On Friday the following comment was submitted to my post on Access Rights and Grouse Moors (see here)

“Without mammalian (mustelid and rodent) control there would be no ground nesting birds of any kind, grouse or otherwise.”

Comment: This is plainly wrong. Ground nesting birds evolved along with mustelids and rodents long before any predator control by humans took place.  Ground nesting birds also breed successfully on conservation estates where no predator control takes olace.

The person continued:

“Single issue fanatacism and the politics of envy don’t make for good conservation. See Professor Vidal Marcström’s work on the matter, Universoty of Uppsala, Sweden, from the 1970’s – it saves trying to reinvent a broken wheel, had the RSPB followed his research find8ngs, we’d still have a viable woodland grouse (caper and blackgame) population in the areas where they “manage” in Badenoch. We all want the same thing, but the prescription you advocate clearly doesn’t work on the ground. Half full glass should be filled, not emptied.”

Comment

One of the favourite tactics of the defenders of intensive grouse moor management, climate change deniers etc is to make references to research which, they claim, supports their case.  It can take considerable time and effort to check this and counter those arguments. Luckily, in respect of the comment above, I have a copy of Adam Watson and Robert Moss’s book Grouse published in 2008.

Watson and Moss cite three pieces of research from Prof Marcstrom, all dating from the 1980s, the last of which was titled “The impact of predation on boreal tetraonids during vole cycles: an experimental study:

“Many have concluded that foxes and martens cause the poorer breeding success of woodland grouse in south Fennoscandia. Supporting this view, experimental killing of foxes and martens on a Swedish island increased the breeding success of grouse” (Marcstrom et al 1988).

Watson and Moss then give the following commentary:

“The island experiment, however, did not distinguish the separate impacts of foxes and marten. Nor did it explain the role of stoats, which are more abundant in North Finland, where grouse breed better. Perhaps conditions in north Finland favour both grouse and stoats.”

“We use data from the Finnish study to check whether year-to-year variations in grouse breeding success were related to the abundance of pine martens. In the south of Finland there was no significant association. In the north the raw data (fig 165) also suggested no association, but after one allows for annual variations in vole and pine marten abundance, breeding success was better in years with few foxes. It was also better in years with more voles, which fits the idea that predators kill fewer grouse when there are more voles to eat. However, after allowing for annual variations in vole and fox abundance, it appeared that grouse breeding was better in years with more pine martens, the opposite of what one would expect”.

Watson and Moss then observe that the relationship between the number of predators and the breeding success of grouse is further complicated by other factors, such as “the availability of good ground cover”.

The crucial point here is that whatever else Prof Marcstrom’s work shows, it clearly doesn’t demonstrate that “without mammalian control there would be no ground nesting birds of any kind”.  The claim in the comment  on my post that “had the RSPB followed his research find8ngs, we’d still have a viable woodland grouse (caper and blackgame) population in the areas where they “manage” in Badenoch” is complete and utter rubbish.

 

Comments on Parkswatch posts

In the past I have taken a fairly liberal approach to comments on Parkswatch and allowed people to express what they think or feel.  While I still very much believe in the value of dialogue and debate – and have learned lots from critical comments people have made on my posts – there are a few people who have tried to use Parkswatch to misinformation.

There is far too much of misinformation on both mainstream and social media  without parkswatch adding to and I have now decided there is only so much that readers should be expected to tolerate or I should have to spend countering ridiculous claims.. Hence why I have not published the comment I quoted above in its own right.

It is worth adding that the people circulating such misinformation never give their real names and sometimes hide behind anonymised emails.  While there are very good reasons why some people cannot reveal their identity when commenting (eg because there could be consequences for their employment), it is preferable that commentators are open about who they are where possible.