Large herbivore migrations move biomass and nutrients across landscapes, shaping soils, plants, and food webs. Research by George B. Schaller at the Wildlife Conservation Society documented how wildebeest and other ungulates concentrate organic matter through dung, urine and carcasses during seasonal movements, creating spatially heterogeneous resource hotspots. These processes are central to nutrient redistribution because animals act as mobile vectors that transfer nitrogen, phosphorus and carbon from one patch to another.
Mechanisms of transfer
Migrating herds redistribute nutrients primarily via excretion, carcass deposition, and physical disturbance of vegetation and soil. Excretion adds labile nutrients that accelerate microbial activity and plant uptake. Carcasses supply pulses of organic matter that sustain scavengers and enrich soils over longer timescales. Trampling and selective grazing change litter accumulation and root dynamics, altering decomposition rates. Tony Sinclair at the University of British Columbia and collaborators have emphasized how these mechanisms operate at different spatial and temporal scales, with short-term hotspots around water and calving sites and long-term legacies in migratory corridors.
Ecological and territorial consequences
Nutrient redistribution influences primary productivity, plant species composition, and animal community structure. Recipient areas often show increased grass growth and higher herbivore densities, which in turn affect predators and seed dispersal networks. Conversely, source areas may experience reduced nutrient stocks. Human land use and infrastructure modulate these outcomes: fences, roads and land conversion break migration corridors, reducing connectivity and trapping nutrients in small areas. This fragmentation can lead to soil degradation, reduced forage quality and altered watershed nutrient export. Cultural practices such as pastoralist seasonal movements in East Africa historically complemented ungulate migrations, creating shared patterns of nutrient use and regeneration that are sensitive to modern policy changes.
Scientific observations by Schaller and field syntheses by Sinclair illustrate that the effects depend on herd size, migration distance, and ecosystem type. In prairie, savanna and tundra systems alike, migrations can couple distant patches, linking alpine or wetland nutrient production to lowland food webs. Management implications include conserving corridors to maintain ecosystem services and recognizing that losing migrations often translates into localized nutrient depletion and diminished resilience.