scholarly journals Extrapair Fertilization in the Black-Browed Reed Warbler (Acrocephalus Bistrigiceps): Effects on Mating Status and Nesting Cycle of Cuckolded and Cuckolder Males

The Auk ◽  
2005 ◽  
Vol 122 (4) ◽  
pp. 1086-1096
Author(s):  
Shoji Hamao ◽  
Daichi S. Saito

Abstract We studied the relationship between the occurrence of extrapair fertilizations (EPFs) and mating status and nesting cycle of mates, respectively, in a population of Black-browed Reed Warblers (Acrocephalus bistrigiceps). Overall, 6.4% (9 of 140) of the chicks were sired by extrapair males, and 13.5% (5 of 37) of the broods contained at least one extrapair chick. Socially polygynous males were cuckolded more frequently than socially monogamous males (40.0% and 3.7%, respectively). In three of four cases where cuckolded males were polygynous, the fertile periods of their mates overlapped. Except for two floating males that obtained EPFs, five out of seven cuckolder males were paired. Males succeeded in EPFs when the fertile period of the extrapair females largely overlapped the incubation period of their own mates. These findings are consistent with the hypothesis that there are trade-offs between extrapair copulation activity and both mate guarding and rearing of nestlings. Fertilisation Extraconjugale chez Acrocephalus bistrigiceps: Effets des Mâles Infidèles et Cocus sur le Statut de Couple et le Cycle de Nidification

2002 ◽  
Vol 50 (6) ◽  
pp. 565 ◽  
Author(s):  
David J. Green ◽  
Anne Peters ◽  
Andrew Cockburn

We used multilocus DNA fingerprinting to assess parentage in the brown thornbill, Acanthiza pusilla, a socially monogamous Australian passerine. Extra-pair paternity was uncommon (6.2% of 178 offspring; 11.9% of 67 broods) and there was no evidence of intra-specific brood parasitism. Extra-pair paternity was limited because pairs spent more time together when females were fertile and males were able to evict intruding males before they could approach the female. Males were responsible for the close proximity of partners during the fertile period. Mate guarding therefore appears to be a male tactic aimed at preventing female infidelity rather than a cooperative behaviour of the pair aimed at preventing extra-pair copulations and/or female harassment. Females did not attempt to escape male guarding and were rarely observed to solicit copulations from intruding males. Nevertheless, females paired to smaller and younger males were more likely to cuckold their mates than females paired to larger and older males. This suggests that females may be more likely to seek or accept extra-pair matings when paired to small, young males or that old, large males are better at preventing their mates from engaging in extra-pair copulations. We found that male age but not male size influences mate-guarding behaviour. Older males tended to respond more aggressively to intruders. We therefore speculate that the relationship between male size/age and extra-pair paternity in brown thornbills may arise because female thornbills prefer large males as mates but are unable to express this preference as easily when paired to older males.


2009 ◽  
Vol 64 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Melanie Schubert ◽  
Carsten Schradin ◽  
Heiko G. Rödel ◽  
Neville Pillay ◽  
David O. Ribble

2020 ◽  
Author(s):  
Ajiang Chen ◽  
Pengli Cheng ◽  
Yajuan Luo

The phenomenon of "cancer villages" has emerged in many parts of rural China, drawing media attention and becoming a fact of social life. However, the relationship between pollution and disease is often hard to discern. Through sociological analysis of several villages with different social and economic structures, the authors offer a comprehensive, historically grounded analysis of the coexistence between the incidence of cancer, environmental pollution and villagers’ lifestyles, as well as the perceptions, claims and responses of different actors. They situate the appearance of "cancer villages" in the context of social, economic and cultural change in China, tracing the evolution of the issue over two decades, and providing deep insights into the complex interactions and trade-offs between economic growth, environmental change and public health.


Author(s):  
Tianwei Geng ◽  
Hai Chen ◽  
Di Liu ◽  
Qinqin Shi ◽  
Hang Zhang

Exploring and analyzing the common demands and behavioral responses of different stakeholders is important for revealing the mediating mechanisms of ecosystem service (ES) and realizing the management and sustainable supply of ES. This study took Mizhi County, a poverty-stricken area on the Loess Plateau in China, as an example. First, the main stakeholders, common demands, and behavioral responses in the food provision services were identified. Second, the relationship among stakeholders was analyzed. Finally, this study summarized three types of mediating mechanisms of food provision services and analyzed the influence of the different types of mediating mechanisms. The main conclusions are as follows: (1) Five main stakeholders in the study area were identified: government, farmers, enterprises, cooperatives, and middlemen. (2) Increasing farmers’ income is the common demand of most stakeholders in the study area, and this common demand has different effects on the behavioral responses of different stakeholders. (3) There are three types of mediating mechanisms in the study area: government + farmers mediating corn and mutton, government + enterprises mediating millet, and government + cooperatives mediating apples. On this basis, the effects of the different types of mediating mechanisms on variations in food yield, and trade-offs and synergies in typical townships, were analyzed.


2019 ◽  
Vol 2019 (4) ◽  
pp. 132-151 ◽  
Author(s):  
Raphael Bost ◽  
Pierre-Alain Fouque

Abstract Besides their security, the efficiency of searchable encryption schemes is a major criteria when it comes to their adoption: in order to replace an unencrypted database by a more secure construction, it must scale to the systems which rely on it. Unfortunately, the relationship between the efficiency and the security of searchable encryption has not been widely studied, and the minimum cost of some crucial security properties is still unclear. In this paper, we present new lower bounds on the trade-offs between the size of the client state, the efficiency and the security for searchable encryption schemes. These lower bounds target two kinds of schemes: schemes hiding the repetition of search queries, and forward-private dynamic schemes, for which updates are oblivious. We also show that these lower bounds are tight, by either constructing schemes matching them, or by showing that even a small increase in the amount of leaked information allows for constructing schemes breaking the lower bounds.


2018 ◽  
Vol 15 (1) ◽  
pp. 94-112 ◽  
Author(s):  
Daniëlle Cattel ◽  
Frank Eijkenaar ◽  
Frederik T. Schut

AbstractWorldwide, policymakers and purchasers are exploring innovative provider payment strategies promoting value in health care, known as value-based payments (VBP). What is meant by ‘value’, however, is often unclear and the relationship between value and the payment design is not explicated. This paper aims at: (1) identifying value dimensions that are ideally stimulated by VBP and (2) constructing a framework of a theoretically preferred VBP design. Based on a synthesis of both theoretical and empirical studies on payment incentives, we conclude that VBP should consist of two components: a relatively large base payment that implicitly stimulates value and a relatively small payment that explicitly rewards measurable aspects of value (pay-for-performance). Being the largest component, the base payment design is essential, but often neglected when it comes to VBP reform. We explain that this base payment ideally (1) is paid to a multidisciplinary provider group (2) for a cohesive set of care activities for a predefined population, (3) is fixed, (4) is adjusted for the population’s risk profile and (5) includes risk-mitigating measures. Finally, some important trade-offs in the practical operationalisation of VBP are discussed.


2020 ◽  
Vol 287 (1927) ◽  
pp. 20200463 ◽  
Author(s):  
Marion Orsucci ◽  
Pascal Milesi ◽  
Johanna Hansen ◽  
Johanna Girodolle ◽  
Sylvain Glémin ◽  
...  

The outcome of species range expansion depends on the interplay of demographic, environmental and genetic factors. Self-fertilizing species usually show a higher invasive ability than outcrossers but selfing and bottlenecks during colonization also lead to an increased genetic load. The relationship between genomic and phenotypic characteristics of expanding populations has, hitherto, rarely been tested experimentally. We analysed how accessions of the shepherd's purse, Capsella bursa-pastoris , from the colonization front or from the core of the natural range performed under increasing density of competitors. First, accessions from the front showed a lower fitness than those from the core. Second, for all accessions, competitor density impacted negatively both vegetative growth and fruit production. However, despite their higher genetic load and lower absolute performances, accessions from the front were less affected by competition than accessions from the core. This seems to be due to phenotypic trade-offs and a shift in phenology that allow accessions from the front to avoid competition.


2016 ◽  
Vol 283 (1825) ◽  
pp. 20152772 ◽  
Author(s):  
Eric S. Abelson

Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost–benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.


2019 ◽  
Vol 20 (2) ◽  
pp. 362-374
Author(s):  
Yoichi Inoue ◽  
Waidi Sinun ◽  
Kazuo Okanoya

Abstract Mating activity of a wild Mueller’s gibbon group (Hylobates muelleri) was observed in the Danum Valley Conservation Area, Sabah, Malaysia. The purpose of this study was to investigate the function of copulation calls in gibbons. The female emitted copulation calls at the time of intromission and pelvic thrusting. Copulation calls were composed of two notes and one of them was sung only while mating. Approximately half of copulation calls were sung near the range boundary. Mating with copulation calls sometimes occurred while singing. According to the model that female copulation calls have evolved under the selective pressures of risk of infanticide and sperm competition, copulation calls should be rare in species with little female promiscuity. As gibbons usually live in pair-living social organization and have a monogamous mating system, no vocal signals by female gibbons are considered to be needed. However, clear copulation calls were emitted by the female. It suggests that the relationship between paired gibbons is unstable. Copulation calls by the female Mueller’s gibbon may function to increase mate guarding and strengthen the pair bond.


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