Passive acoustic monitoring reveals how urban vegetation supports acoustic refuges for avian communication in a subtropical megacity

Urbanisation fundamentally alters the sensory landscape, creating novel acoustic environments where anthropogenic noise acts as a rigorous filter on wildlife communities. While birds are known to adjust their songs to cope with noise, the limits of this plasticity and the role of fine‐scale habitat structure in buffering these constraints remain poorly understood, particularly in intensely urbanised megacities. Understanding these acoustic adaptations is essential for revealing the mechanisms of urban community assembly. We established a synchronised passive acoustic monitoring (PAM) network across 21 urban parks in Shenzhen, China, to monitor a sentinel species, the Common Tailorbird ( Orthotomus sutorius ). Integrating deep learning for soundscape decomposition and Terrestrial Laser Scanning (LiDAR) for 3D habitat quantification, we analysed vocal adjustments across continuous environmental gradients. We found that O. sutorius exhibits complex, context‐dependent plasticity based on the Bayesian linear mixed models (BLMMs) results. Birds showed broader bandwidth under continuous traffic noise but reduced vocal output during pulsed anthropogenic events. Crucially, generalised additive models (GAMs) indicated that habitat structure was associated with non‐linear variation in these responses, with fitted transition values in understorey vegetation density and horizontal aggregation marking conditions consistent with stronger acoustic refuge effects. Synthesis and applications . Our findings suggest that green infrastructure should include sufficient structural complexity to transition from mere visual cover to functional acoustic refuge. We recommend that urban planners and park managers: (a) retain functional vegetation complexity rather than remove it for neatness; (b) emulate natural, clumped planting designs rather than uniform spacing to support quiet micro‐refugia for birds; (c) design greenspaces with high core proportion and plant dense vegetation buffers along corridors; (d) implement temporal zoning for high‐decibel maintenance during breeding seasons. These quantitative baselines provide a pathway for designing acoustically resilient cities that facilitate human‐wildlife coexistence.