Behavioral ontogenetic diversity in juvenile black storks (Ciconia nigra)

The development of behavioral diversity in juvenile animals is closely linked to their environmental adaptability and survival rate. However, research on development of behavioral diversity in juvenile animals remain limited. From May to August 2021, we surveyed three juvenile black storks (Ciconia nigra), a Class I protected species of China, at Zhangye Heihe National Wetland Nature Reserve in Gansu Province, to explore their behavioral ontogeny. We established their behavioral repertoire, and analyzed rhythms and diversity across developmental stages. The research results revealed that behavioral frequency and diel behavioral rhythms differed significantly across months, while time of day and month both exerted notable influences on behavioral differentiation. All behavioral diversity indices presented distinct monthly changes. Behavioral frequency and behavioral counts increased obviously over time, as did the Shannon-Wiener and Simpson's diversity indices. By contrast, the Berger-Parker and Simpson's dominance indices declined significantly with time, and no obvious correlation was detected between time and Pielou's evenness index. Discriminant analysis confirmed clear behavioral differences among developmental stages, with stable and stage-specific behavioral patterns emerging at different periods. Overall, behavioral development in juvenile black storks follows a clear temporal sequence, with environment-adaptive behaviors being progressively expressed as development proceeds. Behavioral ontogeny advances from simple to complex behaviors and from single to increasingly diverse behavioral repertoires.