First insight into levels, spatial, and gender-specific distribution of potentially toxic elements in black kite, Punjab, Pakistan

This study was intended to quantify the bioaccumulation of potentially toxic elements (PTEs) in black kites to provide indirect information about the extent of contamination of their habitats. In eight elements, concentrations of lead (Pb), manganese (Mn), and copper (Cu) were higher than those recommended for raptors, while nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), and cadmium (Cd) were within the recommended range. We detected higher levels of Ni, Co, Mn, Fe, and Zn from northern Punjab, Cu, and Cd from central Punjab, while Pb in southern Punjab. Furthermore, the distribution of Pb, Ni, Co, Fe, and Cd among regions of Punjab was highly significant (p < 0.05); however, it was non-significant (p > 0.05) for Mn, Cu, and Zn. These elements showed following descending order of concentration levels: Fe > Zn > Cu > Mn > Pb > Ni > Co > Cd. A significant correlation (p < 0.05) was observed between the body weight and Mn whereas non-significant (p > 0.05) with all other PTEs. In addition, the route of the exposure of most PTEs showed significant differences (p < 0.05), and for most PTEs, it was observed higher in the liver followed by kidneys, muscles, and feathers. Moreover, the bioaccumulation of most of the PTEs was gender-independent. As a result, black kites exhibited moderate to subclinical toxicity levels which may have significant effects on the population growth, reproduction, and abundance in Punjab, Pakistan.