Temperature Mediates Shifts in Individual Aggressiveness, Activity Level, and Social Behavior in a Spider

Although in recent years behavioral syndromes have received a wealth of attention, how traits within syndromes respond to changing environments is not well resolved. Here, we test the effects of temperature on a suite of behavioral traits in the spider Anelosimus studiosus to determine (1) whether there are shifts in individuals' social tendency, activity level, and foraging behavior in response to temperature, (2) if these traits shift are in the direction predicted by within-population axes of trait covariance, and (3) whether the effects of temperature differ among individuals. In previous work, we documented a behavioral syndrome in A. studiosus where increased tolerance of conspecifics is correlated with decreased activity level and aggressiveness toward prey. Furthermore, there are distinct among-population differences in behavior, where individuals from warm sites tend to be more aggressive and active than individuals from cold sites. Our data here reveal that at warmer temperatures A. studiosus exhibit diminished tolerance of conspecifics, increased activity levels, shorter latencies of attack, and increased tendencies to attack multiple prey items. Furthermore, we found that individual differences in behavior were consistent across temperature regimes for the majority of behavioral traits considered here: social tendency, activity level, and latency of attack. These findings are consistent with the hypothesis that these behaviors are linked together by shared genetic underpinnings (e.g., metabolic differences) and shift non-independently in response to contemporary abiotic environment (i.e., temperature). Furthermore, our data suggest that temperature itself could be responsible for the among-population variation in social structure in A. studiosus.