Quantifying multi-scale pastoral mobility: Developing a metrics system and using GPS-Tracking data for evaluation

Mobility appears to be in decline in modern pastoralism, but measurement of mobility has been ambiguous. This paper develops a metrics system to evaluate multi-scale pastoral mobility, and uses continuous, frequent, cross-season GPS-tracking data to investigate movement patterns in five pastoral communities in southern Ethiopia. The metrics system includes both broad-scale indicators such as home range and number of camps, and fine-scale indicators such as herding loop length, daily maximum distance from camp, and angular distribution of observed cow locations. The findings suggest pastoral mobility patterns are highly heterogeneous, and there are clear trade-offs among different mobility indicators in pastoralists' herding strategies. In contrast to conventional understanding that mobility declines when pastoralists settle down, I find evidence of sedentarized pastoralists engaging in more rigorous fine-scale movement than those who keep practicing camp relocation. Thus, pastoral mobility cannot be generalized according to any single indicator, and comprehensive evaluation is necessary to advance our understanding of pastoral mobility as a complex strategy to manage herds in the arid and semi-arid environments.