منابع مشابه
Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition
possibility that the cowbird trapping was ineffectively implemented. Hall and Rothstein digress somewhat from local cowbird-control removals to potential landscape alternatives. Sorely overlooked in that treatment was a critical appraisal of broad-scale control options. In fact, data and analyses of several studies elsewhere in this volume suggest potential cowbird effects on host communities a...
متن کاملAerodynamics of gliding flight in common swifts.
Gliding flight performance and wake topology of a common swift (Apus apus L.) were examined in a wind tunnel at speeds between 7 and 11 m s(-1). The tunnel was tilted to simulate descending flight at different sink speeds. The swift varied its wingspan, wing area and tail span over the speed range. Wingspan decreased linearly with speed, whereas tail span decreased in a nonlinear manner. For ea...
متن کاملGliding Swifts Attain Laminar Flow over Rough Wings
Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the win...
متن کاملSudden weather deterioration but not brood size affects baseline corticosterone levels in nestling Alpine swifts.
While evidence is accumulating that stress-induced glucocorticoid responses help organisms to quickly adjust their physiology and behaviour to life-threatening environmental perturbations, the function and the ecological factors inducing variation in baseline glucocorticoid levels remain poorly understood. In this study we investigated the effects of brood size by experimentally manipulating th...
متن کاملDrinking norms versus drinking behavior.
Data from 1002 households indicated that contextual factors (group size, subsequent activity) and individual difference factors (sex, extroversion, drinking frequency) differentially influenced consumption and normative ratings. These findings suggest that contextual cues serve as determinants of drinking norms and that drinking behavior reflects individual variation in sensitivity to these cues.
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ژورنال
عنوان ژورنال: Emu
سال: 1919
ISSN: 0158-4197
DOI: 10.1071/mu919068b