Present address: Biodiversity and Climate Research Centre, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany.
The role of phenotypic plasticity in responses of hunted thinhorn sheep ram horn growth to changing climate conditions
Article first published online: 12 FEB 2010
© 2010 The Authors. Journal Compilation © 2010 European Society For Evolutionary Biology
Journal of Evolutionary Biology
Volume 23, Issue 4, pages 783–790, April 2010
How to Cite
LOEHR, J., CAREY, J., O’HARA, R. B. and HIK, D. S. (2010), The role of phenotypic plasticity in responses of hunted thinhorn sheep ram horn growth to changing climate conditions. Journal of Evolutionary Biology, 23: 783–790. doi: 10.1111/j.1420-9101.2010.01948.x
- Issue published online: 19 MAR 2010
- Article first published online: 12 FEB 2010
- Received 8 July 2009; accepted 6 January 2010
- climate change;
- Ovis dalli;
- phenotypic plasticity
When phenotypic change occurs over time in wildlife populations, it can be difficult to determine to what degree it is because of genetic effects or phenotypic plasticity. Here, we assess phenotypic changes over time in horn length and volume of thinhorn sheep (Ovis dalli) rams from Yukon Territory, Canada. We considered 42 years of horn growth from over 50 000 growth measurements in over 8000 individuals. We found that weather explained a large proportion of the annual fluctuation in horn growth, being particularly sensitive to spring weather. Only 2.5% of variance in horn length growth could be explained by an individual effect, and thus any genetic changes over the time period could only have had a small effect on phenotypes. Our findings allow insight into the capacity for horn morphology to react to selection pressures and demonstrate the overall importance of climate in determining growth.