Under the guidance of Dr. Diane Gifford-Gonzalez, Anneke Janzen will use domestic animal teeth excavated from early pastoralist sites in Kenya to shed light on the earliest pastoralists in East Africa. Specifically, she will apply stable isotope and mortality profile analysis to explore ancient herding practices and assess whether these differ from recent and present-day herders' practices in the region. Based mainly on domestic cattle, sheep, and goats, African pastoralism is broadly sustainable in lands too dry to farm. It emerged c. 7500 years ago in the then-green Sahara, and recent analyses have demonstrated dairying then. As the Sahara dried, herding groups moved south into western and eastern Africa, entering far northern Kenya c. 5000 years ago and the highly productive savannas of southern Kenya c. 3300 years ago.
Studies in Europe and South Africa demonstrated that analysis of stable isotopes in livestock teeth from archaeological sites could inform on ancient pastoralists' mobility and animal husbandry practices (age of weaning, movement of herds). Isotopes testify to what plant communities fed an animal over its lifetime (stable carbon and nitrogen isotopes), whether these circumstances changed over its lifespan, and whether it moved far enough from the locale of its youth to end up on a different geological substrate (strontium isotopes). Mortality profile analysis complements this by constructing a picture of the modal ages at which different domestic species were slaughtered, data best derived from dentitions.
Little detail is yet known of ancient Kenyan herding practices, which modern cases suggest could be quite flexible, according to environmental circumstances and herders' production goals (meat vs. dairy vs. combinations). Ms. Janzen will investigate: (1) whether early herders in the steep-sided and narrow Rift Valley pursued mobility similar to recent pastoralists, who seasonally shifted their herds from the valley floor to high alpine meadows, or whether, in those less populous and moister past times, they remained in the lowlands year round. (2) How far livestock moved during their lifetimes, not just seasonally, but over longer time spans and distances. This can elucidate interactions among herder communities, for whom livestock exchange, gifts, and theft can play a major economic and social role. (3) Economic relations between the incoming herders and the hunter-gatherers who had lived in the region for millennia. Historically, hunter-gatherers symbiotic with pastoralists ultimately start to convert from pure foraging to a mix of foraging and some livestock, usually goats and sheep. Isotopic analysis can show whether domesticates in forager sites were locally grown or brought in from elsewhere.
The intellectual merit of this project lies in its contribution to pastoralist's history as part of the region's integrated farming, foraging, and herding economies, emergent well before the colonial era, and documentation of land use through East Africa's long-term history. Its broader impacts include documenting long-term variations in pastoralism, which may help planners assessing future alternatives in today's rapidly desiccating region. It gives professional training to Ms. Janzen, plus affording Masters-level Kenyan archaeology students a hands-on introduction to cutting-edge methods to zooarchaeology.
