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STUART J. MARSDEN 《Environmental management》2000,26(2):207-213
One of the UK's largest flocks of pochard Aythya ferina and tufted duck A. fuligula winters in Manchester's busy dockland redevelopment area. I examined the effects of human disturbance on the population,
and used this information to recommend minimal land-use restrictions that will help ensure the population's continued use
of the site. Birds fed at the docks every night, but on 75% of days, the flock flew to suburban or rural refuges in response
to disturbance. The common causes of disturbance, particularly pedestrians, did not affect the duck greatly, but disturbances
associated with building and redevelopment of the site (e.g., machinery) often made duck evacuate the dock. While birds were
no less likely to evacuate the docks as the winter progressed, they did show some short-term flexibility in their responses
to disturbance. For example, birds appeared able to sit out disturbances throughout the afternoon if they had avoided evacuation
of the docks during the morning. Birds spent only a small proportion of time feeding, and feeding activity was not heightened
following periods of exclusion from the docks due to disturbance. Daytime feeding activity was elevated during periods of
lowering temperatures, and despite heavy disturbance at the site, the impact of disturbance may only be significant during
the coldest period of the winter. During very cold spells, it is important to limit the incidence of unusual disturbances,
such as evening concerts and waterborne activities which tend to make duck evacuate the site. 相似文献
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The long-term population dynamics of the white-eyed pochard (Aythya nyroca) in the eastern Sea of Azov region was analyzed. It was found that the local population of this species tends to decrease in size. Clutch size, egg size, reproductive behavior, intraspecific clutches, embryonic mortality, and hatching success in this population were studied. The contents of PCDD and PCDF in the eggs of waterfowl were estimated. The eggs of white-eyed pochard, compared to other waterfowl, proved to contain abnormally high concentrations of xenobiotics. Possible causes of A. nyrocapopulation decline, including the impact of superecotoxicants, are discussed. 相似文献
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