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Juan Moreno Santiago Merino Jaime Potti Ana de León Rosa Rodríguez 《Behavioral ecology and sociobiology》1999,46(4):244-251
We manipulated parental work load without changing brood size in a population of pied flycatchers Ficedula hypoleuca by removing two primaries (7 and 9) from each wing of females, thus reducing wing area and increasing flight costs. At other
nests, we offered supplementary food in the form of live mealworms (10–20 g daily from hatching) to reduce brood demand and
thus parental foraging costs. Other nests were left as controls. The daily energy expenditure of females feeding 12-day-old
nestlings was measured with doubly labelled water D2
18O. Females in both treatments expended the same amount of energy, fed at the same rate and had similar body masses to birds
in the control group. No effect of treatment on male mass and feeding effort was detected. More nestlings, however, died in
nests of handicapped females. Nestlings of handicapped females had significantly lower body mass and haematocrit values than
nestlings in food-supplemented nests, with nestlings in control nests occupying an intermediate position. The effects of both
treatments on nestling mass, haematocrit values and mortality rates were only noticeable in nests infested with mites. Maternal
energy expenditure is apparently constrained and offspring pay the costs imposed by reduced provisioning rate or increased
demand caused by ectoparasites, while receiving benefits when food supply improves. The presumption that avian reproductive
costs derive from changes in a flexible energy output may not be met in many cases.
Received: 24 October 1998 / Received in revised form: 15 March 1999 / Accepted: 26 April 1999 相似文献
985.
邢振纲 《城市环境与城市生态》1999,12(1):1-6
本文全面回顾了1998年天津市环境保护工作,分析了当前形势以及进一步做好工作应把握的几个问题。围绕抓住机遇,打好天津市环境保护“一控双达标”攻坚战,提出了1999年的工作目标任务及具体措施。 相似文献
986.
泉州市规划区大气污染物总量控制及分配 总被引:1,自引:0,他引:1
林巍 《城市环境与城市生态》1999,12(3):21-24
合理的污染排放总量控制及分配是保证城市发展和环境保护和相协调的重要条件。COZEE-中国沿海环境保护增强工作以泉州市为试点开展IEMP示范项目,通过将国外先进经验,计算方法与当地实际相结合,制定出泉州市规划区大气污染物总量控制及分配方案,本文介绍IEMP项目大气污染总量控制,分配的基本思路及方法,这对我国沿海经济快速发展地区的总量控制具有一定的借鉴作用。 相似文献
987.
针对工业固体废物如何进行容量总量控制的问题,在研究工业固体废物中有毒有害物质污染迁移转化规律的基础上,提出了相对工业固体废物中有毒有害物质进入大气、地表水体、地下水和在生物体内积累的相对容量总量控制概念,并探讨了城市或区域工业固体废物容量总量控制的确定方法 相似文献
988.
湖泊水库水体氮、磷允许纳污量定量研究 总被引:13,自引:0,他引:13
在充分考虑湖库水体污染物实际自净能力、并分析其出流污染物浓度分布规律的基础上,根据风险分析理论和Monte Carlo模拟方法,提出了湖库水体氮、磷允许纳污量计算方法,指出:在满足湖库水体污染物浓度达标率90%以上的条件下,所对应的水体污染物降解量才是湖泊水库水体氮、磷允许纳污量.通过实际算例对水库总氮、总磷允许纳污量的计算,说明了所提出的计算方法的适用性. 相似文献
989.
990.
Md. Rezaul Karim Habibur Rahman Bejoy Khan Amimul Ahsan Md. Rahadujjaman Shadman Alam Rakibul Hasan Tabriz Tajwar Sharif Saad Farooq 《环境质量管理》2023,32(4):53-63
Potable and equitable drinking water (DW) is a fundamental human right and essential for human health. This study is conducted to assess the groundwater and jar water quality of the roadside restaurants and tea stalls used for drinking by the local people around the Gazipur City area in Bangladesh. Water samples from 173 restaurants and tea stalls are collected. The physico-chemical and biological parameters are analyzed according to the guidelines and standards. The results illustrate that the color, EC, and Mn of 41%, 80%, and 62% of the samples, respectively, exceed the WHO and Environmental Conservation Rules (ECR) standards. In addition, E. coli and total coliform exceeding the threshold standards are found in 47% and 64% of the water samples, respectively. The contamination of DW by fecal coliforms is confirmed and supported by prior studies, which indicates that the DW supplied in restaurants and tea stalls are unsafe because of the possible presence of pathogens. These may cause potential health hazards to consumers from various water-borne diseases. Poor sanitation, unhygienic practices, and improper disposal of wastewater are responsible for the microbial contamination of DW. So, the authorities in charge of these places should take the right regulatory steps, such as regular sanitation inspections, DW quality monitoring, hand-washing practices, and better sanitation in these places. 相似文献