Feeding ecology of two wintering geese species at Poyang Lake, China

The feeding ecology of the swan goose (Anser cygnoides) and the white-front ed goose (A. albifrons albifrons) overwintering at Poyang Lake, the largest freshwater lake in China, was studied from 1990 to 1991. The daily pattern s of these geese showed differences of the activity categories between spec ies. The energy intakes of these geese were estimated by fecal analysis, da ily dropping counts, and calorie determinations. The average daily digestib le energy intakes of these geese were about twice their basal metabolic rat e. Roots of Vallisneria asiatica, Acorus calamus, and Cates sp. were the ma in food for the swan goose. The leaves of Carer sp. were the main food of t he white-fronted goose. The diets of the geese do overlap with those of som e other waterbirds, mainly that of the Siberian crane (Grus leucogeranus) i n Poyang Lake. This, however, is not a main reason for the decrease of the number of geese in winter in this season.