2.5 Statistical analyses
We used ANOVA to test for a significant difference in the dietary diversity and composition between different seasons. The frequency of occurrence (the number of pellets containing that foods divided by the total number of pellets in the species sample, FO) and the numbers of foods during different seasons were compared statistically using Dunnett’s T3 multiple comparisons test by SPSS 20.0 software. The Manne−Whitney U test was also adopted to assess the difference in relative abundance of food items between different seasons following our previous study (Tang et al. 2019). Heat maps, box plots and taxa summary bar charts were generated using the “ggplot2” package of R software (Wickham 2009).