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Roswitha Wiltschko Cordula Haugh Michael Walker Wolfgang Wiltschko 《Behavioral ecology and sociobiology》1998,43(4-5):297-300
Although the sun compass of birds is based on learning the sun's arc during development, it was unclear whether birds can
use the sun when its apparent movement is reversed, in particular, whether northern birds that have been introduced into the
southern hemisphere can use the southern sun. To answer this question, clock-shift experiments were performed with local homing
pigeons in Auckland, New Zealand (37°S). In three fast-shift tests and two slow-shift tests, the experimental birds showed
deflections from the untreated controls that were the mirror images of those observed in the northern hemisphere. These results
clearly show that homing pigeons in New Zealand use a sun compass that is adapted to the situation in the southern hemisphere.
The learning processes establishing the compensation mechanisms thus appear to be free of constraints concerning the direction
of the sun's movement. Differences from recent findings with migratory birds, where the direction of celestial rotation proved
of crucial importance for establishing the migratory direction, are discussed: the differences may arise from the different
orientation tasks, in particular, from the involvement of innate information in establishing the migratory direction.
Received: 13 November 1997 / Accepted after revision: 28 February 1998 相似文献
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Wolfgang Pflüger 《Environmental Sciences Europe》1998,10(4):254-256
The development of new active ingredients and formulations is increasingly influenced by costs and regulations in the frame of pesticide registration procedures. Lawmakers and administrators therefore take over more responsibility, not only for the subject of regulation, but also for fair and balanced rules which can be predicted in the long-term. There are, however, deficiencies in the choice of certain quality standards — like in the European drinking water directive — which are not risk-related and which are susceptible to giving misleading guidance. Testing requirements should be scrutinized for efficiency, i.e. whether the increase in knowledge and safety is in reasonable proportion to the invested resources. 相似文献
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This study investigates the effects of workers' perceived participation in democratic decision‐making on their prosocial behavioral orientations, democratic values, commitment to the firm, and perceptions of socio‐moral climate. The sample consists of 325 German‐speaking employees from 22 companies in Austria, North Italy, and Southern Germany that vary in their level of organizational democracy (social partnership enterprises, workers' co‐operatives, democratic reform enterprises, and employee‐owned self‐governed firms). The findings suggest that the extent employees participate in democratic forms of organizational decision‐making is positively related to the firm's socio‐moral climate as well as to their own organizational commitment and prosocial and community‐related behavioral orientations. The results also indicate that socio‐moral climate is positively related to employees' organizational commitment. The effect of participation in decision‐making on organizational commitment is partially mediated by socio‐moral climate. Implications for promoting societal and organizational civic virtues among individuals are described. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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