title: Influence of taxa, trophic level, and location on bioaccumulation of toxic metals in bird's feathers: a preliminary biomonitoring study using multiple bird species from Pakistan.
abstract: Increasing concentrations of heavy metals in the environment and their effects on ecosystems and biota is still an imminent threat, particularly in developing parts of the globe. The aim of the present study was to screen the heavy metal concentrations in multiple bird species across Pakistan and to preliminary evaluate the influence of taxa, trophic level, and geographical location on heavy metal accumulation in various bird species. For this purpose, we measured the concentration of 9 heavy metals (Pb, Cd, Cr, Ni, Co, Cu, Fe, Zn and Mn) in feathers of 48 bird species from different localities in Pakistan. Species exhibited heterogeneous levels of heavy metals in feathers with marked inter and intra specific variations. Mean concentrations of studied metals in feathers followed the trend Fe>Zn>Cu>Pb>Mn>Cr>Ni>Co>Cd. Species belonging to closely related taxa (families) showed comparable metal concentrations in their feathers, inferring potential phylogenetic similarities in metal exposure or accumulation. In general, concentrations of metals were greatest in carnivorous species followed by omnivorous and insectivorous birds, and granivores showing minimal levels (p<0.000). Furthermore, concentrations of metals varied significantly between locations (p<0.000) exhibiting highest concentrations in Punjab province and Baluchistan, probably due to higher industrial and agricultural activity and runoff, respectively. With certain limitation, influence of trophic level, taxonomic affiliation and sampling location of birds on toxic metal accumulation was also statistically corroborated through principal component analysis (PCA). This study highlights that despite restricted emissions, heavy metals persist in the local environment and may pose elevated risks for the studied bird species in Pakistan.
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-e-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Naeem Akhtar
authors.initials: NA
authors.lastname: Abbasi
authors.affiliation: Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Veerle Leontina Bernard
authors.initials: VL
authors.lastname: Jaspers
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-e-Azam University, Islamabad, 45320, Pakistan; WWF - Pakistan, Ferozpur Road, P O Box 5180, Lahore 54600, Pakistan.
authors.forename: Muhammad Jamshed Iqbal
authors.initials: MJ
authors.lastname: Chaudhry
authors.affiliation: Department of Wildlife Management, PMAS Arid Agriculture University Rawalpindi, Pakistan.
authors.forename: Sakhawat
authors.initials: S
authors.lastname: Ali
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-e-Azam University, Islamabad, 45320, Pakistan. Electronic address: r_n_malik2000@yahoo.co.uk.
authors.forename: Riffat Naseem
authors.initials: RN
authors.lastname: Malik
mesh_terms: D000818:Animals; D001717:Birds; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D005241:Feathers / Q000737:chemistry*; D020387:Food Chain; D019216:Metals, Heavy / Q000032:analysis*; D010154:Pakistan; D010802:Phylogeny
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy
keywords: Bioaccumulation; Principal component analysis; Taxonomic affiliation; Toxic metals; Trophic level