The Ka'apor are a distinct ethnic group of indigenous Brazilians living on a protected reserve in the state of Maranhão

Maranhão

Maranhão is a northeastern state of Brazil. To the north lies the Atlantic Ocean. Maranhão is neighbored by the states of Piauí, Tocantins and Pará. The people of Maranhão have a distinctive accent...

. They were the subject of a book by anthropologist Dr. William Balée

William Balée

William Balée is a professor of anthropology and environmental studies at Tulane University in New Orleans, Louisiana. He was born in the Miami, Florida area and educated at the University of Florida, Gainesville, where he received a B.A. in Anthropology before moving on to Columbia University in...

 in an exhaustive study of their ethnobotany lifeways and the historical ecology

Historical ecology

Historical ecology is a research program that focuses on the interaction between humans and the environments in which they live. Rather than concentrating on one specific event, historical ecology aims to study and understand this interaction across both time and space in order to gain a full...

 of the area they currently inhabit.

They live in a heavily deforested area of Pre-Amazonian forest, but have managed to protect the forest within their designated reserve up until now.

There is a high degree of congenital deafness among the Ka'apor, and consequently most of the hearing community knows sign language

Sign language

A sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...

. (See Ka'apor Sign Language.)