Site Fidelity in High Arctic Breeding Waders

Summary Tomkovich, P.S. & Soloviev, M.Yu. 1994. Site fidelity in High Arctic breeding waders. Ostrich 65:174-180. The return rate and fluctuations in density between years were determined for colour-marked populations of Grey Plover Pluvialis squatarola. Little Stint Calidris minuta, Curlew Sandpiper C. ferruginea, Sanderling C. alba and Knot C. canutus in a study in the Knipovich Bay area, northern Taimyr, Central Siberia (76°05'N. 98°32'E) during three breeding seasons, June 1990 to August 1992. No birds marked as chick were recorded as returning to the study area. Females of all species exhibited low site fidelity. The return rate of males varied between species. No marked male Curlew Sandpiper or Little Stint were recorded in the season following the marking, which is compatible with the nomadic behaviour of these two species. In contrast, males of Grey Plover and Knot were site faithful and had return rates of 78% and 8% respectively (though the latter value may have been underestimated). Site fidelity of Sanderling males lay between these extremes (the return rate was 20%). The variability of bud breeding density in the stud area was negatively correlated with return rate and reached the largest value in Little Stint (a factor 07 18.0 between the lowest and highest densities) and Curlew Sandpiper (factors of 4,4 for males and 5,7 for females), being intermediate in Sanderling (2,5) and the smallest in males of Grey Plover (1,Z) and Knot(1,4). In the late and cold season of 1992, bird densities were smallest in all ses and the largest proportion of site faithful, but unmated, males of Grey Plover and Knot were recorded. Species with highly opportunistic and comparatively conservative territorial connections can be recognise among Siberian High Arctic waders. All species appear to show some degree of opportunism, which is probably dictated by a number of factors of which climate is the most important.