A comparison of autumn migration strategies in robins<i>erithacus rubecula</i>at a coastal and an inland site in southern Sweden

The biometrics, age ratio and timing of migration of Robins were compared during autumn migration at an inland and a coastal site 200 km apart. The proportion of adult birds was higher at the inland site. The time of peak of migration differed between the two sites by 9 days. The daily distribution showed that at the coastal site the birds made a land‐fall at dawn, while at the inland site the migration continued during the morning. Robins in the same visual fat class were heavier at the inland site, but their mean fat class was lower than at the coastal site. This would be expected if Robins inland were short‐stage migrants and therefore do not need extensive fuel reserves. At the coastal site a higher proportion of the Robins are probably long‐stage migrants. The orientation of the Robins under clear skies was more south‐westerly at the coastal site. The direction is significantly different from the mean azimuth of sunset at the coastal site only. Under totally overcast conditions the directions were more scattered at both sites, indicating the importance of visual cues for orientation.