LAUSR

A wide variety of substances and agents are released into the atmosphere due to anthropogenic activities. Higher levels of such entities have given rise to four major environmental problems: air, light and noise pollution and global warming, all of which severely affect birds and other animals. These four issues have been overlooked, although climate change is receiving increasing attention. The four challenges often occur simultaneously and are likely to exert composite impacts. Most studies have focused on the effects of a specific problem at a particular time and have never taken into account their cumulative consequences. This review tries to address this shortcoming. It aims to evaluate the composite impacts of the problems on flying birds beyond an understanding of their individual impacts. The review initially sheds light on the individual impacts based on existing scientific literature. Composite impacts were then estimated by assigning suitable scores to the literature to convert it into empirical data. Scores were then analysed. Through this assessment, it was found that the health of birds is highly vulnerable to the composite effects of the problems. Additionally, statistical analysis revealed that the effects of all problems on different aspects of avian biology are likely to be magnified simultaneously in the future. Thus, the impact of these problems on birds should not be neglected, and further studies should be conducted to understand their mechanisms.