Then, in 1988, the Brazilian government created a new Constitution that established rights for indigenous people. Among them: giving Guaraní and other indigenous families the right to repossess their ancestral land, a process that has been slow and frustrating for both Indians and farmers and that has put them even more at odds.

In many cases, farmers, too, have lived in Mato Grosso do Sul for generations. They raised their families there, and worked and profited from the land, first from maté (a kind of tea), and later from sugar cane and soybeans. Like the Guaraní, they are rooted in the land, making the conflict between landowners and the Guaraní both cultural and material. Where the indigenous see repossession of their ancestral land as integral to revitalizing their cultural traditions and regaining their sense of well-being, ranchers and farmers view it as a hindrance to Brazilian progress and development.

James Anaya, the United Nations special rapporteur on the rights of indigenous peoples from 2008 to last May, said suicides among indigenous youth, across the globe, are common in situations where tribe members have seen the upheaval of their culture, which produces in the indigenous a lack of self-confidence and grounding about who they are.

In the southwest of Brazil, he said, distress, poverty and violence against tribal leaders have led to despair among Guaraní teenagers, who feel they don’t have a future. “They see taking their own lives as unfortunately and sadly an option,” he said.

Professor Alcantara said that over the past 10 years tribe members have come to live between two cultures — the culture of nearby cities, where they are discriminated against, and the culture of their own tribe. Young tribe members, in particular, feel that they don’t belong either to the city or to the tribe, she said.

Tonico Benites, a Guaraní and anthropologist, said that during Brazil’s dictatorship of the 1970s and ’80s, conditions on Guaraní reservations deteriorated: There was overcrowding and families were split apart. Today, the situation has grown even worse, he said, and many Guaraní feel lonely and isolated.

“At some point, many people I knew, friends, had lost their autonomy, their way of supporting themselves,” he said. “So they end up thinking about death.”