**8. Disadvantages of using Avifauna as indicator species in probing heavy metal pollution**


### **9. Conclusions**

High levels of toxicity in some heavy metals can disrupt behaviour and productive function. Lead poisoning can be triggered by the presence of heavy metals, impairing the immune system and harming the nervous system. Birds' ability to reproduce and grow can both be affected negatively by Cadmium. In addition, methylmercury can hinder bird reproduction, resulting in a decrease in egg size, fertility, and hatchability. Once a certain heavy metal's allowable limit is exceeded, the aforementioned impacts of heavy metals on bird species are immediately apparent. As a result, wild birds are good markers of environmental heavy metal pollution. A function of the features of interest and resources available for ecological evaluation, using birds as bioindicators encourages the conservation of bird species for future generations. It is crucial to investigate potential mechanisms through which heavy metals may be to blame for the development of illnesses in wild birds. This will most certainly support the protection of threatened and endangered bird species.

### **Acknowledgements**

The author is thankful to the Department of Environment Sciences, GITAM Institute of Science for providing basic infrastructure, library, and technical support and to the University Grants Commission (UGC) Rajiv Gandhi National Fellowship for funding the current work.

### **Conflict of interest**

The authors declare no conflict of interest.
