Ecological processes determining the distribution dynamics of vole populations during forest succession.

Oecologia. 2018 Sep 22. doi: 10.1007/s00442-018-4261-9. [Epub ahead of print] Le Borgne H1,2, Dupuch A3,4, Fortin D3. Author information 1 Chaire de Recherche Industrielle CRSNG, Université Laval en Sylviculture et Faune. Département de Biologie, Pavillon Alexandre-Vachon, 1045 Avenue de la Médecine, Université Laval, Québec, QC, G1V 0A6, Canada. helene.le.borgne.1@gmail.com. 2 Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, 58 Rue Principale, Ripon, QC, J0V 1V0, Canada. helene.le.borgne.1@gmail.com. 3 Chaire de Recherche Industrielle CRSNG, Université Laval en Sylviculture et Faune. Département de Biologie, Pavillon Alexandre-Vachon, 1045 Avenue de la Médecine, Université Laval, Québec, QC, G1V 0A6, Canada. 4 Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, 58 Rue Principale, Ripon, QC, J0V 1V0, Canada. Abstract The size and distribution of animal populations may vary drastically over time following a disturbance event. While both competition and predation can control the size of animal populations, changes in the relative importance of these two density-dependent processes remain poorly documented during ecological succession. Here, we combined habitat selection and optimal foraging theory to identify the processes that can explain the increase in red-backed voles (Myodes gapperi) during post-logging forest succession in boreal ecosystems. Specifically, we assessed the extent to which changes in intra- and interspecific competition and in predation risk can explain variation in abundance and distribution of voles during post-harvest forest succession. We estimated the abundances of the red-backed vole and of its main competitor, the deer mouse (Peromyscus maniculatus), in adjacent pairs of logged (5-66 years old) forest stands and uncut stands (> 120 years old). We found that voles increased their preference for uncut stands with increasing conspecific density. Foraging experiments revealed that in early-seral forest stands, voles increased their feeding effort in the presence of deer mice, particularly in safer food patches. This behaviour is expected from foraging theory when interspecific competitors increase predation risk. Apparent competition would thus limit the density of red-backed voles, and changes in the relative strength of this process during forest succession would control patterns of distribution and abundance of the species. KEYWORDS: Competition; Forest succession; Habitat selection; Logging; Predation PMID: 30244315 DOI: 10.1007/s00442-018-4261-9