title: Assessing multi-tissue lead burdens in free-flying obligate scavengers in eastern North America.
abstract: Avian scavengers are regularly exposed to anthropogenic lead. Although many studies evaluate lead concentrations of either blood or tissues of lead-poisoned birds, there is comparatively less research on lead burdens of free-flying, apparently healthy individuals and populations. Here, we address this lack of information by assessing lead levels of multiple tissues (femur, liver, kidney, breast muscle, thigh muscle) in free-flying black vultures (n = 98) and turkey vultures (n = 10) collected outside the hunting season. We found only one individual had a soft tissue lead concentration indicative of acute exposure (6.17 mg/kg wet weight in the liver), while the other 107 vultures showed consistent low-level lead exposure throughout the soft tissues. All vultures, however, had femur lead concentrations indicative of chronic lead exposure (black vultures [Formula: see text]31.80 ± 20.42 mg/kg (±SD); turkey vultures 23.21 ± 18.77 mg/kg). Lead levels were similar in all tissues in both vulture species (in each case, p > 0.05) and were generally highest in the femur, intermediate in the kidney and liver, and lowest in the breast and thigh muscle. Despite the consistency of these patterns, there were few strong correlations between lead levels in different tissues within each species, and those correlations that did exist were not consistent between species. Because these vultures were free flying and apparently healthy, the organism-wide lead distributions and between-species trends we report here provide important insight into the sublethal lead burdens that black vultures and turkey vultures commonly carry. Furthermore, these data offer a framework to better interpret and contextualize lead exposure data collected from these and other species.
authors.affiliation: School of Natural Resources, West Virginia University, PO Box 6125, Morgantown, WV, 26506, USA. sbehmke@mix.wvu.edu.
authors.forename: Shannon
authors.initials: S
authors.lastname: Behmke
authors.affiliation: U.S. Geological Survey, WV Cooperative Fish and Wildlife Research Unit, West Virginia University, Morgantown, WV, 26506, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Mazik
authors.affiliation: School of Natural Resources, West Virginia University, PO Box 6125, Morgantown, WV, 26506, USA.|USDA Forest Service, Northern Research Station, Morgantown, WV, 26287, USA.|U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 970 Lusk St, Boise, ID, 83706, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Katzner
mesh_terms: D000818:Animals; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000378:metabolism*; D046093:Falconiformes / Q000378:metabolism*; D005247:Feeding Behavior; D020387:Food Chain; D007854:Lead / Q000378:metabolism*; D013045:Species Specificity; D014018:Tissue Distribution; D014768:Virginia
chemical_list: D004785:Environmental Pollutants; D007854:Lead
keywords: Black vulture; Lead; Lead toxicity; Scavenger; Tissue; Turkey vulture