title: Environmental factors influence both abundance and genetic diversity in a widespread bird species.
abstract: Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations.
authors.affiliation: State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University Guangzhou, 510275, China ; Evolutionary Ecology Group and Computational and Molecular Population Genetics, Institute of Evolution and Ecology, University Bern Balzerstrasse 6, Bern, CH-3012, Switzerland.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Centre for Ornithology, University of Birmingham Edgbaston, Birmingham, BT15 2TT, UK.
authors.forename: Simone
authors.initials: S
authors.lastname: Webber
authors.affiliation: School of Applied Sciences, Bournemouth University, Talbot Campus Poole, Dorset, BH12 5BB, UK.
authors.forename: Katharine
authors.initials: K
authors.lastname: Bowgen
authors.affiliation: Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen PO Box 11103, Groningen, 9700 CC, The Netherlands.
authors.forename: Lucie
authors.initials: L
authors.lastname: Schmaltz
authors.affiliation: 10 Springhill Close, London, SE5 8AJ, UK.
authors.forename: Katharine
authors.initials: K
authors.lastname: Bradley
authors.affiliation: Section of Animal Ecology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University Uppsala, SE-75236, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Halvarsson
authors.affiliation: Section of Animal Ecology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University Uppsala, SE-75236, Sweden ; Department of Biology, College of Sciences, University of Hail Hail, PO 2440, Saudi Arabia.
authors.forename: Mohanad
authors.initials: M
authors.lastname: Abdelgadir
authors.affiliation: Department of Ecology, Swedish University of Agricultural Sciences Uppsala, Sweden ; Anthropological Institute and Museum, University Zürich Zürich, 8057, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Griesser
keywords: Animals; conservation; molecular ecology; population genetics