Extreme head-tilting in shorebirds: predator detection and sun avoidance
Info
Pages
18 – 21
Published
1 April 11
Authors
Piet J. van den Hout, Graham R. Martin
Correspondence
Piet van den Hout
piet.van.den.hout@nioz.nl
Department of Marine Ecology and Evolution, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
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Public Files
We report observations on extreme head-tilting behaviour in two shorebird species, Baird’s Sandpiper Calidris bairdii and Puna Plover Charadrius alticola foraging at midday, and under a clear sky, on a salt plain in Chile. From the viewpoint that careful interpretation of head postures is essential when studying anti-predation vigilance of foragers, we discuss whether such head postures may be a manifestation of a particular type of vigilance behaviour, whose primary function is the detection of predators in the sky, and/or the avoidance of disability glare produced by imaging the sun on the retina, which generally reduces image quality across the entire visual field.