Time budgets provide important information for the study of animal behavior. The present study analyzed the daily travel distance, home range and group characteristics of scaly-sided merganser Mergus squamatus in Yihuang and Wuyuan counties, Jiangxi Province, China, from December 2012 to March 2013 and December 2015 to March 2016. Results showed that the daily travel distance of scaly-sided merganser was 3100 ± 1313 m; the daily home range was 122,460 ± 42,019 m2; and the overall home range was 202,350 m2 during the wintering period. No significant difference was detected in the daily travel distance between different months (F = 0.658, P > 0.05). Significant differences were detected in the daily home rang between January and February, and between February and March. No significant correlation was observed between daily travel distance and home range (R = 0.256, n = 12, P > 0.05). The significant correlation between daily home range and daily minimum temperature may be related to energy requirements or prey activities. The average group size of the scaly-sided merganser was 3.91 ± 2.94 individuals, and extremely significant differences existed at different time of day (F = 25.540, df = 11, P < 0.01). The largest group size (5.22 ± 5 individuals) appeared at 16:00–17:00, and the smallest at 08:00–09:00 (2.6 ± 1.12 individuals), similar results obtained between December 2015 and March 2016, which was related to the daily habits of this species, such as dispersed foraging, collective maintenance and rest. Group size peaked in February (5.07 ± 4.166 individuals) and was smallest (2.91 ± 1.354 individuals) in December with significantly different group sizes in all months (F = 35.351, df = 3, P < 0.01). A total of 57.98% of all groups had a majority of females. A large difference in sex ratios was observed among different months. The actual ratio of [(adult + sub-adult male): (adult + sub-adult female)] was 1:1.44 (n = 22) in February. Future studies are necessary, and the main goal should be focused on sex ratio, mortality and sex ratio at birth.