119 research outputs found
Geschlechtsdemorphismus und Wanderaktivität des Amerikanischen Aales(Anguilla rostrata) in Fließgewässern und Flußmündungen von Rhode Island
The effects on a pike (Esox lucius L.) population of intensive fishing in a South Swedish lake
Role of gill rakers in size-selective predation by lake whitefish, Coregonus clupeaformis
Under a neighbour's influence: public information affects stress hormones and behaviour of a songbird
Socially acquired information improves the accuracy and efficiency of environmental assessments and can increase fitness. Public information may be especially useful during unpredictable food conditions, or for species that depend on resources made less predictable by human disturbance. However, the physiological mechanisms by which direct foraging assessments and public information are integrated to affect behaviour remain largely unknown. We tested for potential effects of public information on the behavioural and hormonal response to food reduction by manipulating the social environment of captive red crossbills (Loxia curvirostra). Red crossbills are irruptive migrants that are considered sensitive to changes in food availability and use public information in decision making. Here, we show that public information can attenuate or intensify the release of glucocorticoids (i.e. stress hormones) during food shortage in red crossbills. The observed modulation of corticosterone may therefore be a physiological mechanism linking public information, direct environmental assessments and behavioural change. This mechanism would not only allow for public information to affect individual behaviour, but might also facilitate group decision making by bringing group members into more similar physiological states. The results further suggest that stressors affecting entire populations may be magnified in individual physiology through social interactions
Results of whitefish, Coregonus lavaretus L., fingerling stocking in the lower part of the Sotkamo water course, northern Finland
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