This is an interesting paper. Here is the Abstract;
Ingestion of lead (Pb) derived from ammunition used in the hunting of game animals is recognised to be a significant potential source of Pb exposure of wild birds, including birds of prey. However, there are only limited data for birds of prey in Europe regarding tissue concentrations and origins of Pb. Eurasian buzzards (Buteo buteo) found dead in the United Kingdom during an 11-year period were collected and the concentrations of Pb in the liver and femur were measured. Concentrations in the liver consistent with acute exposure to Pb were found in 2.7% of birds and concentration in the femur consistent with exposure to lethal levels were found in 4.0% of individuals. Pb concentration in the femur showed no evidence of consistent variation among or within years, but was greater for old than for young birds. The Pb concentration in the liver showed no effect of the birds’ age, but varied markedly among years and showed a consistent tendency to increase substantially within years throughout the UK hunting season for gamebirds. The resemblance of the stable isotope composition of Pb from buzzard livers to that of Pb from the types of shotgun ammunition most widely-used in the UK increased markedly with increasing Pb concentration in the liver. Stable isotope results were consistent with 57% of the mass of Pb in livers of all of the buzzards sampled being derived from shotgun pellets, with this proportion being 89% for the birds with concentrations indicating acute exposure to Pb. Hence, most of the Pb acquired by Eurasian buzzards which have liver concentrations likely to be associated with lethal and sublethal effects is probably obtained when they prey upon or scavenge gamebirds and mammals shot using Pb shotgun pellets. https://www.sciencedirect.com/science/article/abs/pii/S026974912036317X
So, yet more evidence (though none is needed) of environmental harm caused by lead ammunition and a study that removes the ‘they could have got the lead from anywhere’ defence.
Lead levels in UK Buzzards were higher than those in France, Germany, Denmark, Poland, Portugal and Spain, but lower than those from Italy.
Lead concentrations in UK Buzzards increased consistently, and several-fold, during the shooting season, when vulnerably wounded or dead gamebirds would be more easily found by scavenging and hunting Buzzards.
Most of the lead in UK Buzzards that have lethal doses or sublethal effects probably comes from lead ammunition. Part of the significance of this is that the release of large numbers of non-native captive-bred gamebirds in or near sites of high nature conservation importance which have been designated, even partly, for their raptor populations will be harmful to those species. This forms part of the Wild Justice case against unlimited release of such gamebirds. Unfortunately it was not part of the biological evidence assessed in the recent DEFRA/NE/BASC/GWCT/University of Exeter review of such impacts. It remains a problem which DEFRA needs to tackle. The judicial review of theWild Justice challenge on gamebird releases will be heard on 3 and 4 November.