Birds serve as key indicators of environmental health, helping to monitor and maintain ecological balance. The study conducted from 2021 to 2024 in the Karaivetti Bird Sanctuary, located in the Ariyalur district, aimed to assess year-wise species diversity, richness, relative diversity, evenness, density, and relative abundance of wetland birds. The total count method was employed to estimate the population of wetland birds. The study at Karaivetti Bird Sanctuary recorded 97 bird species over four years, with 30 migrant and 67 resident species. Among these, five species were Near Threatened viz., Black-tailed Godwit (Limosa limosa), Woolly-necked Stork (Ciconia episcopus), Spot-billed Pelican (Pelecanus philippensis), Black-headed Ibis (Threskiornis melanocephalus) and Oriental Darter (Anhinga melanogaster) and two were Vulnerable viz., Greater Spotted Eagle (Clanga clanga) and Common Pochard (Aythya ferina). Comparative studies in other sanctuaries revealed similar patterns in species diversity and abundance. The highest species diversity at Karaivetti was in 2021, while the highest richness occurred in 2022. Total bird density was highest in 2021 and lowest in 2024, with the Little Cormorant showing the highest relative abundance in recent years.