Effects of Artificial Light and Urbanization on Nesting Success Foraging Efficiency and Predator Avoidance in Urban Birds

Abstract

Urbanization and artificial light at night are significant environmental stressors that have a major impact on wildlife ecology, especially in birds. This study was undertaken to assess the impact of artificial light and urbanization on nesting success, foraging efficiency, and predator-avoidance behavior in urban birds. The study also examined adaptive species-specific responses to urban environmental disturbances. A quantitative ecological field-based observational study was carried out throughout the urban, suburban, and semi-natural areas in order to cover different levels of urbanization and light at night. Urbanization intensity was evaluated by environmental indicators (building density, vegetation cover and traffic activity), and the intensity of artificial light was measured by digital lux meters. The success of nesting was assessed based on hatchability, chick survival, and nest abandonment rates. Direct behavioral observations were used to analyze foraging efficiency and predator avoidance behavior. Ecological data were subjected to statistical analyses, including ANOVA, regression, and correlation. The results showed that higher intensities of artificial light reduced the reproductive success of urban birds. Hatchability rate dropped from 88% in areas of low urbanization to 61% in highly urbanized areas, and chick survival rate dropped from 84% to 55%. Strong illumination during the night resulted in a rise of nest abandonment from 6% to 27%. Prey capture success decreased while feeding duration increased with urbanization, from 82% to 53% and 95 min/day to 146 min/day, respectively. In highly urbanized areas, the frequency of vigilance dropped from 19 to 9 events/hour and the predator escape response time rose from 2.4 to 5.7 seconds. The study provides compelling evidence that human-made light and urbanization can exert much ecological pressure on urban bird populations, disrupting their reproduction, feeding habits, and anti-predator responses. Protecting urban avian biodiversity requires urban planning for sustainability, controlled lighting systems and conservation-oriented habitat management.