Is female promiscuity constrained by the presence of her social mate? An experiment with bluethroats <Emphasis Type="Italic">Luscinia svecica</Emphasis>

Extra-pair paternity is common in birds and much research has focussed on the selective advantage of extra-pair matings for both sexes. In contrast, little attention has been given to the fact that in most species the majority of offspring are sired by the social male. We investigated whether extra-pair matings of female bluethroats (Luscinia svecica) are constrained by the presence of the pair male, by detaining males in cages on their territories for one morning during the peak of female fertility. The proportion of offspring sired by extra-pair males was higher in broods where males had been detained (35%) than in control broods (16%), while the proportion of broods that had at least one extra-pair offspring did not differ significantly between experimental (65%) and control broods (44%). Within the experimental group, levels of extra-pair paternity were not related to the day of experiment in relation to start of egg laying, but males caught early in the morning lost more paternity than males caught later on. Our results show that pair males exert constraints on the frequency of extra-pair paternity by being present during the period of peak fertility, which could be a direct effect of their mate guarding effort and/or due to an advantage in sperm competition for pair males.     

Female aggressive response and hormonal correlates—an intrusion experiment in a free-living passerine

The optimal mating system is rarely the same for males and females—whereas males usually benefit from attracting additional females to the territory, this could incur costs for the resident female. Females should therefore prevent prospecting females from settling on the territory. We studied the male and female behavioral and hormonal responses to simulated female territorial intrusions in free-living bluethroats during the pre-laying period. In the study population, polygyny occurs with potential fitness costs for the resident female. We recorded different aspects of aggressive behavior before and after presentation of a live female decoy and playback of female song. These behaviors were compared with a set of intrusions using a male decoy. At the end of a trial, the birds were captured, and blood samples were analyzed for androstenedione, testosterone, estradiol and corticosterone. During the pre-intrusion period, none of the females were observed. Females generally responded strongly to the female decoy by increased flight rate, vocalizations, and by conspicuous perching. Nearly half of the males displayed to the female decoy but never while the resident female was present. We suggest that resident female aggression in bluethroats prevents courtship by her mate and signals her mating status to the female intruder. Female aggression could therefore prevent additional females to settle on the territory and shape the mating system. Females that responded with song had higher levels of estradiol. These findings suggest that estradiol may support aggression in breeding female birds.     

Parent–offspring and sibling conflict in Galápagos fur seals and sea lions

Parent–offspring conflict theory is well supported by theoretical arguments. However, empirical observations are often difficult to interpret and have contradicted one of its most appealing predictions that parent and offspring should disagree over killing of nest or littermates. We present the first examples of deadly conflict between siblings of different cohorts. In Galápagos fur seals (Arctocephalus galapagoensis) and sea lions (Zalophus wollebaeki), mothers often wean their single offspring at 2 years. This leads to a situation where up to 23% of all pups are born while the older sibling is still being nursed. Younger siblings are disadvantaged by being born lighter than neonates without older still dependent siblings. Pups born while an older sib is still dependent grow less in early life (fur seal) and suffer increased early mortality (both species) through direct aggression or scramble competition with the older sibling. This effect is much stronger in years of high sea surface temperature (El Niño) indicating low marine productivity and if the older offspring is a male. In both species, mothers interfere aggressively in this conflict by defending the younger offspring. In years of El Niño, intense resistance to maternal aggression by the older offspring happens frequently in the fur seal. Such resistance against weaning can induce maternal neglect of the newborn. Given substantial year to year variation in offspring growth, maternal aggression forces weaning in the older sibling only if it has reached sufficient size to support itself by foraging. In Galápagos fur seals, pups with older siblings can either represent insurance against loss of older offspring or extra reproductive value.     

The rationality of resistance: alternatives for engagement in complex emergencies

The different conceptualisations of conflict in the complex emergency literature have profound implications on the perception of the agency of different groups and the prospects for conflict management. While much recent analysis has focused on the rational political and economic functions of violence, relatively little analysis has focused on why the majority of people chose not to resort to violence. Using Foucault's analysis of power relations, a new framework for conflict analysis is proposed which includes non-violent resistance as well as violence as a means of domination. Non-violent resistance is explored as a rational, highly adaptable response to acts of domination. A comprehensive understanding of conflict must recognise local forms of resistance and identify the barriers and opportunities for the engagement of the international humanitarian community with these groups. This engagement can be used to foster capacities for the creation of legitimate, inclusive, non-violent political and economic processes in the attempt to provide alternatives for everyone in the conflict. If the purpose of the study of complex emergencies is to understand the nature of various conflicts and, based on that understanding, make recommendations for possible routes to conflict management, the analysis of local resistance and efforts to foster it must become a major aspect of the research agenda.     

Coping strategies developed as a result of social structure and conflict: Kosovo in the 1990s

The end of 1989 brought with it political and economic decisions which resulted in Kosovo being stripped of its autonomy and the Albanian population being expelled from their jobs. These facts combined with ethnic tensions created a decade of conflict and oppression affecting hundreds of thousands of innocent civilians. Thousands of Kosovars moved overseas to seek work to support families at home, altering the way of life of the population of Kosovo irredeemably. The loss of income had serious repercussions on food security throughout the 1990s; possibilities of purchasing food were diminished, control on goods in 1998 reduced availability of foodstuffs, conflict affected accessibility to markets and shops and consequently food intake and nutritional status was compromised. The most vulnerable were those who had no family members overseas. Mass displacement of population due to ethnic cleansing during the war of spring 1999, further jeopardised food security status. Destruction at this time rendered large parts of Kosovo useless and resulted in a shift in the determinant of vulnerability in the post-war period: destruction of houses, land, livestock and agricultural products as well as loss of family members, became a far more pertinent indicator of food insecurity. The strong and clear links between conflict, socio-economic issues and food security are highlighted and discussed in this paper.     

Social capital and the political economy of violence: a case study of Sri Lanka

This article examines the links between militarised violence and social capital (trans)formation. It first maps out emerging theoretical and policy debates on social capital and violent conflict and questions a number of the assumptions underpinning these debates. This is followed by an empirical analysis of several war-affected communities in Sri Lanka. The case studies illustrate that the links between militarised violence and social capital are complex, dynamic and context specific. It is argued that social capital cannot be understood in isolation from political and economic processes, and the belief that violent conflict inevitably erodes social capital is questioned. Finally, the implications for external agencies are highlighted. Rather than focusing on engineering social capital, external agencies need to focus on understanding better the preconditions for social capital formation and how they can contribute to the creation of an enabling environment. This requires as a starting-point a rigorous analysis of political and economic processes.     

云南白马雪山自然保护区与周边社区冲突的产权问题研究

保护区内的生物多样性保护与周边社区经济发展之间的矛盾冲突是一个世界性的问题。以白马雪山自然保护区为研究对象,针对保护区的建设面临着巨大的人口压力、相当落后的经济状况和对资源的强烈需求等问题,深入研究资源管理的产权状况,探讨目前存在的产权不合理性,并进一步提出了保护区社区共管产权建设的合理模式。     

Devils lake emergency outlet diversion conflict

The Devils Lake Emergency Outlet Diversion conflict is systematically studied from a strategic viewpoint using the Graph Model for Conflict Resolution in order to obtain insights about the resolution of this nagging international dispute. By modelling the conflict for the situation existing as of July 2005, just before the project began operation, the dispute is put into proper perspective and, subsequently, a stability analysis is carried out to obtain potential resolutions or equilibria. The results of a sensitivity analysis accurately predict the deal which actually took place when Canada and the American state of North Dakota reached a negotiated settlement. Finally, suggestions are put forward for improving the Boundary Waters Treaty of 1909 between Canada and the United States.     

Transparency,consultation and conflict: Assessing the micro‐level risks surrounding the drive to develop Peru's Amazonian oil and gas resources

Since the 1990s, successive Governments in Peru have sought to expand the exploration and production of the country's oil and gas resources. This economic agenda poses significant opportunities and risks which are usually considered at the macro‐level and framed by debates regarding the so‐called “natural resource curse”. While risks such as “Dutch disease” are important to consider, a worrying set of short‐term issues surrounds the impacts of rapid changes brought on by oil and gas industrial development at the micro‐level, namely, those that affect local communities and the environment. In the case of Peru, this is especially relevant to the vast areas of ecologically sensitive and previously under‐developed Amazonia that are now under concession to oil and gas companies. Low levels of industry transparency combined with a lack of uniform free, prior and informed consent are exacerbating community‐level grievances, and the conflicts to which they can lead. As the oil and gas industry expands in the Peruvian Amazon, the risk of conflict is likely to prove far harder to minimize or ameliorate than are the challenges of managing industry revenues and the risk of currency appreciation most often associated with the natural resource curse.     

一种改进的混合交通交叉口安全仿真评价方法

为解决经典冲突分析模型SSAM中最小碰撞时间方法在冲突仿真中的不足,根据混合交通中机动车、非机动车及行人的运行特征并基于交通冲突理论,提出在交通仿真模型中易于实现的冲突时刻差法,即通过测量任意2股车流经过潜在冲突点的时间,计算冲突发生的时间差值。该方法可以通过交通仿真软件的二次开发方便地实现对混合交叉口交通安全状况的评估。最后以典型混合交通交叉口绿灯间隔评价为例,对比分析了2种方法的适用性。结果表明,冲突时刻差法比最小碰撞时间法更能细致刻画交叉口的安全水平;在不同的绿灯间隔水平下,后一种方法比前者漏检80%以上的交通冲突,冲突时刻差法更能适应混合交通交叉口安全仿真分析评价的需要。