THE RSPB has been criticised for spending £300,000 to exterminate a rare species of rat on a tiny Scottish island.
The black rats of The Shiant Isles have lived there for centuries and are thought to be the UK’s only self-sustaining population of the creatures.
But the RSPB is spending £90 per rat – most of it from public funds – to cull the animals.
The charity claim the black rats eat seabird eggs and chicks on the islands, a few miles southeast of Lewis in the Outer Hebrides.
This claim is contradicted by a study which could not prove one way or the other if the rats ate live birds.
Despite that, the cull started this winter, with 50% of the £311,000 cost paid by the EU and a “significant” part of the rest funded by government quango Scottish Natural Heritage (SNH).
All 3,500 black rats on the islands – which are privately owned and home to just seven people – will be killed, giving a cost per dead rat of £88.86.
Eben Wilson – director of Taxpayer Scotland – said: “This does look rather like mission impossible, with costs to match in inhospitable terrain and weather conditions.
“Given the per rat costs of extermination, you have to question the value obtained from the taxes required. There really has to be a reconsideration as to whether this is a good use of our money.”
He added: “A local volunteer programme might well achieve a near similar result at vastly reduced cost. Do the ends really justify the publically funded means which always seek perfect outcomes at great cost?”
A 2002 study published by the British Ecological Society concluded that rats on the island had been eating seabirds – but could not tell whether they had been hunting live ones or simply scavenging on the bodies of already dead birds.
And others have claimed that – as the only self-sustaining black rat population in the UK – the species should be considered for protection rather than being thought of as an “invasive” threat.
David Wembridge, the surveys officer at the People’s Trust for Endangered Species noted: “Black rats are a naturalised species in the UK, having lived here for two millennia.
“The UK is home to fewer mammal species than continental Europe and eradicating the Shiant Isle black rat population would further decrease this number. The conservation of the black rat on the Shiant Isles, therefore, alongside the conservation of seabirds, needs to be carefully considered.”
He also claimed that the population on the islands is as low as 1,000 – 75% of the total population of the animals in the UK.
If this is the case the cost-per-rat for extermination would be an eye-watering £311 per rat.
The RSPB said the rest of the cull cost was from donations.
A spokesman said: “Invasive non-native species are one of the greatest threats to global biodiversity, and Scotland’s globally important seabird colonies are also at threat from this.
“Eradication of non native species is an expensive business.
“The work on the Shiants is being delivered in a cost-effective manner and is good value.
“By the same token as one suggesting it is costing £90 per rat, one could just as easily suggest that it is costing £5 per puffin.
“Black rats remain common and widespread throughout their historic natural range in Asia, where the population is stable and faces no known threat to its conservation status. The species is also still common in large areas of the world where it has been introduced.”