**Abstract**

The purpose of this study is to provide a comprehensive summary of the major functions of avifauna as bioindicators of contamination and their impact on conservation. Birds have been utilised as bioindicators of contamination globally for a long time. When their functions and numbers are taken into account, bioindicators—species that are used to assess the health of the environment—are capable of evaluating the integrity of the ecosystem. Birds are excellent indicators because they are very noticeable and their existence is simple to spot in any setting. They are also equipped with the ability to fly, so they may flee from an environment if it does not meet their ecological needs. In addition, due to their widespread distribution, individual species are simple to recognise in classification. When their functions and numbers are considered, bioindicators can evaluate the integrity of the ecosystem. Birds are excellent indicators since they are simple to spot and observe in any environment. Although necessary for life, heavy metals can be harmful at high levels and disrupt behaviour and productive function. They can also be easily ingested and biomagnified through food or the food chain. Therefore, the use of birds as bioindicators depends on the features of interest and the resources available for ecological evaluation, which encourages the conservation of bird species for the next generation.

**Keywords:** birds, environment, heavy metals, bio-indicators, pesticides
