Abstract:

Aim: Traditional bird diversity surveys have largely relied on manual observations; however, in recent years, voiceprint monitoring technology has been gradually applied, providing a new approach for studying avian diversity. Avian diversity is a key indicator for assessing the quality of wetland ecosystems. This study aims to compare AI-based voiceprint monitoring with manual transect surveys, offering a case reference for the application of bird voiceprint monitoring devices in wetland parks nationwide. 

Methods: In January (winter), April (spring), August (summer), and October (autumn) of 2024, this study conducted comprehensive and systematic bird diversity surveys at five sites within Xixi National Wetland Park in Hangzhou, Zhejiang, where manual transect surveys and voiceprint monitoring devices overlapped. The voiceprint monitoring uses a confidence threshold of 77.5% for output data. Based on Simpson dominance index (C), Shannon-Wiener diversity index (H′), Pielou evenness index (J), and Margalef richness index (M), the applicability and limitations of two methods were evaluated. 

Results: (1) Across the four seasons, voiceprint monitoring detected 105 species, while manual transect surveys recorded 89 species; voiceprint monitoring showed better performance in species richness (S). (2) In terms of residency status, voiceprint monitoring showed higher detection efficiency for migratory and passage birds, whereas manual transect surveys performed better for resident birds; moreover, voiceprint monitoring contributed new regional records. (3) The seasonal variations of the indices obtained by the two methods were not entirely consistent. (4) By region, the highest H′, J, and M values under voiceprint monitoring were observed at Lüdi/Shuixiachanglang area, whereas under manual transect surveys, the highest values were recorded at Lianhuatan area. 

Conclusion: Overall, voiceprint monitoring is suitable for long-term and wide time-scale dynamic monitoring, with broad application prospects, and can serve as a complement to manual transect surveys. An evaluation system incorporating recognition confidence and quality control thresholds is recommended to enhance the accuracy and comparability of the method.

Key words: avian diversity, voiceprint monitoring, manual transect, wetland, Hangzhou Xixi