Loss of seasonal ranges reshapes transhumant adaptive capacity: Thirty-five years at the US Sheep Experiment Station

Transhumance is a form of extensive livestock production that involves seasonal movements among ecological zones or landscape types. Rangeland-based transhumance constitutes an important social and economic relationship to nature in many regions of the world, including across the Western US. However, social and ecological drivers of change are reshaping transhumant practices, and managers must adapt to increased demands for public rangeland use. Specifically, concerns for wildlife conservation have led to reduced access to seasonal public lands grazing for western US livestock producers. To understand how managers adapt to loss of grazing areas (called “seasonal ranges”) we create agroecological calendars from manager records spanning 35 years (1986–2021) at the US Sheep Experiment Station in Idaho and Montana, US. The calendars illustrate how a loss of winter and summer ranges after 2013 coincided with shifts in the operation’s adaptive strategies, leading to more grazing of fall crop residue and purchased winter feed, and reducing flexibility to move livestock to cope with variable forage conditions. These changes shifted the job duties and experiences of farm workers and managers, and raised several new questions related to sheep production and vegetation management outcomes that merit future research. Transhumant system transformation has implications for human relationships with nature, rural communities, sheep genetics, production, and vegetation communities. For livestock operations that rely on government-managed lands to sustain transhumant traditions, innovative forms of collaboration and social adaptation that help secure access to seasonal ranges will be as important as technological innovations to address biodiversity conservation, climate change adaptation, and food system sustainability issues that are reshaping access to grazing lands.