Preliminary Study on Time Budget and Foraging Strategy of Wintering Oriental White Stork at Poyang Lake, Jiangxi Province, China

The time budgets, behavior rhythms, foraging habitats and food preferences of oriental white stork Ciconia boyciana were studied from December 2013 to March 2014 with instantaneous scan sampling and focus animal sampling methods at Poyang Lake, Jiangxi province, China. The results showed that the main behavior of oriental white stork were resting (40.07±3.21%) and foraging (35.44±2.42%), followed by moving (13.46±1.01%) and preening (9.05±0.62%). The patterns of time budgets were similar in early and later wintering periods. Daily minimum temperature showed a significant linear relationship with foraging and resting. Foraging was significantly positively correlated with daily minimum temperature, and resting was significantly negatively correlated with daily minimum temperature, which indicated that minimum temperature was the key factor affecting stork behavior in winter. Foraging behavior peaked at 7:00–7:59 and 16:00–16:59 hours and resting peaked at 11:00–11:59 hour. Oriental white stork foraging habitats varied in different months and gradually shifted from shallow water to grassland. Their average moving rate was 17.86±0.61 steps/min, pecking rate was 8.31±0.25, and pecking success rate was 1.03±0.04 pecks/min. In shallow water, average pecking rate was significantly positively correlated with moving rate and pecking success rate. In mudflats and grasslands, moving rate was significantly negatively correlated with pecking success rate. We argued that oriental white stork use different foraging methods and prey capture techniques in different habitats, possibly because food resources in mudflats and grasslands differ from those in shallow water. The oriental white stork mainly preyed on fish in shallow water, and it handled large-sized fishes (>15 cm) for 201.07±35.31 sec (n=23), and small-sized fishes (<15 cm) for 85.22 ± 20.86 sec (n=14).