Rights statement: This is the peer reviewed version of the following article: Leivesley, J. A., Bussière, L. F., Pemberton, J. M., Pilkington, J. G., Wilson, K. and Hayward, A. D. (2019), Survival costs of reproduction are mediated by parasite infection in wild Soay sheep. Ecology Letters. doi: 10.1111/ele.13275 which has been published in final form at https://onlinelibrary.wiley.com/doi/full/10.1111/ele.13275 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Accepted author manuscript, 1.26 MB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
| <mark>Journal publication date</mark> | 1/08/2019 |
|---|---|
| <mark>Journal</mark> | Ecology Letters |
| Issue number | 8 |
| Volume | 22 |
| Number of pages | 11 |
| Pages (from-to) | 1203-1213 |
| Publication Status | Published |
| Early online date | 20/05/19 |
| <mark>Original language</mark> | English |
A trade-off between current and future fitness potentially explains variation in life-history strategies. A proposed mechanism behind this is parasite-mediated reproductive costs: individuals that allocate more resources to reproduction have fewer to allocate to defence against parasites, reducing future fitness. We examined how reproduction influenced faecal egg counts (FEC) of strongyle nematodes using data collected between 1989 and 2008 from a wild population of Soay sheep in the St. Kilda archipelago, Scotland (741 individuals). Increased reproduction was associated with increased FEC during the lambing season: females that gave birth, and particularly those that weaned a lamb, had higher FEC than females that failed to reproduce. Structural equation modelling revealed future reproductive costs: a positive effect of reproduction on spring FEC and a negative effect on summer body weight were negatively associated with overwinter survival. Overall, we provide evidence that parasite resistance and body weight are important mediators of survival costs of reproduction.