The Predatory Bird Monitoring Scheme: Identifying Chemical Risks to Top Predators in Britain

Abstract

The Predatory Bird Monitoring Scheme (PBMS) is a long term (>40 y), UK-wide, exposure monitoring scheme that determines the concentration of selected pesticides and pollutants in the livers and eggs of predatory birds. This paper describes how the PBMS works, and in particular highlights some of the key scientific and policy drivers for monitoring contaminants in predatory birds and describes the specific aims, scope, and methods of the PBMS. We also present previously unpublished data that illustrates how the PBMS has been used to demonstrate the success of mitigation measures in reversing chemical-mediated impacts; identify and evaluate chemical threats to species of high conservation value; and finally to inform and refine monitoring methodologies. In addition, we discuss how such schemes can also address wider conservation needs.

Second generation anticoagulant rodenticides in predatory birds: Probabilistic characterisation of toxic liver concentrations and implications for predatory bird populations in Canada

“…In the French Department of Loire Atlantique, 73% of a sample consisting of 321 common kestrels (Falco tinnunculus), common buzzards (Buteo buteo), barn owls and 16 322 tawny owls (Strix aluco) had detectable SGAR liver residues (Lambert et al 2007). In the 323 UK, between 40% and 74% of barn owls, kestrels, and avian scavengers such as buzzards 324 and red kites (Milvus milvus) found dead from various causes had detectable liver SGAR 325 residues Shore et al, , 2006Walker 2008b). However, it 326 should be noted that the sampled areas of Canada were those with higher population 327 densities and where landscape features are not greatly dissimilar from Europe.…”

Superpredation increases mercury levels in a generalist top predator, the eagle owl

“…The potential consequences for these species, many of which have unfavourable conservation status or are keystone predators, raises the need for long-term national monitoring programs to assess the levels of contamination in top predators (Gjershaug et al 2008;Walker et al 2008), including temporal and spatial trends, and their relationships to demographic parameters (breeding success, survival) and diet composition.…”

Feather corticosterone content in predatory birds in relation to body condition and hepatic metal concentration

“…Birds were randomly selected from the PBMS archive which contains selected tissues from the carcasses of predatory birds that have died from a variety of causes (Newton et al, 1999;Walker et al, 2008). Whole wings from a total of 83 individuals were stored at -20°C until analysed.…”

“…Various monitoring schemes across Western Europe measure contaminant concentrations in raptors and owls, using these apex predators as sentinels of environmental pollution or to directly assess the risk to individual species that are of conservation concern (Gomez-Ramirez et al, 2014). In the United Kingdom this work is conducted by the Predatory Bird Monitoring Scheme (PBMS; Walker et al, 2008). Most schemes, including the PBMS, measure exposure of birds to particular contaminants but lack information on collateral effects.…”