SNH Commissioned Report 871: Stoat (Mustela erminea) on the Orkney Islands - assessing the risks to native species
Stoats (Mustela erminea) were first recorded on Orkney in 2010 following an assumed accidental introduction. Stoats are native to mainland Britain where they prey on a variety of mammals, birds and their eggs. The Orkney vole (Microtus arvalis orcadensis) is an important prey species for several nationally important populations of raptors on Orkney including hen harriers (Circus cyaneus) and short-eared owls (Asio flammeus). It is feared that the introduction of stoats may lead to a depletion of Orkney voles which in turn could affect the predators that depend on them. Three plausible scenarios regarding the potential outcome for the impact of stoats on Orkney ecology are presented. We consider the most likely outcome of a long-term impact of stoats on Orkney to be that Orkney vole populations will become permanently reduced to lower average densities. The likelihood of this scenario having a major detrimental effect on harriers, short-eared owls through depletion of a key prey species, and also predation on ground nesting birds to be high.
Format : 36 pages; 2MB
Published in 2015