Isotopic investigation of pre-Hispanic macaw breeding in Northwest Mexico

The pre-Hispanic settlement of Paquimé (ca. 1200-1450 AD) lay outside of urban Mesoamerica in arid northern Chihuahua, Mexico, yet the excavated remains of 322 scarlet macaws, tropical parrots whose northernmost habitat is 500 km to the south, suggest that Paquimé had relationships with distant communities. Here, carbon and oxygen stable isotope analysis of 30 macaw bones determines whether the Paquimeños actively bred these parrots or traded with Mesoamerican groups to obtain the birds. The δ¹³C values indicate that the macaws ate a diet of C₄ plants, foods that were unavailable to wild macaws. In addition, δ¹⁸O data suggest that the majority of the macaws spent their entire lives at Paquimé. We conclude that the ancient Paquimeños were in fact breeding scarlet macaws, although one bone with δ¹⁸O values outside the local range suggests that the breeders also maintained exchange ties with the source areas of the birds. By confirming that Paquimeños implemented a system of local macaw reproduction outside the Mesoamerican region itself, this analysis provides new evidence about the economic and ideological interdependence of pre-Hispanic societies in the Americas. It is also suggestive of the pre-industrial capabilities of humans to extend the natural ranges of animal species.