Influence of Anthropogenic Noise Pollution on Communication Mating Success and Nesting Behaviour of Urban Songbirds

Abstract

Urban noise pollution is a key ecological challenge that impacts bird communication and reproduction by changing the acoustical environment needed for effective communication. The aim of this study is to investigate the effect of urban noise on the vocal communication, mating success, and nesting behavior of songbirds in three types of habitats (low noise, moderate noise, and high noise).                     Urban–peri-urban gradient was considered in the study, which involved common urban songbirds like sparrows, bulbuls, mynas, robins, and tailorbirds. The level of noise was recorded using sound level meters, and bird vocalizations were recorded during the peak morning activity. Observations of behavior were made for pair formation, courtship display, initiation of nesting, clutch size, feeding visits, hatching success, nest abandonment, and fledging success. The results demonstrated a distinct increase in background noise level from low noise areas to high noise traffic and trade areas. Higher noise levels induced songbirds to sing more often, louder, and earlier in the morning, but didn't affect songbird frequency. Higher noise levels caused songbirds to sing louder, more often, and at earlier times in the morning, but did not affect the frequency of song. But these changes in voice did not completely counteract the reproductive disruption. The number of pairs formed, courtship attempts, nesting attempts, hatching success, nest success, fledging success, and nesting success were decreased in high-noise habitats. The findings suggest that urban songbirds are flexible in their behavior,                      but chronically disturbed individuals can reduce their breeding success, parental care, and mating signals. The study raises awareness that urban soundscape management, quiet green spaces, vegetation buffers, and limiting traffic noise in nesting areas are necessary. Ensuring the good quality of acoustic habitat is critical to maintaining songbird populations and enhancing urban biodiversity conservation.