The detailed methods of data collection and history data of Changxing population from Male density, a signal for population self-regulation in <i>Alligator sinensis</i> ZhaoLan FangLi-Ming WanQiu-Hong FangSheng-Guo 2019 Supplementary methods S1: The methods related with number count, incubation, identification of fertilised eggs, sex, and age, and data selection. Supplementary table S1: The population events and breeding situation in each of the evaluated years. Supplementary table S2: The calculated age structure of the Chinese alligator (Alligator sinensis) sub-population in areas C and C1.