title: Widespread exposure to lead affects the body condition of free-living whooper swans Cygnus cygnus wintering in Britain.
abstract: Lead poisoning, through the ingestion of spent lead gunshot, is an established cause of morbidity and mortality in waterbirds globally, but the thresholds at which blood levels begin to affect the physiology of birds in the wild are less well known. Here we determine the prevalence of lead exposure in whooper swans and, for the first time, identify the level of blood lead associated with initial reductions in body condition. Blood lead elevated above background levels (i.e. >20 μg dL(-1)) was found in 41.7% (125/300) of swans tested. Blood lead was significantly negatively associated with winter body condition when levels were ≥44 μg dL(-1) (27/260 = 10%). Our findings indicating that sub-lethal impacts of lead on body condition occur at the lower end of previously established clinical thresholds and that a relatively high proportion of individuals in this population may be affected, reaffirm the importance of reducing contamination of the environment with lead shot.
authors.affiliation: Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, UK; Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, TR10 9EZ, UK. Electronic address: Julia.Newth@wwt.org.uk.
authors.forename: J L
authors.initials: JL
authors.lastname: Newth
authors.affiliation: Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, UK.
authors.forename: E C
authors.initials: EC
authors.lastname: Rees
authors.affiliation: Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, UK.
authors.forename: R L
authors.initials: RL
authors.lastname: Cromie
authors.affiliation: Environment and Sustainability Institute, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, TR10 9EZ, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: McDonald
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, TR10 9EZ, UK.
authors.forename: S
authors.initials: S
authors.lastname: Bearhop
authors.affiliation: Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Pain
authors.affiliation: Institute of Biological Environmental Sciences, University of Aberdeen, AB24 2TZ, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Norton
authors.affiliation: Institute of Biological Environmental Sciences, University of Aberdeen, AB24 2TZ, UK.
authors.forename: C
authors.initials: C
authors.lastname: Deacon
authors.affiliation: Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, UK.
authors.forename: G M
authors.initials: GM
authors.lastname: Hilton
mesh_terms: D000818:Animals; D046090:Anseriformes / Q000097:blood / Q000254:growth & development*; D001715:Bird Diseases / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D004781:Environmental Exposure; D005260:Female; D007854:Lead / Q000097:blood / Q000633:toxicity*; D007855:Lead Poisoning / Q000097:blood / Q000662:veterinary*; D008297:Male; D012621:Seasons; D006113:United Kingdom
chemical_list: D007854:Lead
keywords: Body condition; Impacts; Lead gunshot; Lead poisoning; Swans