Changes in the body composition of Velvet Scoters (Melanitta fusca) wintering in the Gulf of Gdańsk

Abstract

Body mass and body composition of 27 adult Velvet Scoters (Melanitta fusca) were studied. These birds were collected from January to March in the Gulf of Gdańsk, Poland. Body mass, fat, and protein contents of both males and females decreased significantly between mid and late winter, possibly because of a physiological process or a result of worsening environmental conditions. In mid-winter, the mean body mass of males and females did not differ significantly, whereas in late winter the difference in body mass between sexes became prominent. There was no difference in fat mass between the sexes, but females had higher lipid indexes despite their smaller size. The lack of expected fat mass increase in late winter may be due to the spring migration strategy of Velvet Scoters, which apparently opt to fly short distances rather than make long non-stop flights after departure from the Gulf of Gdańsk. Body mass was the best predictor of fat mass accumulated by Velvet Scoters wintering in the Gulf of Gdańsk.

Body composition dynamics of common eider during winter: An application of the deuterium dilution method

“…The decrease in wet lean mass of female American common eiders during late winter that we documented was not observed in the northern subspecies (Milne , Jamieson et al ), whereas all studies of common eider to date detected that wet lean mass of males did not change during winter (Milne , Jamieson et al , our study). Loss of wet lean mass during winter has been observed in other waterfowl (Ballard et al , Meissner et al ) and may be related to local environmental conditions and different migration or breeding strategies. However, given that the late‐winter decrease in wet lean mass of females in our study was sensitive to the inclusion of one very lean female, we encourage cautious interpretation of this pattern, and further study.…”

Estimation of fat reserves of Robins (Erithacus rubecula) migrating through the southern coast of the Baltic Sea in spring

“…To overcome this limitation, alternative approaches based on the predictive equations have been proposed. Since such approaches require a sufficient sample of fresh carcass, such equations are available just for a few species of passerines (Carpenter et al 1993, Wojciechowski et al 2014, waders (Castro & Myers 1990, Piersma & Brederode 1990) and ducks (Meissner et al 2012).…”