Nancy M. Flowers

Ecology and Acculturation Among Native Peoples of Central Brazil

Simple exposure to Western goods may not be a sufficient explanation of why isolated village communities increase their participation in external market economies. The degree of market participation by four native villages in central Brazil is related to the difficulty of making a living from slash-and-burn subsistence agriculture as measured by the ratio of labor input to food output.

Subsistence productivity and hunting effort in native South America

The question of why people work more or less at various activities is an old one in anthropology and recently has surfaced in studies of native South American societies. Growing out of debates about protein scarcity, arguments have arisen over the reasons why people spend time on hunting and fishing. Some authors suggest that labor allocation and other societal features can be explained with reference to absolute minimum requirements for specific nutrients (e.g., protein). This study presents data from four native Central Brazilian societies on the time spent at various subsistence tasks and the productivity of those tasks. The evidence suggests that decisions to allocate labor to hunting and fishing are influenced more by the overall possibilities for production in an area than by the availability of animal proteins alone. Satisfaction of calorie requirements appears to take precedence over satisfaction of protein requirements. In those societies in which gardening is highly productive, people can spend more time on hunting and fishing and improve the overall quality of their diet.

Hepatitis B epidemiology and cultural practices in Amerindian populations of Amazonia: The Tupí-Mondé and the Xavánte from Brazil

Hepatitis B infection and disease are highly endemic in South America. Prevalences of positivity are particularly high in Amazonia, and among Amerindian peoples in particular. This paper reports the results of a seroepidemiological survey for hepatitis B virus (HBV) carried out among four Amerindian populations from the Brazilian Amazon region: Gavião, Surui, Zoro and Navate. Rates of positivity to HBV serological markers (HBsAg, anti-HBs and or anti-HBc) are very high for the four groups, ranging from 62.8 to 95.7%. It is argued that the high rates of positivity in the Amerindian groups dealt with in this study, as well as for other Amazonian populations, are related to a complex of cultural practices which enhance the likelihood of HBV transmission (bloodletting, scarification, tattooing and orally processed food, among others). The authors suggest that, due to unique patterns of interaction between sociocultural and environmental factors. HBV infection assumes a specific profile in native Amazonian societies.

Endemic pemphigus foliaceus (fogo selvagem) in Native Americans from Brazil

BACKGROUND Fogo selvagem (FS) is an autoimmune disease that is endemic in certain regions of Brazil and appears to be precipitated by an environmental factor. OBJECTIVE Our purpose was to confirm the occurrence and prevalence of FS in a population of Xavante Indians living in an endemic region of central Brazil. METHODS Clinical, anthropologic, and immunologic studies were carried out in patients and in normal inhabitants of the Pimentel Barbosa Indian Reservation, Mato Grosso, Brazil. RESULTS FS was identified and confirmed in 10 patients from a patient pool of 295 with various skin diseases. The Xavante settlement has a total population of 746. Anti-desmoglein 1 autoantibodies were detected in all patients with FS and were absent from more than 300 serum samples collected from randomly selected unaffected persons. CONCLUSION FS is strongly linked to outdoor activities and is largely restricted to immunogenetically predisposed persons. FS appears to have been endemic in certain regions of South America for several centuries.

Intestinal parasitism in the Xavánte Indians, Central Brazil

This paper reports the findings of a survey for intestinal parasites among the Xavánte Indians from Central Brazil. A. lumbricoides (25.0%) and hookworms (33.6%) were the two most common helminths; E. histolytica complex (7.8%) and G. lamblia (8.6%) the most common protozoans. The majority (58.5%) of positive individuals hosted only one species of helminth. Egg counts for helminths, and for A. lumbricoides in particular, were found to be not dispersed at random, with a few individuals, all of whom young children, showing very high counts. The prevalence rates of intestinal parasites for the Xavánte are below those reported for other Amerindian populations from Brazil.

Tapirs, Tractors, and Tapes: The Changing Economy and Ecology of the Xavante Indians of Central Brazil

This paper explores the process of change in a Brazilian indigenous community, relating it to historical, economical, and political forces at the regional and national levels, as well as to environmental variables. In the light of current fieldwork, we examine the predictions of a model constructed 20 years ago based on fieldwork in this and three other Indian communities of Central Brazil by Daniel Gross and collaborators. This model ascribed involvement in the market economy of small-scale communities primarily to land circumscription and resulting environmental degradation, increasing the labor cost of subsistence food production. We find that in the case of the Xavánte community entry into the market was more the result of a top-down government plan to implement mechanized rice production on Xavánte reservations. With the collapse of the project the Xavánte have, on the one hand, returned to a more “traditional” economy based on hunting, gathering, and swidden agriculture and, on the other hand, are innovating by marketing their cultural image through connections with national and international environmentalist organizations.

The Brazilian Xavante Indians revisited : New protein genetic studies

A total of 94 individuals from the Xavante village of Rio das Mortes were variously studied in relation to 28 protein genetic systems. No variation was observed for 15 of them, in accordance with previous studies. Of the remaining 13, four (Rh, Duffy, acid phosphatase, and GC) showed significant departures from the averages obtained in 32 other South American Indian populations. If studies performed in the 1960s are considered, there is indication that no significant changes in this villages gene pool has occurred in the last 30 years. Comparison with two other Xavante populations included nine systems with variation, and for three of them (MNSs, Rh, and Duffy) significant differences were found. Genetically the Rio das Mortes are closer to the São Marcos than to the Simões Lopes Xavantes. A dendrogram considering 25 genetic systems and 33 South American Indian populations was constructed. There the Xavante were grouped together, in two neighboring clusters, with three other tribes who speak Ge languages, But these clusters also present populations who speak other languages, and the reproducibility of the tree is low. South American Indians, at least with this set of markers, do not seem to be clearly classified into defined subgroups.

Variation in Swidden practices in four central Brazilian Indian societies

It has been suggested that indigenous tropical forest agriculture, in contrast with other agricultural systems, is characterized by a high degree of polyculture, and, being similar in diversity to the forest itself, has little disturbing effect on the generalized ecosystem that surrounds native gardens. Our comparative study of four Central Brazilian Indian groups shows, however, that while each of these groups practices polyculture to some extent, the crop mix found in their swidden plots is highly patterned, and includes single crop stands at certain stages of garden life. Different crops are planted in the same swidden plot from year to year, in accordance with variation in soil fertility within the swidden cycle. None of the swiddens we observed compares in complexity to the surrounding forest. We suggest that polyculture, rather than being regarded as the distinguishing characteristic of swidden cultivation, should be considered as a varying dimension—along with other variables such as use of wild plants, soil fertility and exhaustion, tillage practices, the introduction of novel crops, and production for the market—within the overall subsistence strategy of a group.

Demography and health of the Xavante Indians of Central Brazil

This study investigates the demographic and health behavior of the Xavante Indians of Mato Grosso State, Central Brazil. Data covering the period 1999 to 2004 was collected using information from household censuses and vital statistics. In addition to standard demographic analyses, survival analysis was carried out. Results show a young age structure, derived from a combination of high fertility rates (7.7 live births per woman) and declining mortality. Mortality rates, especially infant mortality (97 per thousand), remain very high, surpassing regional and national rates. Natural increase is the main contributing factor to population growth. The annual population growth rate is 4.4%. Results suggest that recent declines in mortality and fertility may be related to transformations in the implementation of basic health care services and internal diversity, the latter of which seems to be associated with local history and sociocultural determinants.

Pênfigo foliáceo endêmico (fogo-selvagem) no grupo indígena Xavánte, Mato Grosso, Brasil

Foi realizado inquerito soro-epidemiologico atraves de testes de imunofluorescencia indireta e imunoprecipitacao visando determinar a prevalencia do penfigo foliaceo endemico (PFE) na populacao indigena Xavante do Brasil Central. Do total de 163 amostras de soro testadas, 5 (3,1%) foram positivas a imunofluorescencia. Todos os soros positivos procediam de individuos com sintomas clinicos da doenca. Nao foram observadas diferencas do PFE entre os Xavante e a populacao em geral sob o ponto de vista imunologico, ja que se verificou uma predominância da IgG4 entre os anticorpos nos pacientes indigenas.