Geochemical research reveals dietary variability in modern pastoralists

The pastoralist lifestyle is often depicted as an unchanging dietary reliance on herd animals and mobility. This is particularly the case in eastern Africa, where a dedicated focus on herds, meat and dairy, alongside extreme mobility, is seen as the perfect adaptation to aridity, seasonal climate variability, and political unpredictability.

Nevertheless, a growing body of research has identified other factors underlying the adaptability of pastoralists: interconnected communities and highly dynamic subsistence strategies. Understanding these adaptations is critical in eastern Africa, where climate change is leading to increased annual extremes and where pastoral mobility and connectivity is threatened by land use and socioeconomic changes.

In this study, published in Current Anthropology, researchers from MPI-GEA, the University of York, the International Livestock Research Institute and the Turkana Basin Institute, among others, used hair isotope analysis within a framework of close, long-term collaboration with local communities to study how diet varied among Turkana communities through the wet and dry seasons.

“Our results demonstrate that herders rely on herd animals seasonally rather than exclusively, demonstrating more dynamic livelihoods than is often presumed, including in the humanitarian and development spheres,” says Samuel Derbyshire, co-lead author of the study.

Isotope analysis of human tissues has been applied in archaeological, medical, and nutritional studies to explore changes in an individual’s diet and how these changes are connected to climate change. However, the application of these methods within collaborative ethnographic research frameworks has been lacking, despite their ability to provide fast, direct insights into the impacts of climate change on human diet. Moreover, when isotope analysis is combined with close ethnographic collaboration, novel, culturally-specific insights into geochemical variation can be interpreted in greater detail.

“We combined questionnaires and enthnographic research with 150 hair samples to challenge assumptions about pastoralism, revealing interconnectedness within an overarching pastoral economy in eastern Africa,” says Madeleine Bleasdale, co-lead author of the study.

The researchers’ analysis also considers the impact of unpredictable rainfall, highlighting heightened milk consumption amongst herders even after a scant rainy season, and thus pastoralism’s remarkable capacity to adapt to volatile conditions.

“The study has broader implications for our understanding of contemporary pastoral societies in the face of environmental challenges,” notes supervising author Patrick Roberts. “It contributes to discussions about the resilience of drylands pastoralism and calls for a re-evaluation of development-related approaches that may oversimplify livelihoods due to outdated perspectives.”