Effect of wind on the foraging behaviour of Common and Sandwich Terns
Taylor, I.R. (1983). Effect of wind on the foraging behaviour of Common and Sandwich Terns. Ornis Scandinavica 14: 90-96
www.jstor.org/stable/3676011
In: Ornis Scandinavica. Munksgaard: Copenhagen. ISSN 0030-5693, more
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| Abstract |
The study was done on the estuary of the river Ythan, Aberdeenshire, Scotland. During high tide, when preying on Clupeidae, capture rates achieved by Common Terns Sterna hirundo and Sandwich Terns Sterna sandvicensis decreased significantly with increasing windspeed. Capture success did not change but the birds reduced the rates at which they attempted to capture prey. Changes in wave amplitude were probably more important in this than windspeed per se. At low tide when preying on Crangon vulgaris the capture success of Common Terns also decreased significantly with increasing windspeed. Capture methods employed by both species changed in relation to windspeed such that shallower dives were made at higher windspeeds. It is argued that as windspeed and wave amplitude increase the birds find it more difficult to predict the position of the fish below the surface and thus opt to prey mainly on fish nearer the surface. |
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