Crossing the western Altiplano: The ecological context of Tiwanaku migrations

Publication date: January 2020

Source: Journal of Archaeological Science, Volume 113

Author(s): Benjamin Vining, Patrick Ryan Williams

Abstract

Mobility and migration are critical processes that influence cultural and socio-economic development, and have lasting effects on demographic and ecological arrangements. However, these are ephemeral behaviors which are difficult to reconstruct archaeologically. Here, we employ geospatial approaches to reconstruct mobility corridors likely used by Tiwanaku migrants during the Andean Middle Horizon, ca. AD 500–1000. Prehispanic mobility relied on caravans of Andean camelids. We reconstruct probable mobility corridors while comparing cost- and permeability-based modeling approaches. We further use remote sensing to examine how modern ecological dynamics relate to modeled mobility corridors. Imagery from the Landsat family of multispectral satellites is used to document the response of green vegetation to seasonal and interannual moisture variability. We find that there is a statistically significant increase in the amount of perennially-green vegetation land cover along the corridor linking Tiwanaku with its principal colonial enclaves on the Pacific coast. Such perennially-green vegetation provides a critical resource for prehispanic caravans. The data indicate a relationship between high volumes of migration and enhanced vegetation. We explore whether Tiwanaku migration routes were established in part on the basis of this resource, or if modern land cover reflects an anthropogenic legacy.