Susan Tanner

Evaluating indices of traditional ecological knowledge: a methodological contribution

BackgroundNew quantitative methods to collect and analyze data have produced novel findings in ethnobiology. A common application of quantitative methods in ethnobiology is to assess the traditional ecological knowledge of individuals. Few studies have addressed reliability of indices of traditional ecological knowledge constructed with different quantitative methods.MethodsWe assessed the associations among eight indices of traditional ecological knowledge from data collected from 650 native Amazonians. We computed Spearman correlations, Chronbachs alpha, and principal components factor analysis for the eight indices.ResultsWe found that indices derived from different raw data were weakly correlated (rho<0.5), whereas indices derived from the same raw data were highly correlated (rho>0.5; p < 0.001). We also found a relatively high internal consistency across data from the eight indices (Chronbachs alpha = 0.78). Last, results from a principal components factor analysis of the eight indices suggest that the eight indices were positively related, although the association was low when considering only the first factor.ConclusionA possible explanation for the relatively low correlation between indices derived from different raw data, but relatively high internal consistency of the eight indices is that the methods capture different aspects of an individuals traditional ecological knowledge. To develop a reliable measure of traditional ecological knowledge, researchers should collect raw data using a variety of methods and then generate an aggregated measure that contains data from the various components of traditional ecological knowledge. Failure to do this will hinder cross-cultural comparisons.

Human Body-mass Index (Weight in kg/stature in m2) as a Useful Proxy to Assess the Relation between Income and Wildlife Consumption in Poor Rural Societies

Abstract.There is growing interest in assessing how income influences the consumption of wildlife in poor rural areas of developing nations. The interest stems from the possibility of using income to contribute to the conservation of wildlife. Though promising, efforts have been hampered by the difficulty of obtaining accurate measures of income. We propose using human body-mass index (BMI: weight in kilograms/physical stature in m2), an indicator of short-term nutritional status, as a proxy variable for monetary income to estimate income elasticities of wildlife consumption (income elasticity: percent change in wildlife consumption/one-percent change income). The advantages of BMI over monetary income include a positive association with monetary income, ease of measurement, and absence of zero values. The assessment procedure was tested among Tsimane’ Amerindians, a society of foragers and farmers in the Bolivian Amazon. The population over 15xa0years of age (350 men and 322 women) in 13 villages was surveyed for five consecutive quarters (August 2002–November 2003). Income elasticities of wildlife consumption using BMI as a proxy for income ranged from −0.84 to −1.20. The estimates suggest that wildlife is a food item whose consumption declines with increasing income. Estimates of income elasticity of wildlife consumption using conventional indices of monetary income are negative, but lower and indistinguishable from zero owing to classical measurement errors of monetary income. The use of BMI to estimate income elasticities of wildlife consumption is promising, but requires further validation in different settings.