Blood lead levels for Eurasian black vultures (Aegypius monachus) migrating between Mongolia and the Republic of Korea

Metal Contents in Feathers from Birds (Rhynchopsitta terrisi, and Columba livia) with Different Ecological Niches

The metal contaminants can be utilized as an ecological tool to analyze niche partition in birds. As environmental contamination biological indicators, essential (Zn, Cu, and Cr) and non-essential (Pb and Cd) metals in the flight feathers of the Maroon-fronted Parrot and Pigeon with different ecological niches were assessed. The feathers of the parrot were gathered at a national park (Parque Nacional Cumbres de Monterrey) and the feathers of pigeons were collected at an urban site, that is, the city of Monterrey, Mexico. An atomic absorption spectrophotometer was used to establish the concentration of metals in the feathers. Zn, Cu, Cr, Pb, and Cd were detected in the two studied samples. The results obtained in this study exhibited an increase in metal concentrations in pigeon feathers with respect to parrot feathers. In conclusion, employing parrot and pigeon feathers comprises an important tool to track trace-metal occurrence in the environment and metal accumulation in birds. This information is crucial to possess in order to minimize exposure to essential metals in species of wild birds with different ecological niches.

High Levels of Heavy Metals detected in Feathers of an Avian Scavenger Warn of a High Pollution Risk in the Atacama Desert (Chile)

The Atacama Desert represents the highest levels of mining exploitation in Chile, which inexorably results in high levels of pollution. Raptors, and particularly scavengers, have shown their usefulness to evaluate exposure to environmental contaminants in polluted scenarios. In this study, we used primary feathers from a local avian scavenger, turkey vulture Cathartes aura, to evaluate the exposure to cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn) in two locations from the southern Atacama Desert (coastal and inland) and a third location from the bordering semiarid region, in northern Chile. All metals were detected in all analyzed samples (n = 54). Mean concentrations in Coastal Atacama were 0.68 ± 0.84 ppm for Cd; 1.97 ± 2.01 ppm for Pb; 59.11 ± 80.69 ppm for Cu; and 107.96 ± 51.00 ppm for Zn, while mean concentrations in Inland Atacama were 0.55 ± 0.42 ppm for Cd; 3.37 ± 2.61 ppm for Pb; 91.66 ± 77.74 ppm for Cu; and 214.03 ± 99.08 ppm for Zn. Mean concentrations in Coastal Coquimbo were 0.63 ± 0.69 ppm for Cd; 1.57 ± 0.92 ppm for Pb; 18.09 ± 6.12 ppm for Cu; and 149.37 ± 105.56 ppm for Zn. These differences could be explained by differences on abundance of mining settlements among areas. According to the literature, these values are very high for all metals, exceeding in some cases those values referred as responsible of health disorders in birds. We strongly recommend further research looking at potential adverse effects caused by heavy metal pollution on the health of human and wildlife populations in the southern Atacama Desert.

Completing a worldwide picture: preliminary evidence of lead exposure in a scavenging bird from mainland Australia

Lead toxicity from ammunition has been shown to be a threat to scavenging birds across the globe. Despite decades of research in Europe, North and South America, Asia and Africa, there have been no studies to investigate this phenomenon in Australia despite that continent having many species of scavenging birds and widespread shooting practices. We present preliminary evidence of lead exposure in Australia's largest bird of prey, the wedge-tailed eagles (Aquila audax) through analysis of bone and eggshell samples from south-western Australia. From 11 bone samples, three birds (27%) had lead levels exceeding literature thresholds for elevated levels (>6.75 ppm). From 36 eggshell samples, no samples had lead levels >0.5 ppm, suggesting some limitations for this matrix as an indicator of lead exposure. Isotope ratios suggested ammunition as a likely source of the lead found in bone samples with elevated lead levels but other potential sources of lead require further investigation. Our preliminary results demonstrate that lead exposure is occurring in scavenging birds in Australia, and like the rest of the world, is likely to be derived from ammunition. This study supports an urgent call for further research into this worldwide phenomenon in Australia.

What do we know about lead contamination in wild vultures and condors? A review of decades of research

Vultures and condors (hereafter vultures) make up one the most threatened avian guilds in the world due to a variety of human-mediated impacts and disturbances. In fact, 70% of vulture species are currently suffering impacted by significant conservation threats, with lead contamination being particularly important. Unfortunately, lead contamination in vulture species remains poorly studied in many regions of the world. We reviewed the existing scientific knowledge about this threat to vultures. We found 62 scientific articles studying lead contamination in vultures. Seventy-two percent of these articles were from North America and Europe, with the rest corresponding to Asia (13%), South America (8%), and Africa (7%). Most (92%) were published recently (2001-2018). Published articles included information on 13 vulture species out of a total of 23 from both the Old (9) and New World (4). Eighty-eight percent of the articles showed individuals with lead concentrations above threshold levels in some tissues sampled, with New World (Cathartidae) vultures more affected than Old World vultures (Accipitridae). The most suspected but rarely probed source of lead was lead ammunition, but other sources such as pollution or industry were also reported. It is concerning that lead contamination is considered a major threat for just 8% (2/23) of the vulture species categorized by the IUCN Red list. Our review shows that lead contamination is an important threat for several vulture species worldwide, but remains undiagnosed and not well-recognized in some species and geographical areas. The effect of this contaminant on vulture demography is not well known but merits particular attention since it may be leading to population declines in several species.