Delayed plumage maturation in Lazuli buntings: tests of the female mimicry and status signalling hypotheses

The evolutionary importance of delayed plumage maturation (DPM) in passerines, the condition when more than 1 year is required to achieve adult-like coloration, remains highly contentious. Adaptive hypotheses propose that aggression from after 2nd-year (ASY) males or predation favors DPM in 2nd-year (SY) males, thereby increasing SY male survivorship or reproductive success. However, each hypothesis suggests a distinct selective mechanism explaining “how” this is accomplished. Alternatively, DPM may be a consequence of a nonadaptive molt constraint. We tested the female mimicry and status signalling hypotheses in territorial ASY male lazuli buntings (Passerinaamoena) using three sets of model presentation experiments. The female mimicry hypothesis proposes that dull SY male plumage deceptively mimics female plumage, and predicts that ASY males can not distinguish SY male from female plumage. The status signalling hypothesis proposes that dull SY male plumage honestly signals low competitive threat, and predicts that ASY males respond less aggressively to dull versus bright, ASY-like plumage. Contrary to the female mimicry hypothesis, ASY males distinguished between SY male and female plumage, as they were aggressive to SY male models exclusively and attempted to copulate with female models. Supporting the status signalling hypothesis, ASY males were significantly less aggressive to SY versus ASY male plumage. While DPM may result from a physiological constraint on bright SY male plumage, our results support the idea that dull plumage in an SY male's first breeding season may be maintained by selection to reduce aggression from ASY males, serving as a signal of competitive status. Received: 21 February 1997 / Accepted after revision: 16 June 1997     

厦门市放射性污染源现状调查分析

参照国家环保局颁发的《环境天然放射性水平调查规定》,在厦门市区开展了放射性污染源调查,对厦门市放射性污染源现状进行了分析和研究,对各类放射性污染源的环境影响作出评估,对放射性污染的发展趋势进行了预测,为厦门市放射性环境管理提供了重要的资料。     

Prioritizing species conservation programs based on IUCN Green Status and estimates of cost-sharing potential

Over 1 million species around the world are at risk of extinction, and conservation organizations have to decide where to invest their limited resources. Cost-effectiveness can be increased by leveraging funding opportunities and increasing collaborative partnerships to achieve shared conservation goals. We devised a structured decision-making framework to prioritize species’ conservation programs based on a cost–benefit analysis that takes collaborative opportunities into account in an examination of national and global conservation return on investment. Conservation benefit is determined by modifying the novel International Union for the Conservation of Nature Green Status for Species to provide an efficient, high-level measure that is comparable among species, even with limited information and time constraints. We applied this prioritization approach to the Wilder Institute/Calgary Zoo, Canada, a nonprofit organization seeking to increase the number of species it assists with conservation translocations. We sought to identify and prioritize additional species’ programs for which conservation translocation expertise and actions could make the most impact. Estimating the likelihood of cost-sharing potential enabled total program cost to be distinguished from costs specific to the organization. Comparing a benefit-to-cost ratio on different geographic scales allowed decision makers to weigh alternative options for investing in new species’ programs in a transparent and effective manner. Our innovative analysis aligns with general conservation planning frameworks and can be adapted for any organization.     

Tug-of-war over reproduction in a cooperatively breeding cichlid

In group-living animals, dominants may suppress subordinate reproduction directly and indirectly, thereby skewing reproduction in their favour. In this study, we show experimentally that this ability (‘power’) is influenced by resource distribution and the body size difference between unrelated dominants and subordinates in the cichlid Neolamprologus pulcher. Reproduction was strongly skewed towards the dominant female, due to these females producing more and larger clutches and those clutches surviving egg eating better than those of subordinate females, but was not so when subordinates defended a patch. If breeding shelters were provided in two patches, subordinate females were more likely to exclusively defend a patch against the dominant female and breed, compared to when the same breeding resource was provided in one patch. Relatively large subordinate females were more likely to defend a patch and reproduce. Females also directly interfered with each other’s reproduction by eating the competitors’ eggs, at which dominants were more successful. Although dominant females benefited from subordinate females due to alloparental care and an increase in egg mass, they also showed costs due to reduced growth in the presence of subordinates. The results support the view that the dominant’s power to control subordinate reproduction determines reproductive partitioning, in agreement with the predictions from tug-of-war models of reproductive skew.     

国际钻井现场环境保护技术

中原油田 ５００１钻井队,承钻了英国凯恩能源公司部署在孟加拉国 １５区块上的两口探井。由于当地政府的特殊要求,甲方从钻前工程到完井的每一道工序,严密的实施了环境保护措施。通过合作了解了许多国际惯例和掌握了许多应用于作业现场的先进技术,反映了目前国际市场的技术现状。     

我国废旧电子电器产品拆解技术、设备应用现状及改进建议

从我国废旧电子电器回收行业基本情况、专业技术人才情况、相关企业拆解技术设备情况等方面，阐述了我国废旧电子电器产品拆解技术、设备应用现状，并提出相关改进提升建议。     

四川省危险废物管理现状分析及评价

随着城市化进程的加快,危险废物的产生量快速增加,数量多、分布广、危害大、潜在利用价值高,管理处理难度大,因此带来了巨大的环境安全隐患。本文利用相关调查统计数据,分析了四川省危险废物产生特性及污染特性,指出危险废物管理过程中出现的问题已成为阻碍四川省循环经济发展及生态省建设的壁垒,针对出现的问题,提出了相关对策和建议。     

镇雄县乌江水系郭家河流域污染现状调查及总量预测分析

对郭家河流域进行系统的数据收集、实地调查、污染因子监测,并通过总量预测分析,掌握境内乌江水系郭家河流域各污染源,确定流域水质超标主要原因,提出针对性的保护措施。     

关于改善中国参与全球环境治理的战略思路

本文对全球环境治理的现状,中国当前在全球环境治理中的作用与面临的挑战,以及中国如何更好地参与全球环境治理进行了系统的总结.主要内容包括:全球环境治理成为全球治理的重要内容,全球环境治理当前由发达国家主导,全球环境治理中各方利益更加分化,非政府组织的影响越来越大,全球环境治理当前进展缓慢;中国日益成为全球环境治理的关注焦点,中国国内环保工作与全球环境治理有着巨大差别,中国国情的不断变化导致在全球环境治理中的立场摇摆;中国参与全球环境治理的能力不足、中国的非政府组织力量薄弱;中国应明确自身在全球环境治理中的利益,加强全球环境治理的意识,从熟悉学习阶段向主动参与制定规则转变,发挥我国环境非政府组织在全球环境治理中的积极作用,开展全球环境治理专项研究,加强全球环境治理人才队伍建设.     

长江三峡库区湖北段水华发生情况及成因分析

文章对长江三峡库区湖北段各支流水华发生情况在河流水系分布、发生时间、频次及水华类型等方面进行了分析,对水华发生的成因进行了探讨,并提出了相应的对策和建议。