Indigenous Baby Nursing in the Xingu Indigenous Park.  The fecundity (birth rate) among the indigenous Amazonian people in Brazil is five births per mother compared to a national average of only two.  This high fecundity has contributed to the rapid recovery of many Brazilian indigenous tribes in the last thirty years.  Some tribes, such as the Kamayura, dwindled to as few as 94 individuals in the 1950's.  At present, the Kamayura tribe is a vibrant culture with 355 members of their tribe speaking Kamayura as their primary language.