Low body mass of juvenile Ross's gulls Rhodostethia rosea in the Laptev Sea

Abstract:
Four juvenile Ross's gulls Rhodostethia rosea were trapped on the New Siberian Islands in the Laptev Sea in early August 1994, allowing data collection on body mass and morphometrics from a poorly known part of the species' annual cycle. The wings of juvenile birds were shorter than those previously reported for adults, but their bill length and tarsus length were similar. Their average body mass (128 g) was very low, suggesting that some juvenile Ross's gulls have only very small energy reserves left after post-breeding dispersal, which in this case was at least 300 km.