Risk assessment of birds foraging terrestrially at Marion and Gough Islands to primary and secondary poisoning by rodenticides

A risk assessment of terrestrial-foraging birds to rodenticide poisoning at Marion and Gough Islands reveals that while some species, such as lesser sheathbills and Gough moorhens, show potential susceptibility to both primary and secondary poisoning, others like sub-Antarctic skuas are less likely to be affected during winter baiting operations. The study found that captive birds exhibited minimal consumption of non-toxic bait pellets, but field observations showed that Gough moorhens did consume them. Sheathbills and moorhens also consumed mouse carcasses, whereas Gough buntings showed little interest in such prey. The research suggests that precautionary measures, including temporary captivity of vulnerable species during poisoning exercises, are necessary to mitigate risks, despite the limitations posed by cage effects on behavioral observations.

Wanless, R. M., Cooper, J., Slabber, M. J., & Ryan, P. G. (2010). Risk assessment of birds foraging terrestrially at Marion and Gough Islands to primary and secondary poisoning by rodenticides. Wildlife Research, 37(6), 524–530. https://doi.org/10.1071/wr10005