Trading or coercion? Variation in male mating strategies between two communities of East African chimpanzees

Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological Market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolise access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (P.t. schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading—of grooming for mating—by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism–egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees’ willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness

Results of a three-year follow-up and quality of life dynamics after pulmonary thromboendarterectomy

Aim. To evaluate the results of a three-year follow-up of patients with chronic thromboembolic pulmonary hypertension (CTEPH) and quality of life (QOL) dynamics after pulmonary thromboendarterectomy (PTE).Material and methods. The study included 125 patients with CTEPH aged 49,7± 11,9 years. Three-year follow-up included the recording of adverse cardiovascular events, surgeries, death during the period from the end of hospitalization and up to three years. The SF-36 questionnaire was used to assess physical and mental wellbeing before and three years after PTE. Multivariate linear regression was used to assess the factors affecting QOL in the long-term postoperative period.Results. During a three-year follow-up, adverse cardiovascular events was recorded in 1,9% of patients. One patient underwent coronary artery bypass graft surgery and one patient — cholecystectomy. Reoperative PTE was not carried out. The overall three-year survival rate was 90,4%.At baseline, patients with CTEPH had a low level of physical and mental well-being (<40 points). Three years after the operation, these parameters significantly increased (p<0,05), but did not exceed 50 points. Multivariate linear regression revealed an unfavorable effect of early postoperative residual pulmonary hypertension on the physical health three years after PTE. Other factors (age, sex, body weight, comorbidity, hospital acquired complications) did not affect the physical and emotional aspects of QOL.Conclusion. Three-year survival rate in patients with CTEPH after PTE was 90,4%. During the follow-up period, no recurrent thromboembolic events were recorded. Adverse cardiovascular events were recorded in 1,9% of patients. Three years after surgery, the physical and mental health increased in comparison with preoperative values, but did not exceed 50 points on the SF-36 questionnaire. The physical aspect of QOL after surgery is affected by early postoperative residual pulmonary hypertension

Botanical gardens and arboreta of higher educational institutions of Federal agency on education of Ministry of education and science of Russian Federation

Botanical gardens and arboreta of higher educational institutions of Federal agency on education of Ministry of education and science of Russian Federatio