The diet of wintering waders in Cádiz Bay, southwest Spain

Abstract

In Cádiz Bay, southwest Spain, salt pans and fish ponds in the saltmarshes provide an important additional source of food to intertidal flats for many waders (Charadrii) during the winter. As little is known about the diet of waders in Spain in general, and in saline ponds in particular, droppings and pellets produced by waders were collected from the ponds and mudflats, and analysed for the remains of prey. Direct observations of feeding birds were also made. The diets of Redshank Tringa totanus, Grey Plover Pluvialis squatarola, Curlew Numenius arquata, Black–tailed Godwit Limosa limosa, Bar–tailed Godwit Limosa lapponica, Ringed Plover Charadrius hiaticula, Kentish Plover Charadrius alexandrinus, Black–winged Stilt Himantopus himantopus, Dunlin Calidris alpina, Little Stint Calidris minuta and Sanderling Calidris alba were investigated in this way, with particular attention being paid to the saline ponds. Compared with the results from studies made in the winter in northern Europe, many of the waders in the Bay took many insects and, surprisingly, also the seeds of saltmarsh plants.