Spatial Behavior of European Robins During Migratory Stopovers: A Telemetry Study

We studied the movement patterns of European Robins (Erithacus rubecula) at stopovers during spring and fall migration on the southeastern Baltic Coast, Russia. On the 1st, and sometimes the 2nd, day after arrival at a stopover site, robin movements were less aggregated than those made on subsequent days. Search/settling time varied between several hours and 2 days. During this period, migrants either occupied a defined stopover area or left the site. Stopover duration was 1 to 12 days in spring (mean = 2.4 days ± 0.31 SE) and 1 to 14 days in fall (mean = 3.4 days ± 0.50). The home-range size of European Robins on the southeastern Baltic Coast did not differ between seasons (spring: 4,320 m2 ± 545, n = 15; fall: 3,562 m2 ± 598, n = 15) and was similar to that at a central European site in fall (4,264 m2 ± 241, n = 14). These home ranges were not defended territories. We found no relationship between the robins' spatial behavior and their fat stores on arrival, although in spring more lean than fat robins stopped for >2 days. The pattern of movements at the stopover was variable, both in birds that arrived lean and those that arrived with much more fat. Stopover duration estimates based on radio-tagging are superior to those based on capture-mark-recapture.