Submitted by PBMS Admin on
The current report is the seventh in a series of annual reports that describe the monitoring of Second-Generation Anticoagulant Rodenticide (SGAR) liver residues in barn owls (Tyto alba) in Britain. This work is one element of an overarching monitoring programme undertaken to track the outcomes of stewardship activities associated with the use of anticoagulant rodenticides. The barn owl (a generalist predator of small mammals) as a sentinel species is used for exposure monitoring. The measurement of liver SGAR residues in 100 barn owls found dead in 2021 across Britain is compared with the residues from 395 barn owls found dead between 2006 and 2012 (referred to as 'baseline years'), prior to changes in anticoagulant rodenticide authorisations and the onset of stewardship.
Overall, there were significant differences in liver SGAR accumulation between the barn owls in the baseline years and 2021: a potential reduction of bromadiolone and difenacoum and an increase of brodifacoum residues from 2016. However, the lack of significant reductions in the sum of SGAR residues in barn owls in 2021 suggests that full implementation of stewardship since 2018 has yet to result in a statistically significant reduction in the exposure of barn owls to SGARs.
For the full report (and all of our previous reports), see our Reports page.