title: Predicted impact of barriers to migration on the Serengeti wildebeest population.
abstract: The Serengeti wildebeest migration is a rare and spectacular example of a once-common biological phenomenon. A proposed road project threatens to bisect the Serengeti ecosystem and its integrity. The precautionary principle dictates that we consider the possible consequences of a road completely disrupting the migration. We used an existing spatially-explicit simulation model of wildebeest movement and population dynamics to explore how placing a barrier to migration across the proposed route (thus creating two disjoint but mobile subpopulations) might affect the long-term size of the wildebeest population. Our simulation results suggest that a barrier to migration--even without causing habitat loss--could cause the wildebeest population to decline by about a third. The driver of this decline is the effect of habitat fragmentation (even without habitat loss) on the ability of wildebeest to effectively track temporal shifts in high-quality forage resources across the landscape. Given the important role of the wildebeest migration for a number of key ecological processes, these findings have potentially important ramifications for ecosystem biodiversity, structure, and function in the Serengeti.
authors.affiliation: Division of Biology, University of Missouri, Columbia, Missouri, United States of America. holdor@missouri.edu
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Holdo
authors.forename: John M
authors.initials: JM
authors.lastname: Fryxell
authors.forename: Anthony R E
authors.initials: AR
authors.lastname: Sinclair
authors.forename: Andrew
authors.initials: A
authors.lastname: Dobson
authors.forename: Robert D
authors.initials: RD
authors.lastname: Holt
mesh_terms: D025041:Animal Migration; D000818:Animals; D003198:Computer Simulation; D017753:Ecosystem; D007630:Kenya; D011157:Population Dynamics; D012418:Ruminants / Q000502:physiology*; D013636:Tanzania