Apex consumer ecology
Ecologists conventionally discuss apex predators: those at the top of their food chains. However, the concept also stretches to apex herbivores: animals large enough to escape predation and control their ecosystem, also known as megaherbivores. The EU-funded HOT-SPOT (Resource hotspots and the role of apex predators in terrestrial ecosystems) project studied both types of apex consumers. The research documented African savannahs plus Swedish boreal (coniferous) and nemoral (mixed-deciduous) forests, using a combination of observational and experimental methods. Results included new insights about the ways in which apex consumers influence ecosystem functions. For example, megaherbivores modify the predation risk associated with the effects of apex carnivores on lower tropic levels. The reason was that megaherbivores are not affected by predation risk. The team also showed various ways in which megaherbivores – specifically white rhino and African elephants – shape the structure of savannahs. The work was significant considering the poaching threats to both species. Other outcomes included details of how Scandinavian carnivores, particularly the brown bear, influence the behaviour of herbivores. Researchers also examined whether such changes affect lower tropic levels. In general, the work contributed understanding about the consequences of losing apex consumers and the effects of their reintroduction. The project also successfully developed the careers of its researchers.
Keywords
Resource hotspots, apex consumers, HOT-SPOT, predators, herbivores, effects
