The population of large animals in the Gorongosa National Park collapsed during the Mozambican civil war (1977–92), and led to encroachment of the invasive shrub Mimosa pigra. Writing in Nature Ecology & Evolution, Guyton et al.1 report that Gorongosa’s repopulation with large herbivores has reduced the abundance of mimosa to pre-war levels.
By analysing faecal samples from Gorongosa’s five main ruminant herbivores, including waterbuck (Kobus ellipsiprymnus; pictured), the authors found that mimosa was the main component of the diets of these species in 2013–18. They also found that the shrub’s density and biomass were greater in fenced enclosures that excluded herbivores than in unfenced areas.
The authors therefore conclude that the burgeoning populations of native large herbivores are consuming mimosa, and have thereby conferred resistance to its invasion in just ten years. The findings suggest that rewilding is a potentially useful strategy for reversing a common form of environmental degradation in Africa’s protected areas.
Nature 577, 476 (2020)