Wader species migrating through the Sivash (Ukraine) use hypersaline and brackish lagoons. We studied the use of the two habitat types, and focused on the profitability of Brine Shrimp Artemia salina, prey species in hypersaline lagoons for Dunlins Calidris alpina, Curlew Sandpipers Calidris ferruginea and Broad-billed Sandpipers Limicola falcinellus (although the latter was abundant in the brackish habitat only). Colour-marked Dunlins restricted feeding to the lagoon type in which they were initially captured. Dunlins and Curlew Sandpipers fed in areas where Brine Shrimps were of average size (0.23-0.34 mg AFDM). Artemia intake may be restricted by the visual foraging mode, as during rain and twilight pecking rates decreased to 45.9-76.8% of values measured during dry periods in full daylight. Feeding activities were higher in hypersaline than in brackish lagoon (84.6 and 69.0%, respectively). Broad-billed Sandpipers feeding on Artemia had longer handling times (0.87 s prey(-1)) than Dunlins and Curlew Sandpipers (0.58 and 0.54 s prey(-1)), which performed surface tension transport (STT) of prey in their pointed, thin bills. There were no differences in body mass increases in Dunlins in hypersaline and brackish lagoons. In Broad-billed Sandpipers, catching results suggest an increase in body mass in the brackish lagoon only. Supported by intake rate-based calculations of potential mass gain rates, we conclude that Brine Shrimp can form a profitable prey for Dunlins and for Curlew Sandpipers, but apparently not for Broad-billed Sandpipers.
|Publication status||Published - 2003|
- dunlins calidris-alpina
- wadden sea
- foraging behavior