Intrasexual aggression reduces mating success in field crickets

This work was supported by the UK Natural Environment Research Council (NE/L011255/1 and NE/T000619/1).Aggressive behaviour is thought to have significant consequences for fitness, sexual selection and the evolution of social interactions, but studies measuring its expression across successive encounters?both intra- and intersexual?are limited. We used the field cricket Teleogryllus oceanicus to evaluate factors affecting repeatability of male aggression and its association with mating success. We quantified focal male aggression expressed towards partners and received from partners in three successive, paired trials, each involving a different male partner. We then measured a proxy of focal male fitness in mating trials with females. The likelihood and extent of aggressive behaviour varied across trials, but repeatability was negligible, and we found no evidence that patterns of focal aggression resulted from interacting partner identity or prior experience. Males who consistently experienced aggression in previous trials showed decreased male mating ?efficiency??determined by the number of females a male encountered before successfully mating, but the effect was weak and we found no other evidence that intrasexual aggression was associated with later mating success. During mating trials, however, we observed unexpected male aggression towards females, and this was associated with markedly decreased male mating efficiency and success. Our findings suggest that nonadaptive aggressive spillover in intersexual mating contexts could be an important but underappreciated factor influencing the evolution of intrasexual aggression.Publisher PDFPeer reviewe

New guidelines for the perioperative care of people living with frailty undergoing elective and emergency surgery—a commentary

Frailty is common in the older population and is a predictor of adverse outcomes following emergency and elective surgery. Identification of frailty is key to enable targeted intervention throughout the perioperative pathway from contemplation of surgery to recovery. Despite evidence on how to identify and modify frailty, such interventions are not yet routine perioperative care. To address this implementation gap, a guideline was published in 2021 by the Centre for Perioperative Care and the British Geriatrics Society, working with patient representatives and all stakeholders involved in the perioperative care of patients with frailty undergoing surgery. The guideline covers all aspects of perioperative care relevant to adults living with frailty undergoing elective and emergency surgery. It is written for healthcare professionals, as well as for patients and their carers, managers and commissioners. Implementation of the guideline will require collaboration between all stakeholders, underpinned by an implementation strategy, workforce development with supporting education and training resources, and evaluation through national audit and research. The guideline is an important step in improving perioperative outcomes for people living with frailty and quality of healthcare services. This commentary provides a summary and discussion of the evidence informing the standards and recommendations in the published guideline