Environmental conditions influence red grouse ornamentation at a population level

Theory suggests that condition-dependent sexual displays should be more weakly expressed under adverse conditions than under more favourable ones. Here, we tested this hypothesis in wild red grouse Lagopus lagopus scoticus using a data set of nearly 1500 individuals from nine populations over 8 year...

Full description

Bibliographic Details
Published in:Biological Journal of the Linnean Society
Main Authors: Vergara, Pablo, Redpath, Steve, Martínez-Padilla, Jesús, Mougeot, François
Other Authors: Natural Environment Research Council (UK), European Commission
Format: Article in Journal/Newspaper
Language:unknown
Published: Linnean Society of London 2012
Subjects:
NAO-index
Condition-dependence
Nematode infection
Sexual selection
Social context
Trichostrongylus tenuis
Population density
Ner
North Atlantic
North Atlantic oscillation
Online Access:http://hdl.handle.net/10261/143313
https://doi.org/10.1111/j.1095-8312.2012.01974.x
https://doi.org/10.13039/501100000270
https://doi.org/10.13039/501100000780
Description
Summary:Theory suggests that condition-dependent sexual displays should be more weakly expressed under adverse conditions than under more favourable ones. Here, we tested this hypothesis in wild red grouse Lagopus lagopus scoticus using a data set of nearly 1500 individuals from nine populations over 8 years, covering varying environmental conditions. We analysed whether male and female ornament expression (i.e. comb size) in a given site and year varied with various indices of environmental conditions: population density, Trichostrongylus tenuis nematode infection at the population level, and climate conditions [measured as winter North Atlantic oscillation (NAO) index]. We found that average comb size in males, but not in females, negatively correlated with population density, parasite infection levels, and winter NAO index. Furthermore, the coefficient of variation (CV) of comb size was higher in females than in males. CVs in both males and females were not clearly associated with the studied environmental variables. Our results support the idea that the expression of condition-dependent sexual traits should be lower under more stressful environmental conditions, but only in males. We discuss the potential reasons behind the effect of environmental conditions on secondary sexual traits, and why these effects differ between sexes. P.V. was supported by an IntraEuropean Marie Curie Fellowship (European Union Seventh Framework Programme, FP7/2007–2013, grant agreement no. 252499). F.M. was supported by an NERC advanced fellowship. We held all the necessary UK Home Office licences for conducting these procedures (PPL80/1437 and PPL60/3824). This study was funded by Natural Environment Research Council (grants NER A-1/S/1999/00074, NE/D000602/1 and NE/D014352/1). Peer Reviewed

Similar Items