Assessment of Heavy Metals in Agroecosystems of the Cauvery Delta Region, South India Using a Focal Species: The Pavo cristatus

Agro-ecosystems along the Cauvery delta region, South India are Protected Agricultural Zones that provide suitable habitats for migratory and threatened species of birds. This region has been enduring ecological impacts linked to the extensive use of systemic pesticides and bioaccumulation of heavy metals and other contaminants. The present study evaluated the concentrations of heavy metals (Zn, Pb, Cu, Fe, Mn, Cr, Cd, Ni, and Co) in feathers of Pavo cristatus from the paddy fields and its variations within the different segments (vanes and shaft) of the tail feathers using an Inductively Coupled Plasma-Optical Emission Spectrometry. Our study also recorded the possible sources of contamination and potential risks due to the bioaccumulation of heavy metals in the avifauna that forage these landscapes. The results of the study indicate differential bioaccumulation of heavy metals in different segments of the tail feathers with consistently higher concentrations in the vanes compared to the shaft. Cd, Ni, and Co both in the vanes and shaft were recorded at BDL. The BDL values for Pb in the shaft reveal a lesser affinity of this element to the unpigmented segments of the tail feathers. The results indicate significant interspecific antagonistic associations between Zn–Cr. Multivariate analysis revealed dynamic modes of variability for metals such as Zn, Pb, Cu, Cr indicating higher exogenous contamination. The study reveals vanes as ideal bio-specimens compared to the shaft for environmental monitoring and evaluating trophic biomagnification. Overall, the elemental deposition of metals indicates a lower risk to the species and the environment.