Effects of social experience, aggressiveness and comb size on contest success in male domestic fowl

Sexual conflict and social networks in bed bugs: effects of social experience

Living in groups can provide essential experience that improves sexual performance and reproductive success. While the effects of social experience have drawn considerable scientific interest, commonly used behavioral assays often do not capture the dynamic nature of interactions within a social group. Here, we conducted 3 experiments using a social network framework to test whether social experience during early adulthood improves the sexual competence of bed bugs (Cimex lectularius) when placed in a complex and competitive group environment. In each experiment, we observed replicate groups of bed bugs comprising previously socialized and previously isolated individuals of the same sex, along with an equal number of standardized individuals of the opposite sex. Regardless of whether we controlled for their insemination history, previously isolated males mounted and inseminated females at significantly higher rates than previously socialized males. However, we found no evidence of social experience influencing our other measures of sexual competence: proportion of mounts directed at females, ability to overcome female resistance, and strength of opposite-sex social associations. We similarly did not detect effects of social experience on our female sexual competence metrics: propensity to avoid mounts, rate of successfully avoiding mounts, opposite-sex social association strength, and rate of receiving inseminations. Our findings indicate that early social experience does not improve sexual competence in male and female bed bugs.

Social behavior in farm animals: Applying fundamental theory to improve animal welfare

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important behavioral decisions that influence welfare. In this review, we focus on social interactions as perhaps the most dynamic and challenging aspects of the lives of farm animals. Social stress is a leading welfare concern in livestock, and substantial variation in social behavior is seen at the individual and group level. Here, we consider how a fundamental understanding of social behavior can be used to: (i) understand agonistic and affiliative interactions in farm animals; (ii) identify how artificial environments influence social behavior and impact welfare; and (iii) provide insights into the mechanisms and development of social behavior. We conclude by highlighting opportunities to build on previous work and suggest potential fundamental hypotheses of applied relevance. Key areas for further research could include identifying the welfare benefits of socio–positive interactions, the potential impacts of disrupting important social bonds, and the role of skill in allowing farm animals to navigate competitive and positive social interactions. Such studies should provide insights to improve the welfare of farm animals, while also being applicable to other contexts, such as zoos and laboratories.

Fighting over defense chemicals disrupts mating behavior

Studies on intraspecific contest behavior predominantly focus on contests between individuals of the same sex, however contest behavior is also expected to occur between individuals of the opposite sex including possible mates. Here we investigate potential trade-offs between mating and fighting behavior in the turnip sawfly (Athalia rosae). Adults of this species collect chemical defense compounds (clerodanoids) directly from plants but also indirectly by nibbling on conspecifics that have already obtained clerodanoids, a highly aggressive behavioral interaction. An A. rosae individual without clerodanoids may therefore be the potential mate or attacker of an individual of the opposite sex that has gained clerodanoids. To test the effect of clerodanoids on agonistic and mating behavior we paired females and males with or without clerodanoid access in a two-way factorial design. We show that asymmetrical clerodanoid acquisition between female-male pairs causes an increase in agonistic nibbling behavior, irrespective of sex, and moreover that conflict between individuals delays mating behavior. Our study highlights the importance of investigating agonistic intersex interactions, which can occur when adults are able to acquire valuable non-reproductive resources from a potential partner.