Abstract: From December 2016 to February 2017 and from December 2017 to March 2018, the scan-sampling technique and focus animal method were used to study energy expenditure and foraging behavior of wintering Tundra Swan (Cygnus columbianus) and Swan Goose (Anser cygnoides) in a lotus habitat near Poyang Lake during the daytime. The results showed that both Tundra Swan and Swan Goose spent their daytime on resting (36.01% vs. 28.02%), foraging (32.71% vs. 17.44%), and locomotion (17.26% vs. 30.61%). Correspondingly, they mainly expended energy for foraging (354.1 vs. 144.88 kJ·d^-1), resting (275.22 vs. 164.35 kJ·d^-1) and locomotion (219.79 vs. 299.22 kJ·d^-1) in daytime. The energy expenditure of foraging behavior and total energy expenditure of Tundra Swan were significantly higher than those of Swan Goose. There was no significant difference in daily energy expenditure between Tundra Swan and Swan Goose. Tundra Swan mainly adopted feeding way from the water surface and dipping with headneck submersed, while Swan Goose used feeding way from the water surface and digging food. This is related to the water depth, food composition, and their own morphology. Tundra Swan and Swan Goose have different foraging methods and foraging water depth to decrease interspecific competition.

Key words: Vicia faba, Root rot, Fungicide, Triadimefon, Seed treatment