1Anthropology, Grinnell College, 2Nutrition Laboratory, Conservation Ecology Center, National Zoological Park, Smithsonian Institution
Friday All day, Plaza Level
As part of our investigation of yellow baboon nutrition, we examined mineral content of common food sources – an area little studied in primate nutritional ecology. Consumption and nutrient content data for the Mchelelo troop (n=75) are based upon January 1988-October 1992 observational data (875 days; 4893 hourly scans) and chemical assays of 110 samples representing 56 flora species (31 families). We assayed calcium, phosphorous, potassium, magnesium, iron, zinc, and manganese content for each sample using AA or UV spectrometry. Tana baboon foods averaged (dry matter basis): calcium=0.335% (SD=0.31); phosphorous=0.233% (SD=0.10); potassium=1.532% (SD=0.53); magnesium=0.215% (SD=0.14); iron=0.034% (SD=0.05); zinc=0.002% (SD=0.001); manganese=0.011% (SD=0.06). The data were transformed using the following formula to determine dietary mineral concentration: mineral concentration (mg/kg) = sum over all species of [(Average mg/kg mineral for a given species * % of observations for that species)/100]. Tana baboons’ dietary mineral concentrations exceed NRC recommendations for iron, manganese, magnesium, and potassium; but are below recommendations for calcium, phosphorous, and zinc. The top three foods’ contributed more to dietary minerals than would be expected from the relative consumption of these foods (X2=53.475, df=6, p<0.001), and the top 10 foods account for up to 95% (e.g., manganese) of some of the dietary minerals. A few species are responsible for large proportions of particular minerals (Salvadora persica: iron, Dobera glabra: manganese, Hyphaene compressa: zinc.) Our data indicate that a limited number of species ingested by Tana baboons account for most dietary minerals. Mineral content may be a factor in primate food choice.
This project was supported, in part, by the Grinnell College Dean’s Office and Committee for Support of Faculty Scholarship.