Juvenile social experience generates differences in behavioral variation but not averages

Area of Science:

• Behavioral Ecology
• Developmental Biology
• Evolutionary Biology

Background:

• Developmental plasticity influences population mean phenotypes, but its effect on within-population variation is less studied.
• Social experience is hypothesized to increase individual variation, facilitating the development of "social niches."

Purpose of the Study:

• To investigate how social experience during development affects behavioral and web structure variation in black widow spiders (Latrodectus hesperus).
• To compare the effects of social rearing, disturbance, and no disturbance on individual differences in adult spiders.

Main Methods:

• Juvenile black widow spiders were exposed to conspecific silk (social rearing), subjected to repeated disturbance, or left undisturbed.
• Behavior and web structure were measured repeatedly in adulthood.
• Repeatability and among-individual differences in traits were analyzed across treatments.

Main Results:

• Social rearing led to higher repeatability in some behavioral and web traits compared to control and disturbed groups.
• Repeated juvenile disturbance decreased among-individual differences in several traits.
• Social rearing effects sometimes overrode disturbance effects, indicating a prioritization of social cues.
• Individual differences established during development persisted into adulthood, suggesting stable effects.

Conclusions:

• Social experience is a significant developmental factor that can increase trait variation within a population.
• Juvenile disturbance can reduce individual differences, while social rearing may buffer against or override these effects.
• These findings highlight the role of diverse developmental experiences in shaping the evolution of social behavior and trait diversity.