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Male Performance (male + performance)
Selected AbstractsMale Performance and Body Size Affect Female Re-Mating Occurrence in the Orb-Web Spider Leucauge mariana (Araneae, Tetragnathidae)ETHOLOGY, Issue 12 2009Anita Aisenberg Females can affect male probabilities of paternity success through behavioural, morphological and/or physiological processes occurring during or after copulation. These processes under female-control include the acceptance or rejection of mating attempts by subsequent males. Leucauge mariana is an orb weaving spider that shows male mate guarding of penultimate females, male,male competition on female webs and copulatory plugs, suggesting a polyandric mating system. The aim of the present study was to ascertain whether male behaviour during courtship and copulation in L. mariana relate with female re-mating decisions. Forty-three virgin females were exposed to up to three males until they mated. In 24 cases, the copulatory plug was absent after mating and females were exposed the next day to up to three other males. Eighteen females accepted a second mating. Relatively larger females were more receptive to second matings and were more likely to copulate if the second male was smaller. Longer duration of female tapping and abdominal bobbing during courtship, and first copulations with less short insertions and more flubs, were associated with increased female acceptance to second matings. The results indicate cryptic female choice on male courtship and copulatory performance and suggest female-control over the determination of male mating success in this spider species. [source] The influence of age on reproductive performance in the Brown ThornbillJOURNAL OF AVIAN BIOLOGY, Issue 1 2001David J. Green I examined age effects on reproduction in the Brown Thornbill Acanthiza pusilla in Canberra, Australia. I found that the reproductive performance of both males and females improved with age, although only age-related improvement in male performance had a significant effect on annual reproductive success. Reproductive success improved with male age as a result of improved performance during two stages of the breeding cycle: first-year males were less likely to fledge young than those aged two or more, while both first and second-year males were less successful at raising fledglings to independence than males of three or more. Male performance appears to improve over three years as they gain experience at provisioning nestlings and caring for fledglings without attracting predators, rather than as a direct result of improved foraging skills. In contrast, reproductive success only improved slightly with female age, although females of two or more years initiated their first clutch earlier in the season than one-year-old females, and tended to be more likely to re-nest if a breeding attempt failed. The poor performance of young females appears unlikely to be related to their foraging ability but may be associated with costs imposed by dispersing to a breeding vacancy earlier in the year. Although the reproductive performance of Brown Thornbills improves considerably with age I found no evidence that performance improved as a result of repeated breeding attempts with the same partner. [source] Methoprene modulates the effect of diet on male melon fly, Bactrocera cucurbitae, performance at mating aggregationsENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2010Ihsan ul Haq Abstract The effect of access to dietary protein (P) (hydrolyzed yeast) and/or treatment with a juvenile hormone analogue, methoprene (M), (in addition to sugar and water) on male aggregation (lekking) behaviour and mating success was studied in a laboratory strain of the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae). Six-day-old males were treated with (1) protein and methoprene (M+P+), (2) only protein (M,P+), or (3) only methoprene (M+P,), and compared with 14-day-old sexually mature untreated males (M,P,). The lekking behaviour of the four groups of males when competing for virgin sexually mature females (14,,16 days old) was observed in field cages. The following parameters were measured at male aggregations: lek initiation, lek participation, males calling, male,male interaction, female acceptance index, and mating success. For all these parameters, the M+P+ males significantly outperformed the other males. Moreover, for all parameters, there was a similar trend with M+P+ > M,P+ > M,P, > M+P,. More M+P+ males called and initiated and participated in lek activities than all other types of male, which resulted in higher mating success. They had also fewer unsuccessful copulation attempts than their counterparts. Whereas treatment with methoprene alone had a negative effect in young males with only access to sugar, access to dietary protein alone significantly improved young male sexual performance; moreover, the provision of methoprene together with protein had a synergistic effect, improving further male performance at leks. The results are of great relevance for enhancing the application of the sterile insect technique (SIT) against this pest species. The fact that access to dietary protein and treatment of sterile males with methoprene improves mating success means that SIT cost-effectiveness is increased, as more released males survive to sexual maturity. [source] When fathers make the difference: efficacy of male sexually selected antimicrobial glands in enhancing fish hatching successFUNCTIONAL ECOLOGY, Issue 1 2010Matteo Pizzolon Summary 1.,Egg and offspring resistance to pathogens is a major determinant of survival and has been mainly ascribed to maternal factors. However, paternal production of antimicrobials was recently suggested to increase offspring survival in species where males perform egg care. 2.,In the peacock blenny, Salaria pavo, a demersal spawning species where males exhibit a pair of anal glands producing lysozyme-like compounds, we tested the antimicrobial activity and the egg protection efficacy of these glands. The anal gland secretion (AGS) has an inhibitory effect on the growth of both Gram-negative and Gram-positive bacteria, including those causing the most severe fish diseases in marine culture. The egg clutches cared for by males deprived of anal glands have a significantly lower survival rate than those cared for by sham-operated males and non-viable eggs showed clear signs of bacterial infection. 3.,Anal gland secretion production and its protein content are proportional to gland size. In species where male parental care plays a crucial role in offspring survival, females are expected to assess mates selecting those traits that are reliably associated with parental ability. Hence, we experimentally challenged females with dummy males differing in anal gland size. Females definitely preferred dummy males with larger anal glands, suggesting that their choice is driven by the pursuit of direct fecundity benefits. 4.,These findings indicate that antimicrobial production is a crucial component of male parental care. The contribution of antimicrobials to male performance as fathers suggests that the development of traits devoted to this function may influence male attractiveness and be sexually selected. [source] The influence of age on reproductive performance in the Brown ThornbillJOURNAL OF AVIAN BIOLOGY, Issue 1 2001David J. Green I examined age effects on reproduction in the Brown Thornbill Acanthiza pusilla in Canberra, Australia. I found that the reproductive performance of both males and females improved with age, although only age-related improvement in male performance had a significant effect on annual reproductive success. Reproductive success improved with male age as a result of improved performance during two stages of the breeding cycle: first-year males were less likely to fledge young than those aged two or more, while both first and second-year males were less successful at raising fledglings to independence than males of three or more. Male performance appears to improve over three years as they gain experience at provisioning nestlings and caring for fledglings without attracting predators, rather than as a direct result of improved foraging skills. In contrast, reproductive success only improved slightly with female age, although females of two or more years initiated their first clutch earlier in the season than one-year-old females, and tended to be more likely to re-nest if a breeding attempt failed. The poor performance of young females appears unlikely to be related to their foraging ability but may be associated with costs imposed by dispersing to a breeding vacancy earlier in the year. Although the reproductive performance of Brown Thornbills improves considerably with age I found no evidence that performance improved as a result of repeated breeding attempts with the same partner. [source] High divorce rates in Corsican blue tits: how to choose a better option in a harsh environmentOIKOS, Issue 3 2000Jacques Blondel We investigate which hypothesis, the "better mate hypothesis" or the "better territory hypothesis" best explains the unusually high divorce rate (59%) in a population of blue tits (Parus caeruleus) living in a sclerophyllous habitat characterised by severe environmental constraints (trophic, parasitic, climatic) on the island of Corsica, France. Using data from the breeding seasons 1985,1998 and from a brood size experiment (1990,1993) we examined the causes of divorce and their consequences on breeding performance, mate assortment and territory choice. Breeding performance had no significant effect on whether birds re-united or divorced in the next breeding season. Re-uniting pairs did better than divorced females and the latter improved their breeding performance compared to prior to divorce, but this was mainly due to age and territory effects. There were no differences in male performance depending on whether they re-united or divorced. The age combination of pairs did not differ between re-uniting and divorcing pairs, but mate assortment changed after divorce with males re-mating more often with older partners than females. Manipulation of brood size showed a trend for birds with enlarged broods to divorce more. Pairs responded significantly to territory quality by divorcing more often in poor than in good breeding sites. Both faithful pairs and male divorcees had shorter breeding dispersal distances than female divorcees. Divorce rates were determined by the large differences in quality among breeding sites. Males, whatever their status, usually retained their previous territory whereas divorced females moved significantly longer distances and improved their breeding site. Moving to a better territory after divorce benefits only females which appear to be the choosing sex in the decision to divorce. This study strongly supports the "habitat mediated hypothesis" and we suggest that the large observed intraspecific variation in the magnitude of divorce rates in many species of birds is mostly determined by habitat characteristics. [source] The orthodoxization of ritual practice in western AnatoliaAMERICAN ETHNOLOGIST, Issue 4 2009KIMBERLY HART ABSTRACT In rural western Turkey, villagers have replaced male performances of davul (bass drum) and zurna (double-reed wind instrument) as well as men's dancing with mevluts, special prayer services, and they have replaced women's dances to taped or live electric harmonium music with sohbets, sermons. Villagers are motivated to transform "cultural practices" that appear "backward" from the perspective of state-based ideologies of cultural progress and that are considered sinful from the perspective of Islamists. I trace their quests for spiritual and secular salvation and how they relate to the construction of a modernist Islamic worldview. [source] Impact of carbohydrate supplementation during endurance training on glycogen storage and performanceACTA PHYSIOLOGICA, Issue 2 2009L. Nybo Abstract Aim:, Glucose ingestion may improve exercise endurance, but it apparently also influences the transcription rate of several metabolic genes and it alters muscle metabolism during an acute exercise bout. Therefore, we investigated how chronic training responses are affected by glucose ingestion. Methods:, In previously untrained males performance and various muscular adaptations were evaluated before and after 8 weeks of supervised endurance training conducted either with (n = 8; CHO group) or without (n = 7; placebo) glucose supplementation. Results:, The two groups achieved similar improvements in maximal oxygen uptake and peak power output during incremental cycling (both parameters elevated by 17% on average) and both groups lost ,3 kg of fat mass during the 8 weeks of training. An equal reduction in respiratory exchange ratio (0.02 units) during submaximal exercise was observed in both groups. Beta-hydroxyacyl-CoA-dehydrogenase activity was increased in both groups, however, to a larger extent in the placebo group (45 ± 11%) than CHO (23 ± 9%, P < 0.05). GLUT-4 protein expression increased by 74 ± 14% in the placebo group and 45 ± 14% in CHO (both P < 0.05), while resting muscle glycogen increased (P < 0.05) to a larger extent in the placebo group (96 ± 4%) than CHO (33 ± 2%). Conclusion:, These results show that carbohydrate supplementation consumed during exercise training influences various muscular training adaptations, but improvements in cardiorespiratory fitness and reductions in fat mass are not affected. [source] | ||||||||||