Grazing Succession

node · earth · Serengeti–Mara ecosystem

The proposed ordering of migrant grazers by body size, set out by Bell in 1971: zebra first, wildebeest roughly eight weeks later, Thomson's gazelle roughly eight weeks after that, each species opening up forage for the next. GPS-collar, dietary and camera-trap data published in Science in 2024 only partly upheld it. Zebra and wildebeest travelled much closer together than predicted, with competition rather than facilitation pushing zebra ahead; gazelle did trail the large migrants by about three weeks, consistent with facilitation but over a far shorter lag than Bell described. The textbook version is a simplification of a push–pull dynamic.