MEPS 159:239-247 (1997)  -  doi:10.3354/meps159239

On the German Baltic Sea coast most migrating shorebirds stage in wind flats that are characterized by irregular wind-induced fluctuations of water level. As it had been suggested that large shorebirds cannot fulfil their energetic requirements in wind flats due to the lack of prey organisms large enough to be profitable, we investigated the feeding ecology of curlews Numenius arquata at Hiddensee (July to November 1995). Most prey taken were the largest ragworms Nereis diversicolor present in the sediment (>85 segments), while 2 bivalves contributed 4.2% (Cerastoderma lamarcki) and 0.8% (Mya arenaria), respectively. Most curlews foraged in shallow water where we observed the maximum intake rate (3.5 prey min^-1) compared to exposed flats (2.0 prey min^-1). This is thought to be the result of highest surface activity and therefore best detectability and accessibility of ragworms in shallow water. Prolonged periods of low foraging activity in late morning and around noon as well as the aggregation at night roosts suggest that curlews do not have problems maintaining their energy budget in the study area. This is explained by their ability to find the few most profitable prey organisms available, even though these occur at low density.

Shorebirds · Numenius arquata · Feeding ecology · Wind flats · Baltic Sea · Nereis diversicolor · Mya arenaria · Cerastoderma lamarcki