AT last the systematic “disappearance” of raptors from locations adjacent to driven grouse moors is being brought into the public domain. The reactions to this from the field sports lobby indicate, however, a woeful inability to comprehend certain basic principles and a profound confusion between the legal and scientific senses of evidence.

When it is said that there is a low probability that an event takes place according to chance, this means that it is not something that normally takes place. It follows that there is a high probability that it happens because of some deliberate intervention, as a consequence of extraordinary circumstances.

If the tags on two raptors stop working within hours of each other, at ground level, at the same location, in an area where other tags on raptors have in the past suddenly stopped working, then common sense as well as rigorous probability theory can reasonably conclude that the probability of this happening randomly, by chance, under the normal course of events, is so low that this is not even worth thinking about. Which means that there must have been some deliberate intervention or departure from the normal course of events that caused them to stop working.

Defenders of field sports are keen to emphasise that there are many possible explanations for the disappearance of raptors’ tags and believe, apparently quite genuinely, that each of these has an equal chance of taking place. They insist that until evidence is brought forward to support any one of these, we simply do not know and should not engage in idle speculation.

The transponders might simply have fallen off the birds and shattered into untraceable pieces when they hit the ground; maybe they just stopped working and the birds are still flying free; maybe the RSPB or some other anti-establishment organisation faked it all in an effort to discredit a respectable and vital element of the Scottish economy; the birds and their transponders might have spontaneously combusted; aliens could have appeared to pluck the birds away for experimentation in the mother ship. Who knows? When you maintain a wilful ignorance of simple probability, anything can happen. The only explanation for the disappearance of the birds that the field sports lobby does not countenance is that somebody was paid discretely to murder them.

Most bizarre was reference to the case of an eagle called Fred, whose transponder suddenly stopped working at ground level in the Pentland Hills. There was no trace at the location, but strangely it gave out a brief signal some time later in the middle of the Forth. Here was proof that these transponders are unreliable and demonstration that no evidence gathered from any transponder should ever be taken as evidence of anything, ever. Certainly no proof that something untoward happened to Fred, who is undoubtedly still flying free. Maybe he landed briefly in the Pentlands and in the process of preening, switched off his transponder and loosened the harness sufficiently for the whole lot to fall off as later he flew past the Isle of May on his way up north. Or maybe he was shot by persons unknown, his body and transponder driven to an East Lothian harbour and taken out to sea to be dumped.

There is no evidence available to say which of these explanations is correct, but on the balance of probability, one is rather more plausible than the other. Likewise, with more and more raptors mysteriously disappearing at a number of specific locations adjacent to driven grouse moors, there is now a well-established scientific connection between the existence of these grouse moors and the disappearance of raptors.

Although there is nothing here that can be taken to a court of law, it is enough evidence to form the basis of policy. It may be next to impossible to gather evidence sufficient to prove that a particular person has killed a particular bird of prey, it is, however, perfectly possible to introduce sensible licensing of driven grouse moors and sporting estates that ensures licences will simply not be issued in areas where tagged raptors regularly “disappear”.
Andy Duncan
Cupar