Research Paper

Exploring avian bycatch from a nationwide camera-trap monitoring program in Taiwan: Community composition, data completeness, and monitoring potential

Ze-En Lai, Yi-Tzu Hsiao, Guo-Jing Weng, Jian-Nan Liu, Jo-Szu Tsai

Published on: 06 August 2026

Page: 621 - 631

DOI: 10.6165/tai.2026.71.621

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    Abstract

    Camera-traps are increasingly used for long-term monitoring of terrestrial mammals, yet they also generate extensive avian bycatch data that remain underutilized. Here, we explore the potential of avian bycatch from large-scale, long-term camera-trap monitoring in Taiwan to characterize terrestrial bird community composition, evaluate sampling completeness, and assess its utility for ecological monitoring. Using data collected from 2015 to 2023 across elevational and seasonal gradients, we summarized species occurrence patterns, relative abundance indices, and diversity metrics based on Hill numbers. A total of 102 bird species or species groups were recorded from over 36,000 independent detection events, with species richness varying across elevations but showing relatively limited seasonal differences. Rarefaction and extrapolation analyses indicated that species richness (q = 0) did not reach asymptotes, reflecting incomplete detection of rare, arboreal, and canopy-associated species, whereas diversity estimates emphasizing common and dominant species (q = 1, 2) converged consistently across seasons and elevations, despite uneven sampling effort across elevational zones. As a species-level illustration, Malayan Night-Heron (Gorsachius melanolophus) case study demonstrated how camera-trap bycatch can provide valuable spatial, temporal, and behavioral information for cryptic, ground-associated birds that are not consistently detected in conventional forest surveys. Overall, our results show that avian bycatch from a large-scale, fixed-location camera-trap monitoring program offers a complementary data source for understanding terrestrial bird communities, particularly for dominant and ground-dwelling taxa. Given the long-term continuity of this government-operated monitoring program, continued accumulation and integration of avian camera-trap bycatch data hold substantial promise for future ecological research and biodiversity monitoring.

    Keyword: Avian camera-trap bycatch, camera trapping, community composition, elevational gradient, long-term monitoring

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