Predators reduce extinction risk in noisy metapopulations

• Published in: PloS one Vol. 5; no. 7; p. e11635
• Main Authors: Bull, James C, Bonsall, Michael B
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21.07.2010; Public Library of Science (PLoS)
• Subjects: Animal behavior; Animals; Background noise; Beans; Biodiversity conservation; Biogeography; Callosobruchus maculatus; Coleoptera - growth & development; Coleoptera - physiology; Competition; Dispersal; Dynamic models; Dynamics; Ecology; Ecology/Population Ecology; Ecology/Spatial and Landscape Ecology; Endangered & extinct species; Environmental conditions; Extinction; Extinction (Biology); Fabaceae - growth & development; Fabaceae - parasitology; Host-Parasite Interactions - physiology; Immigration; Insects; Landscape; Laws, regulations and rules; Local population; Metapopulations; Models, Theoretical; Noise; Parasitism; Parasitoids; Population; Population biology; Population Dynamics; Population regulation; Predators; Spatial analysis; Species extinction; Time series; Weevils - growth & development; Weevils - physiology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0011635

Spatial structure across fragmented landscapes can enhance regional population persistence by promoting local "rescue effects." In small, vulnerable populations, where chance or random events between individuals may have disproportionately large effects on species interactions, such local processes are particularly important. However, existing theory often only describes the dynamics of metapopulations at regional scales, neglecting the role of multispecies population dynamics within habitat patches. By coupling analysis across spatial scales we quantified the interaction between local scale population regulation, regional dispersal and noise processes in the dynamics of experimental host-parasitoid metapopulations. We find that increasing community complexity increases negative correlation between local population dynamics. A potential mechanism underpinning this finding was explored using a simple population dynamic model. Our results suggest a paradox: parasitism, whilst clearly damaging to hosts at the individual level, reduces extinction risk at the population level.