title: Sex differences in relationships between habitat use and reproductive performance in Soay sheep (Ovis aries).
abstract: The role of habitat use in generating individual variation in fitness has rarely been examined empirically in natural populations of long-lived mammals, particularly for both sexes simultaneously. This is the case despite the increase in studies attempting to understand evolutionary change in such populations. Using data from the St. Kilda Soay sheep population, we quantified the association between lifetime reproductive performance (lifetime breeding and reproductive success) and the proportion of the home range covered by a key grass species, H. lanatus, for 490 females and 304 males. Increased H. lanatus cover was associated only with increased female lifetime reproductive success, but increased lifetime breeding success for both sexes, arising through increased male longevity and increased female fecundity. This work suggests that improved understanding of the causes and consequences of fitness differences will likely require us to better account for habitat-derived individual variation, and to do so for the sexes appropriately.
authors.affiliation: Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK.
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Regan
authors.affiliation: Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK.
authors.forename: Jill G
authors.initials: JG
authors.lastname: Pilkington
authors.affiliation: Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Pemberton
authors.affiliation: Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, Silwood Park, Ascot, Berkshire, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Crawley
keywords: Fitness; Scotland; Soay sheep; St Kilda; grassland; habitat use; heathland; home range; lifetime reproductive success (LRS)