Abstract:

Aims: To enable objective comparison of hornbill reproductive behaviors and facilitate in-depth research on their ecological evolution, this study was conducted from February to July 2023–2024 in the Tongbiguan Provincial Nature Reserve, Yunnan Province. Specifically, we aimed to systematically document the behavioral characteristics of three sympatric hornbill species—the Oriental Pied Hornbill (Anthracoceros albirostris), the Great Hornbill (Buceros bicornis), and the Wreathed Hornbill (Rhyticeros undulatus)—and to construct an ethogram for each, thereby providing foundational data for subsequent research. 

Method: Field observations and video recordings were used to systematically collect data on the reproductive behaviors of the three hornbill species. Basic behavioral data were compiled to construct an ethogram for each species. These ethogram were then integrated to establish a posture-act-environment (PAE) coding system, enabing standardized classification and quantitative description of behaviors. 

Results: The results showed that the Great Hornbill and Wreathed Hornbill both exhibited 7 postures, 34 acts, and 6 environmental variables, whereas the Oriental Pied Hornbill had 6 postures, 29 acts, and 6 environmental variables. The integrated PAE coding system comprised 7 posture categories and 39 distinct behaviors. Among the three species, the Wreathed Hornbill exhibited the highest total number of behaviors (39), followed by the Great Hornbill (38), and the Oriental Pied Hornbill (26). Statistical analysis indicated no significant differences in behavioral diversity indices among the three species, nor were there significant differences in any diversity index between sexes within each species. 

Conclusion: The ethogram and PAE coding system established in this study provide a detailed behavioral inventory and quantitative description for these three endangered hornbill species, offering essential baseline information for subsequent behavioral ecology research and conservation management.

Key words: Anthracoceros albirostris, Buceros bicornis, Rhyticeros undulatus, ethogram, PAE coding system, behavior diversity