Differences in foraging ecology of Wood Sandpiper Tringa glareola and Ruff Philomachus pugnax during spring migration in Sajna River valley (nor thern Poland)

The research was conducted in 2002, in Sajna River valley (NE Poland). It was aimed at foraging ecology of two wader species not specialised in terms of feeding techniques. We found that while foraging on a stopover site during spring migration Ruffs used different ecological niche than Wood Sandpipers. Ruffs foraged significantly more often in medium and deep water and made also more medium and deep probes, what indicates preference in random probing. High intensity and proportionally low efficiency of foraging may confirm it. Contrary, Wood Sandpiper foraged less intensively but much more effectively; this, together with frequent changes of feeding places in terms of water level indicate that Wood Sandpiper to greater extent uses visual detection of prey than Ruff.