Authors: Lisa A Taylor David L Clark Kevin J McGraw
Publish Date: 2010/12/22
Volume: 65, Issue: 5, Pages: 1133-1146
Abstract
In many animals conspicuous coloration functions as a quality signal Indicator models predict that such colors should be variable and condition dependent In Habronattus pyrrithrix jumping spiders females are inconspicuously colored while males display brilliant red faces green legs and white pedipalps during courtship We tested the predictions of the indicator model in a field study and found that male body condition was positively correlated with the size hue and red chroma of a male’s facial patch and negatively correlated with the brightness of his green legs These traits were more condition dependent than nondisplay colors We then tested a dietary mechanism for condition dependence using two experiments To understand how juvenile diet affects the development of coloration we reared juvenile spiders on high and lowquality diets and measured coloration at maturity To understand how adult diet affects the maintenance of coloration we fed wildcaught adults with high or lowquality diets and compared their coloration after 45 days In the first experiment males fed highquality diet had redder faces suggesting that condition dependence is mediated by juvenile diet In the second experiment red coloration did not differ between treatments suggesting that adult diet is not important for maintaining the color after it is produced at maturity Diet had no effect on green coloration in either experiment Our results show different degrees of condition dependence for male display colors Because red is dependent on juvenile diet it may signal health or foraging ability We discuss evidence that green coloration is age dependent and alternatives to indicator models for colorful displays in jumping spidersWe thank C Torres L Hall G Lewis L Ramirez and J Grieco for the assistance in the field and lab J Alcock M Butler C Johnson M Meadows M Rowe R Rutowski and M Toomey provided helpful feedback throughout the study J Alcock R Rutowski and four anonymous reviewers provided useful comments on previous versions of the manuscript We thank M and C Schnepf for the permission to collect spiders on their property This work was supported by an Animal Behavior Society student research grant a Sigma Xi GrantinAid of Research and a National Science Foundation Graduate Research Fellowship to LAT
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