�ber die Navigation der V�gel

Schmidt-Koenig, Klaus

doi:10.1007/bf00610407

Cited by 12 publications

(1 citation statement)

References 20 publications

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“…Compensating completely for the actual lateral drift has the advantage that a bird must not reorient during its subsequent migratory journey -i.e. a vector navigation program (Schmidt-Koenig 1973) would be sufficient to arrive at the specified goal. Allowing lateral drift would imply either true navigation (Gwinner 1971) or the ability to remember experienced drift and compensate for it during a subsequent flight stage (Gauthreaux 1978;Rabol and Thorup 2001), or the toleration of a displacement from the goal.…”

Section: Flight Direction and Speedmentioning

confidence: 99%

Birds: blowin’ by the wind?

2006

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Migration is a task that implies a route, a goal and a period of time. To achieve this task, it requires orientation abilities to find the goal and energy to cover the distance. Completing such a journey by flying through a moving airspace makes this relatively simple task rather complex. On the one hand birds have to avoid wind drift or have to compensate for displacements to reach the expected goal. On the other hand flight costs make up a large proportion of energy expenditure during migration and, consequently, have a decisive impact on the refuelling requirements and the time needed for migration. As wind speeds are of the same order of magnitude as birds' air speeds, flight costs can easily be doubled or, conversely, halved by wind effects. Many studies have investigated how birds should or actually do react to winds aloft, how they avoid additional costs or how they profit from the winds for their journeys. This review brings together numerous theoretical and empirical studies investigating the flight behaviour of migratory birds in relation to the wind. The results of these studies corroborate that birds select for favourable wind conditions both at departure and aloft to save energy and that for some long-distance migrants a tail-wind is an indispensable support to cover large barriers. Compensation of lateral wind drift seems to vary between age classes, depending on their orientation capacities, and probably between species or populations, due to the variety of winds they face en route. In addition, it is discussed how birds might measure winds aloft, and how flight behaviour with respect to wind shall be tested with field data.

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Section: Flight Direction and Speedmentioning

confidence: 99%