Measuring Hunter-Gatherer Mobility
Great to see this paper on the movement ecology of Hadza hunter-gatherers finally out in Nature Human Behavior. Lead author Brian Wood began the data collection when he was a post-doc with me at Stanford over a decade ago. The analysis is based on over 23,000 person-hours of observation and it this really provides a sense of the sort of time scales that are required for rigorous scientific anthropology. This was a monumental data-collection and data-analysis effort. Brian has really set the standard for movement ecology here.
In this paper, we show that Hadza men average about eight miles of travel per day and women average about five miles per day. Note that this is more than three times greater than the distance traveled by people in a global sample of smartphone users in middle- and high-income countries. Men's travel is more sinuous and more likely to be undertaken alone than women's travel. There are interesting life-cycle findings as well. For example, gender differences appear quite early in life. Furthermore, consistent with the important role they play in economically subsidizing their adult daughters (and grandchildren), elder women largely continue their typical travel well into their sixties, while men's travel declines quite steeply at this age.
The always great Josie Garthwaite wrote a nice news piece for the Stanford Earth to accompany publication of the paper.
As I said, Brian really innovated on the measurement of human mobility for this work. This innovation has been recognized by his being invited to be a co-PI on PIPP Theme 1, where he was able to provide expertise on their core themes of monitoring human movements and at-risk communities for disease transmission and spread and data-intensive machine learning and modeling for pandemic preparedness.
Citation
Wood, B.M., J.A. Harris, D.A. Raichlen, H. Pontzer, K. Sayre, A. Sancilio, C. Berbesque, A.N. Crittenden, A. Mabulla, R. McElreath, E. Cashdan, and J.H. Jones. 2021. Gendered movement ecology and landscape use in Hadza hunter-gatherers. Nature Human Behaviour. (doi:10.1038/s41562-020-01002-7)
