Wind effects on habitat use by wintering waders in an inland lake of the Iberian Peninsula

Abstract

We aimed to identify the effects of the direction and wind speed on feeding habitat selection of wintering dunlins and little stints in an inland lake of the Iberian Peninsula. Feeding habitat (muddy surface or shallow water) and location in the lake with respect to wind direction (windward and leeward) of feeding flocks of both species were assessed on days with different wind speed (light or strong). We also performed visual counts of potential prey items (zooplankton) in mud and water habitats. In light wind conditions, wader flocks mostly selected the shallow water on the lake’s leeward shore. On the contrary, in strong wind conditions, the birds tended to forage on the windward shore, with a similar frequency in mud and shallow water habitats. The abundance of prey items in the mud and water column varied according to wind conditions, being higher in the sites preferred by waders. Our findings advance knowledge on how small–sized waders cope with environmental dynamics of wind in non–tidal lakes.