Daily energy expenditure of Great Cormorants Phalacrocorax carbo sinensis wintering at Lake Chiemsee, Southern Germany.

In the winters of 1993/94 and 1994/95 the daily energy expenditure (DEE) of Great Cormorants Phalacrocorax carbo sinensis was measured using the doubly labelled water technique (DLW). This was the first time the method has been used on a Phalacrocoracid species. DLW trials were carried out on 5 caged birds and on 5 free-ranging wild birds at Lake Chiemsee. The mean body mass of the captive birds (2079 g) was not significantly different from and that of wild birds (2122 g). There was no significant difference in the total body water (TBW) of the two Cormorant groups (55.9% in captive birds and 56.7% in free-ranging birds). Estimated DEE (