*Note: This article first appeared in the Solutions Journal (Volume 7, Issue 5, p. 17-20).
Rangelands of the Borana Zone in southern Ethiopia supported one of the most sustainable and productive pastoral systems in East Africa until early 1980s (Cossins & Upton, 1987). This past success could largely be attributed to the indigenous rangeland management institutions which regulated both fine- and broad-scale seasonal migration activities of the Boran pastoralists (Legesse, 2000).
These institutions maintained flexible access to diverse forage resources distributed in sub-humid, semi-arid and arid environments throughout the entire Borana Zone, which ensured both rangeland sustainability and livelihood security. These institutions were also dynamic having constantly adjusted to socio-ecological changes for centuries.
In recent decades, however, three emerging issues have challenged the efficacy of rangeland management and regulation in Borana, with direct consequences to the sustainability of pastoral livelihoods and the ecological health of these grazing lands.
- First, pressures from increasing human and livestock population and declining forage resource quality and quantity have often caused pastoralists to ignore and violate indigenous rangeland management regulations (Watson, 2003).
- Second, external interventions intended to promote livelihood diversification for pastoralists have had the secondary consequence of also encouraging sedentarization.
- Third, pastoralists have been experiencing increased environmental stresses. Drought has been impacting the grazing system more frequently and severely in recent decades, and this trend is projected to intensify in the future with climate change (Funk et al., 2008).
The combination of these stressors has made the entire pastoral system in Borana more vulnerable. Recognizing this increased vulnerability and its potential consequences, a research team from Cornell University, USDA Agricultural Research Service, International Livestock Research Institute, and University of Sydney set out in 2011 to investigate the opportunities and constraints to extensive livestock herding in Borana.
The team deployed GPS collars on 60 beef cows from 20 households distributed among five study sites to investigate pastoral mobility and resource-use patterns within the Borana Zone (Figure 1 and 2). These tracking systems updated household-level herd locations every five minutes from August 2011 to August 2015 collecting a total of 10.4 million GPS coordinate observations.
These GPS tracking data were used to evaluate the overall mobility patterns exhibited by Borana pastoralists across seasons. Socio-ecological contexts and constraints differed among study sites, and pastoralists responded to these differences by employing distinct strategies to manage their herds and by developing alternative mobility approaches to cope with environmental stresses.
Pastoral mobility in Borana can be broadly summarized with three conceptual models, namely:
- a restricted herding model,
- a semi-extensive herding model, and
- an extensive herding model (see Figure 1 below).
- In the first case (Figure 1a), increased population density and sedentarization lead to the formation of several heavily-used travel corridors connecting a base camp to just a few, small, tightly-confined foraging areas. Sedentarization and conversion of communal rangelands into crop fields and fenced rangeland reserves strongly constrained the directionality and extent of herd movement and promoted concentrated utilization of rangelands throughout much of that extent. This intensive and recursive use of the same rangeland areas has the potential to promote or accelerate ecological degradation and compromise livestock productivity (Sternberg, 2012).
- The second model (Figure 1b) reflects a less confining resource situation where population densities and consequent competition for resources are lower. This model can also represent a dry season herding practice when mobility is anchored to base camp locations with ground-water wells and one or two satellite herding camps. In this case, movement between satellite camps is rare, and the herd usually return to the base came for a short period before departing again for another satellite camp. Given that mobility under this model is still quite restricted, some recursive livestock use and consequent environmental damage are difficult to avoid.
- In the third model (Figure 1c), lower population density and less restrictions on foraging area choices allow the pursuit of the extensive herding strategy which includes a base camp and many well-dispersed satellite camps. Travel routes between camps are not formalized or intensively used. Recursive use around camps is avoided by moving the herd along a different foraging orbit each day.
Our research suggests that extensive herding, as shown in the third model, allows the pastoral systems to absorb environmental disturbances such as drought and contributes to the overall resilience of these systems. Mobile livestock herding based on flexible access to rangelands in strategic locations at times of need has proven to be successful in Borana for centuries.
However, this traditional livelihood strategy has been subject to a series of socio-ecological threats, including diminishing forage and water resources and accelerating human population increases (Coppock, 2016). Consequently, per capita rangelands area is declining quite rapidly thus producing strong constraints on pastoral mobility.
New, innovative herding strategies are needed to respond to these constraints and avoid the increased prevalence of excessive herbivory and recursive trailing as illustrated in our first and second models above. Our research team is working to inform solutions to this need by conducting analyses of pastoralist decision making and livestock movement patterns in Borana using large-scale discrete choice models (Ermon et al., 2015) and testing the efficacy of dynamic Brownian bridge movement models originally developed by Kranstauber et al. (2012) for wildlife applications.
We recommend that future pastoral policy making should prioritize the maintenance and protection of the herding sector so crucial to the livelihoods of Boran pastoralists. Planning and development of crop fields and rangeland reserves should avoid impinging on the directionality options for livestock herd movement.
This kind of consideration and forethought could reduce the potential for recursive livestock use and establishment of heavily-impacted travel corridors. In cases where sedentarization is being and will be voluntarily adopted by pastoralists, policy-makers should allow pastoralists to herd livestock within a movement extent that is expansive enough to effectively distribute grazing pressure throughout the landscape. It is crucial to limit the density of settlement clusters and prevent or slow the contraction of available grazing areas to the point where heavy and recursive use of rangelands begins to occur.
At a broader spatial scale, grazing resource-sharing agreements among pastoral communities based on the principle of reciprocity need to be promoted and facilitated as a strategy to cope with drought (Kamara et al., 2005). Policies which remove impediments to these agreements would allow drought-stricken pastoralists to migrate to distant, less impacted lands and then reciprocate in turn by sharing their grazing lands with migrant herds.
These agreements would foster extensive herd movement patterns mimicking, at a very broad scale, those illustrated under our third conceptual model (Figure 3c). This increased herd mobility would lessen the stresses of excessive and recurrent herbivory on drought-impacted vegetation, allow more rapid recovery of plant vigor, and decrease mortality losses.
Combined efforts to enhance fine- and broad-scale herd mobility can help enhance pastoral system resilience and make pastoralists more prepared to cope with the challenges of overpopulated rangelands, tendencies toward sedentarization, and increases in drought stress brought on by climate change.
For those interested in learning more about our livestock mobility research in the region, please contact our corresponding author Patrick E. Clark at Pat.Clark@ars.usda.gov.
About the authors
Chuan Liao is a postdoctoral research fellow in the School of Natural Resources and Environment at the University of Michigan.
Patrick E. Clark is a range scientist at the Northwest Watershed Research Center at the USDA Agricultural Research Service.
Stephen D. DeGloria is a professor in the School of Integrative Plant Science at Cornell University.
Andrew Mude is a principal economist at International Livestock Research Institute (ILRI) based in Nairobi, Kenya.
Christopher B. Barrett is a professor in the Dyson School of Applied Economics and Management at Cornell University.
This research was funded by AustralianAid, Cornell University Atkinson Center for a Sustainable Future, and the United States Agency for International Development. We appreciate the advice and support from Wako Gobu, Nathaniel Jensen, Mohamed Shibia, Birhanu Tadesse, and Russell Toth.
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