heads to gaze at foreign visitors with an almost sleepy wonder.

These people are having to adjust rapidly to a new and very different life. About 10 years ago, before Mulu National Park was formed, Cheng Kiyaa's family roamed the rain forest, staying in one spot only while game and wild vegetation were abundant.

Kiyaa's family built shelters, or ``sulap,'' of palm leaves and bamboo bound with rattan. He and his people ate the core of the wild sago palm as their staple starch. They slashed the bark of the tacem tree, collected its white sap, and made a poison for their blowpipe darts strong enough to kill a wild pig in three minutes.

Today the government encourages the Penan to settle, rather than wander in this newly created national park.

Cheng Kiyaa is now a retired elder of this settlement or ``kampong'' at Batu Bungan just outside the park. The government gave his people roofing material, seed, and basic know-how to plant and cultivate hill rice and tapioca. ``But,'' says Mr. Cheng, ``the government did not tell us how to manage our new way of life, and this is still a sore point. We don't like to talk about it among ourselves,'' he says, ``only when visitors ask.''

Cheng and his kampong are in many ways better off than they realize. Mulu Park is next door, where they may find jobs as laborers or porters. They can sell their crafts to tourists. Most important, they can go there to hunt - blowpipe only - and in the process retain many of their traditional values.

In the upper reaches of an entirely different Sarawak River Basin, another group of Penan are adjusting to harsher realities. At Samling Timber Company Camp C, on the Wat River, there is no park or refuge. The once-clear waters are murky with runoff. On one side of the river, growling diesel machinery plows thin tropical topsoil, making or widening access roads. On the other side are two small shelters, built out of milled lumber and roofed with corrugated sheet metal.

Ulig Beti, son of one of the three leaders at this settlement, says his people did not know of plans to fell trees on their land until Samling sent word asking for employees.

``We want them off our land,'' says Ulig, ``but what can we do?''

The Penan at Camp C came here not so much for employment as to claim compensation for the company's use of their land. Meanwhile, some work as laborers. Others trade their crafts - baskets and the machetelike parang - for supplies and food.

At the moment, wild plants such as the sago palm are abundant. Hunting, however, has already decreased. Fish in the Wat River, once abundantly varied, are now limited to two: catfish and carp, species adapted to murky waters. If the pace continues, Sarawak's rain forests may be logged out in as little as 20 years.

If the Penan of Sarawak are not to follow in the footsteps of the North American Indians, the Australian Aborigines, the New Zealand Maoris, and others, they will need help.

They'll need strength, flexibility, and a government policy that will allow them to adapt at their own pace, without destroying their only natural resource: mature and undisturbed jungle.