Some loss of the Munduruku language is occurring among those who live in the area of the Madeira River and in the outskirts of the towns next to the Tapajós River; however, the situation is not as bad as it seems, as even here, the language of the majority of is Munduruku, and bilingualism only takes place after Munduruku has already been acquired (around 10 years of age), usually as a result of learning Portuguese at school.
Some decline in the Munduruku language is happening among those residing near the Madeira River and outside the towns adjacent to the Tapajós River; however, the situation isn't as dire as it appears, since even here, most people speak Munduruku, and bilingualism only occurs after Munduruku has been acquired (typically around 10 years old), usually due to learning Portuguese at school.