General licences – Scotland

Common Jay. Photo: Andy Rouse

Everyone is looking at general licences following our successful legal challenge of the system, and in the knowledge that further legal challenges are possible from Wild Justice and from other interest groups. This unprecedented scrutiny is getting statutory agencies and governments to sharpen up their acts.

In Scotland, SNH has commissioned a report from the BTO which is now published – see here.

It’s not a bad report as far as the review of the science is concerned and it does go as far as to exonerate Rook completely from the General Licence 1 (with regard to impacts on nature conservation) as follows:

In relation to General Licence 1, which is issued to reduce impacts on wild bird conservation, there was no evidence that rooks are an important nest predator, or that they are likely to impact otherwise on the conservation of wild birds to support its inclusion on GL1.

For other corvid species the review says:

Magpie: “Analyses of large-scale and extensive national monitoring data provide little evidence for national-scale impacts of magpies on avian prey populations but most studies do not assess the impact of magpies alone”

Carrion/Hooded Crow: “There is evidence that carrion and hooded crows can reduce the local productivity and abundance of prey species where carrion or hooded crow occur at high density, particularly of waders and gamebirds.” However: “Analyses of large-scale and extensive national monitoring data provide little evidence for national-scale impacts of carrion / hooded crows on songbird populations.”

Jackdaw: The worst that is said of this species is that “Jackdaws have the potential to out-compete red squirrels for artificial nest boxes where provided”

Jay: “An opportunistic species, for which the eggs and young of wild birds form part of a mixed diet. Nest predation is perhaps likely to be greatest for open-nesting birds in scrub or woodland habitats”

Given that general licences allow anyone, any time, anywhere to kill unlimited numbers of the listed species (in theory, after the person relying on the licence has tried or evaluated properly non-lethal methods first) these levels of scientific evidence are not remotely adequate to keep Magpie, Jay and Jackdaw on the general licences in Scotland or anywhere else in the UK. It is arguable whether Carrion Crow and Hooded Crow should be listed too, although we in Wild Justice will not be pressing that argument at this time.

Although the BTO reviews of the scientific studies are adequate there is a flaw in the way they summarise the findings of different studies, of different qualities in different parts of the world which is potentially problematic and certainly should be ignored by decision makers who need to look at the detail not just the summary (in Table 6).

The flaw in presentation and summary is as follows, let’s illustrate it with the Rook. The Rook gets top-billing exoneration in this report (perfectly correctly) because there are no studies that are rated (perfectly correctly) by BTO as being in what they call Category 2 (Clear effects in at least some situations) and no studies that are rated (perfectly correctly) as being in what they call Category 1 (Potential effects in at least some situations) and so all of the studies are actually in what they call Category 0 (No demonstrated effect). This works out well for the Rook and results in BTO saying there is no evidence for an impact and therefore no reason for the Rook to be included on General Licence 1 in future (and by extension, to have been included in the past decades). This makes sense. But the Rook was lucky, in our view, because if there had been hundreds of studies showing no impact and a single study (even if conducted in a different continent) suggesting an impact then the BTO would have popped it in Category 2 overall as they only, in the body of the report, report the highest category the studies of a species occupy.

This is the equivalent of convicting someone in the dock if there is one shred of evidence against them but loads of evidence that point to innocence. It’s a poor way to summarise what is, by necessity a complex picture of many studies conducted in different places in different times and to different degrees of rigour, sample size etc.

It is undoubtedly a poor way to summarise the complexity of the range of scientific studies on a subject. An alternative method (which we don’t propose, but we use to illustrate the point) would be to categorise any species that has a single study in Category 0 as a Category 0 species overall because there is evidence for no impact despite their being evidence of impact too – or giving the species the benefit of the doubt. We are not suggesting this as a method, but it is as daft as the one that the BTO actually used because it is essentially a mirror image of that method.

Let’s look at the Jackdaw too. The Jackdaw is popped into Category 1 (Potential effects in at least some situations) because there is at least one study in that category and no studies in Category 2. In fact there are nine studies of Jackdaw which the BTO evaluate as being four in Category 0 and five in Category 1 – an equal split really. It’s not as though all the studies are in Category 1, and Category 1 studies only show a ‘potential impact in at least some circumstance‘. Even if all the studies were allocated to Category 1 Wild Justice would argue that when decision makers come to evaluate them they should drop Jackdaw out of General Licence 1 in Scotland and say that anyone wanting to kill Jackdaws for the purposes of conserving wildlife should apply for a specific licence, giving their evidence of need and with evidence of non-lethal methods that they have tried and which have failed. A pile of Category 1 studies is hardly enough to put a species on a general licence which allows widespread and unlimited killing. But the Jackdaw has an almost equal number of studies in Category 0 as it does in Category 1 and therefore there is not a case to be made for keeping it on General Licence 1. And note, that the only two studies from the UK are both in Category 0 and so there is no UK evidence that lifts the Jackdaw into Category 1 at all. It is pretty clear that the Jackdaw should not be on Scottish General Licence 1 for a moment longer and that it has been traduced for years.

Similar arguments can be made for Jay and Magpie once you look at the individual studies and the numbers in each category and so get behind the BTO’s flawed Table 6 summary of the evidence. It would even be possible to make a decent case for excluding Carrion Crow and Hooded Crow from Scottish General Licence 1 on this assessment. SNH should certainly think hard about whether they really can issue a general licence if the impacts of Carrion Crow and Hooded Crow on wildlife are restricted to impacts on some species (such as Curlew) which live in some places and which would not benefit at all from exercise of the general licence to kill corvids in other places. SNH should look at the approach of NRW in Wales.

The BTO analysis of the individual studies looks OK to us – it is actually quite similar to that which formed the basis for our evidence to Defra months ago – but the report is let down by a flawed method of summarising the complex mix of studies.

When you look at the range of findings of the studies made on various species one finds that there is no justification for continuing to allow widespread unlimited killing of Rook, Jackdaw, Jay or Magpie and that even for Carrion Crow and Hooded Crow there are good reasons for limiting the circumstances and locations under which they can be killed for conservation purposes.