Abstract
Conspecific individuals often exhibit behavioral differences that influence susceptibility to predation. Yet, how such trait differences scale to affect prey population regulation and community structure remains unclear. We used an 8 day field mesocosm experiment to explore the effects of intraspecific prey behavioral trait variation on survival in an herbivorous insect community. We further manipulated spider predator composition to test for top-down context-dependence of behavioral effects. Insect prey behavioral trait variance influenced survival through both direct (i.e., variation among conspecifics) and indirect (i.e., variation among heterospecifics) mechanisms. The behavioral variance of two prey species, Philaenus and Orchelimum, directly reduced their survival, though for Philaenus, this direct negative effect only occurred in the presence of a single spider predator species. In contrast, the survival of Scudderia was enhanced by the behavioral trait variance of the surrounding insect community, an indirect positive effect. Taken together, these results emphasize the importance of accounting for intraspecific variation in community ecology, demonstrating novel pathways by which individual-level behavioral differences scale to alter population and community level patterns.
Highlights
The importance of prey traits for predatory interactions spans multiple biological scales.For example, predators exert selection on prey populations by preferentially consuming individuals with certain trait values [1,2,3,4,5,6], and modify community structure by disproportionally consuming one prey species over another [7]
We took advantage of naturally occurring boldness variation within and across prey populations and manipulated predator species composition to test for context-dependence of behavioral effects. Our study reveals both direct and indirect effects of prey boldness variance, with some effects occurring only under certain spider predator species compositions. These findings demonstrate new pathways by which behavioral trait variation within populations, often overlooked within the field of community ecology [26,27,28], could scale to regulate community assembly and food web dynamics
While Philaenus and Orchelimum boldness trait variance reduced their probability of survival, we found no evidence for direct effects in the other two prey species
Summary
Predators exert selection on prey populations by preferentially consuming individuals with certain trait values [1,2,3,4,5,6], and modify community structure by disproportionally consuming one prey species over another [7]. This latter effect is often ascribed to mean, species-level trait differences [8,9,10]. We used a field experiment to examine the effects of insect prey behavioral trait means and behavioral trait variances on the community-structuring effects of their predators (spiders)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
