Wildebeest in the Serengeti are beaten to the forage by faster-migrating zebras. Credit: Lynne Smit

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An eight-year long survey of animal behavior in Serengeti National Park in Tanzania shows that competition over food pushes migrating zebras traversing the park ahead of the bigger wildebeest in grazing.

The 200,000 zebras rush to satisfy their large vegetation demand before the 1.3 million wildebeest population consumes it all. The removal of taller plants by these larger animals makes way for the population of 400,000 gazelles to reach flowering plants, and later also allows them to feed on new vegetation.

In their study, published in Science, the researchers from Wake Forest University, in North Carolina, United States, used data from a camera-trap survey, GPS-collared herbivores, and fecal DNA to analyse the timing, arrival order, and interactions among the animals in the park.

The findings show a balance between helpful and competitive forces that drive these migratory grazers’ movement and foraging behaviours. Lead researcher, Michael Anderson, said that the interactions among migratory species during the migration and landscape scale analyses of the process have been understudied.

“Our study provides a glimpse of what terrestrial ecosystems across Australia, Eurasia, and the Americas, might have looked like when communities of large herbivorous mammals roamed freely across these continents,” Anderson told Nature Africa.

The researchers say their work offers insights to conservationists on how to manage migratory herbivore populations, especially as they face future threats due to ecosystem degradation and human-induced climate change.