BAOMO, Kenya -- The women approached the visitors in formation, the eldest at the rear, where they would remain, fully dressed. The younger ones cavorted in front, chanting, clapping and, at the climactic moment, turning their backs and hoisting their skirts toward their visitors -- a half-dozen men of science struggling to maintain the detachment befitting their profession.
"That was to curse us," said Ronald Mwangangi, recalling the scene at this remote oasis two months ago.
Mwangangi had come with his fellow primate researchers to scan the lush riverside treetops for a rare colobus monkey. When the Baomo village women mooned them, it was in hopes of driving away intruders they assumed wanted local land to expand the nearby Tana River Primate Reserve.
The encounter was, on one level, a routine if exceptionally vivid example of the chronic tension between African tradition, which places ancestral land in the hands of local tribes, and the modern African state, which in Kenya as elsewhere reserves land in the hands of the government.
But that open conflict pales beside the conflict inside the stunned men who watched 50 mothers show them their bare backsides. Like almost everyone raised in this part of Africa, they understood that the sight was intended to hasten their deaths. By flashing their private parts, local residents said, the mothers had not only insulted their targets but reminded them where they had come from.
"They said we were going back to the womb," Mwangangi said. "You can be educated, but that sort of traditional practice has got a lot of influence on you -- deep."
The battle of the Tana River Primate Reserve, a meandering glade an hour from the Indian Ocean, illustrates the tension at the heart of a changing Africa. Often dismissed as backward, it is a place that is both bound and sustained by tradition, its people reluctant to surrender a view of daily life that might be the envy of questing Western movements from communitarianism to New Age.
The land issue here has simmered since 1976, when the reserve was first sketched on maps and the people who had been farming it were informed they would not be allowed to expand their plots. But expand they did, and as pressure grew on the unique ecosystem, a tangle of shade trees favored by the rare red colobus and mangabey monkeys, the Kenya Wildlife Service offered the residents free land elsewhere, plus a house, a school and water. The World Bank put up the money.
Not everyone wanted to move. "This has been their ancestral land," said J.W. Irungu, the deputy district commissioner. The relocation program is voluntary, but the passions around it swelled until almost everyone associated with the reserve had been exposed to the bare backside curse.
But it didn't make the Nairobi newspapers until this month, when a dozen researchers were evacuated from a remote village after the women showed up after dark. "Naked women scare scientists," read the headline in the Daily Nation.
The story was met with giggles that, in some quarters, became the precursor to grave discussions.
"When you see African women stripping, that is a very serious matter," said Islam Juma, a teacher who grew up near here. "They are collaborating with the environment." Indeed, the women had concluded their protest by picking up a handful of sandy gray soil and flinging it at the researchers.
To people who live so close to the land, Mother Earth is not an environmental slogan but the essential fact of life. Seventy percent of Africans reside in rural areas, and all but a tiny fraction of the rest were raised in villages whose spiritual traditions survived the arrival of Christianity and Islam. Across the continent, those beliefs locate the divine in ancestors and the Earth that sustains them.
"Us from the Abrahamic religions, we look up for God," said Sultan Somjee, an ethnic Indian and Muslim who conducts ethnic research for the Mennonite Church in Nairobi. "The Africans, they look down."
Thus, a few miles upstream from the reserve, the custom when a man takes a bride is for his parents to gather at a "tree of peace," pluck a blossom and ask the plant to "let them produce just as you are producing the flowers," said Hussein Dado, a teacher in nearby Madogo.
"And we are Muslims," he said. "We go to pray five times a day."
A group of women who stripped naked in downtown Nairobi eight years ago to protest police torture were Christians. The police beat them to disperse their demonstration, "and they resorted to something they knew traditionally would act on the men," said Wangari Maathai, one of those who tore off her clothes and saw young policemen turn their faces away. "They stripped to show their nakedness to their sons. It is a curse to see your mother naked."
"See, the government operates like a Westerner, following laws which are really Western laws," explained Maathai, who heads the populist environmental Greenbelt Movement. "And the local people at that time were acting very local."
Many educated Africans argue that certain traditional beliefs can retard progress, especially beliefs driven by fear. Along the Tana, for instance, the local district commissioner lives in a house that costs a fraction of what he can afford. Living more grandly would surely invite an evil spell from a jealous constituent.
It is a logic heard frequently in rural Africa, accounting for everything from the sight of a rich man changing into rags before returning to his home village to the failure of a student to raise his hand when he knows the answer.
"Jealousy will bring witchcraft," one local resident explained.
And yet, even in places as anchored in the ages as Tana, the past shows signs of slipping away. Mbaruk Suleman, who led the researchers cursed this month, said the revelry surrounding the women's display indicated "even they themselves didn't believe it would work. In the olden days, it would be done very solemnly, with a ceremony."
In the nearby village of Maramba, Omar Komora voiced his complaints to visiting World Bank and Kenya Wildlife Service officials. One speaker had grumped about the relocation program. To that, Komora added "the problem of witchcraft."
"When you stay around the river, a crocodile is sent for you and you may find yourself disappearing below the water," he explained when asked to elaborate. "Also, there are snakes."
The crocodiles, Komora said, are sent "by those people who oppose the program."