It seems barely a month goes by without someone trying to demonise white-tailed eagles in Scotland.
This time it’s the handiwork of Telegraph ‘journalist’ Auslan Cramb, with an article headlined:
Sea eagles eat more lamb than fish, despite their name, according to research.
We really shouldn’t be surprised that this scaremongering drivel has been churned out by Cramb. He’s the same ‘journalist’ who in October falsely claimed that ‘Wind turbines have killed more birds of prey than persecution this year‘ – a claim we demonstrated was false here.
His latest claim is based on the results of a series of photographs that were taken at a white-tailed eagle’s nest in Argyll between January and July this year. Yes, that’s right, footage from a single nest, filmed during a single period. Hardly representative, is it?
According to SNH, this eagle pair brought in 117 prey items to the nest. 67 of these (57%) were unidentifiable. Of the items that were identifiable, 21 items were mammals, 14 were birds, 7 were fish and ‘8 or 9’ were lambs.
So this camera at this particular eagle’s nest, during this particular period, filmed one or two more lambs than fish. Does that justify the scaremongering headline that sea eagles eat more lamb than fish? Hardly. But then a headline such as ‘Pair of sea eagles enjoy a varied, generalist diet’ isn’t really what the raptor killers want the public to believe, is it?
The article also fails to explain that these ‘8 or 9’ lambs could well have been taken as carrion (i.e. the lambs were already dead and the eagles simply scavenged the carcasses).
To try and pass these results off as a conclusive scientific study is pure desperation. It’s what’s known as ‘utter bollocks’ in scientific terms. Trying to determine raptor diet using a single method (such as nest camera footage) is a well-known problem that is beset with bias. There are numerous methods of obtaining such data (e.g. analysis of regurgitated pellets, analysis of prey remains, camera footage) and considerable research has shown that a combination of methods should be used, rather than a single one. The additional issue of using a sample size of one (nest) is just laughable. It is also well known that the diet of individual eagle pairs can vary across years in western Scotland, as reported by sea eagle experts Mike Madders and Mick Marquiss in 2003.
The most recent, properly conducted, scientific study on white-tailed eagle diet in western Scotland was published in 2013. That study included the analysis of pellet and prey remains from 16 sea eagle nests on Skye, Mull, Lewis and Harris, over an eight year period. The study found that 49.6% of the eagles’ diet comprised seabirds, 19.2% sheep, 13.4% lagomorphs and 6.1% fish. However, the authors acknowledged that the estimation of fish in the eagles’ diet was probably under-estimated due to the methods of dietary analysis that they used.
The purpose of installing the camera at the Argyll eagle pair’s nest was part of an on-going effort to understand the conflict between sea eagles and farming/crofting interests in western Scotland. This is a long-standing and controversial issue that we’ve blogged about a lot (here is an example). It would appear that if farmers/crofters want to deter sea eagles there’s a simple solution – attach a small black plastic box to the lamb’s neck (about the size of a matchbox). Why? Because a load of lambs were radio tagged during an earlier study into alleged lamb-killing eagles and the results showed that not one single lamb was killed by an eagle. The crofters claimed the eagles had been ‘put off’ because of the radio collars/tags. (They also claimed that the eagles had been given supplementary food during the study period, and that some eagles had been ‘bird-napped’ to remove them from the study area!).
UPDATE 22nd December 2014: RSPB Scotland responds to this idiotic Telegraph article here