Rabbit bone stable isotope values distinguish desert ecoregions of North America: Data from the archaeological sites of Pueblo Grande, La Ferreria, and La Quemada

Abstract

This study demonstrates the ability of light element stable isotope data from leporid (rabbit and jackrabbit) bone samples to reflect paleoenvironments at archaeological settlements in arid and semi-arid environments. A sample of 214 leporid bones recovered from the pre-Hispanic archaeological sites of Pueblo Grande (Arizona, USA), La Ferreria (Durango, Mexico) and La Quemada (Zacatecas, Mexico) are analyzed for stable isotope values of oxygen (δ18Ocarbonate) and carbon (δ13Ccarbonate) in bone mineral carbonate, and stable isotope values of nitrogen (δ15Ncollagen) and carbon (δ13Ccollagen) in bone collagen. These site locations represent terrestrial ecoregions of the Sonoran Desert, the Chihuahuan Desert, and the Central Mexican Matorral, respectively. Stable isotope values are used to test predicted differences generated from known environmental parameters at these locations based on 50-year averages of modern climatic data. The resulting δ18Ocarbonate values match expectations based on differences in mean annual precipitation; δ15Ncollagen results confirm expectations based on relative temperature differences; and δ13Ccarbonate and δ13Ccollagen results support predictions based on the relative abundance of grassland environments at each location. Multivariate analyses of the four stable isotope variables together demonstrate the ability of leporid bones to distinguish between desert ecoregions and indicate the utility of including stable isotope analyses of bones from small mammals to characterize environmental conditions of past terrestrial ecoregions.