Every time that we mention that we believe that gamekeepers are encouraged to bump off hen harriers on grouse moors there is a predictable outcry from the Countryside Alliance, the Shooting Times, sometimes the National Gamekeepers Organisation and others. They say there is no evidence to back this up and that hardly anyone has been successfully prosecuted for such offences. We'd agree with the fact that there have been few prosecutions dealing with hen harriers (many more for other birds of prey of course) and that is a source of frustration for us.
But one of the advantages of having been around for a while, and paying attention to the science on the matter too, is that one can remember how things used to be.
Here is a quote from the summary of a scientific paper published in 1998:
'In the U.K., a full recovery of Hen Harrier Circus cyaneus breeding numbers is prevented by illegal culling by some gamekeepers who fear the species threatens the future of grouse moors. This study’s main purpose was to estimate how many more Hen Harriers there would be in the U.K. if this culling were to cease.'
Later in the summary, I've missed out some dull bits, the author states:
'If all potential habitats were occupied, present numbers could more than double, to an estimated 1660 nesting females. This estimate represents an average of one nesting female per 25 km2 of habitat, a density which would cause little or no significant economic damage on grouse moors.
'However, because Hen Harriers tend to aggregate, they would not spread out evenly but would nest in relatively high densities on a number of moors. The economic impact on Red Grouse Lagopus lagopus would not be a function of overall numbers, rather it would arise from the uneven dispersion of nesting Hen Harriers.'
And who was this author? None other than Dick Potts, who was then the boss of the Game Conservancy Trust. The paper was published in the journal Ibis Vol 140, pp 76-88.
The RSPB was active doing science on the subject around this time too.
Here is the complete summary of a 1997 paper entitled 'The effects of illegal killing and destruction of nests by humans on the population dynamics of hen harriers Circus cyaneus in Scotland in the Journal of Applied Ecology, Vol 34, pp 1081-1105 :
'1. Breeding productivity, natal dispersal and survival of hen harriers Circus cyaneus were studied between 1988 and 1995 on moorland managed for sport shooting of red grouse, other heather moorland and young conifer forests in the uplands of Scotland. 2. Nest success was much lower on grouse moors than on other land management classes. Annual productivity was 0.8 fledglings per breeding female year on grouse moors compared with 2.4 on other moorland and 1.4 in young conifer forests. Human interference was recorded on half of the grouse moor estates studied and accounted for at least 30% of breeding failures in this land management class. It was much less frequent in the other land management classes. 3. Annual survival of female hen harriers which bred on grouse moors was about half that of females breeding on other moorland. On grouse moors, survival of females which bred unsuccessfully was much lower than that of females which reared at least one fledgling. Survival of breeding females on other moorland was high and unrelated to breeding success. The difference in survival of breeding females between grouse moors and other moors was attributed to killing by humans. On average, 55-74 females were killed each year, 11-15% of the total population of breeding females in Scotland, excluding Orkney. 4. The population of breeding females on grouse moors was estimated to decline rapidly without immigration. Harriers breeding on the other habitats were producing a surplus of female recruits approximately sufficient to compensate for the losses on grouse moors. 5. Most females started to breed at 1 year old and most males at 2 years old. The percentage of breeding males which were 1 year old was higher on grouse moors than on the other land management classes. 6. The median natal dispersal distance of both sexes exceeded 10 km. Harriers fledged from one land management class were often found breeding in another. 7. Natal dispersal resulted in net movements of 1-year-old females between land management classes which were sufficient to reduce the differences in population trend which would otherwise have occurred. Moorland managed for grouse shooting was a sink habitat which received two-thirds of its female recruits from other habitats. 8. The difference in productivity and survival between grouse moors and other habitats was attributed to illegal human interference. It is speculated that, without persecution, the hen harrier population in Scotland would increase, initially by about 13% per year, until a new, but unknown, equilibrium level was reached.'.
There is more science to back up our claims too - but let's just talk about the issue now.
This issue has dragged on for years and no party is blameless. For example, we used to say, and we believed it when we said it, that hen harriers wouldn't do much damage to a grouse shoot. The Langholm study which we helped to fund showed that that was not always the case.
But for those representing shooting interests to claim that there isn't any evidence for killing of hen harriers puts the argument back a few decades.
The thing that has changed since the science was carried out is that there are now even fewer hen harriers on grouse moors - the study in Scotland probably couldn't be done these days there are too few birds - and hen harriers have recovered somewhat in the places where there isn't grouse shooting.
A love of the natural world demonstrates that a person is a cultured inhabitant of planet Earth.
Lazywell - good points. I wasn't at the Partnership Against Wildlife Crime meeting but I am told that the Minister announced two things - the national priorities which still include hen harrier persecution as a national crime priority in England (and incidentally the peregrine was added to this list) and he announced, in these hard times of public spending, a continuation of Defra's funding for the National Wildlife Crime Unit to pursue those priorities. So there isn't anything there that leads anyone to think that illegal killing of raptors is less important to government in these blue (and yellow days) than in the distant red days of this time last year. And although Dick Potts's calculation led on to the 'quota scheme' idea the science of where we are and the politics of where we go next are somewhat different issues. I assume that you and the GWCT still adhere to the view that hen harrier numbers and distributions are limited by men with guns killing them off. It would be very helpful if the GWCT would say so - or say that it has changed its mind on this issue. Which is it?
Landowners need to be more accountable and users of estates - ie the shooters, the fishers and buyers of goods should demand more re assurance that estates are being managed legally and in a way that takes into account the conservation of other species. They may have to pay a little more but then again landowners may make more business and not have to charge more.
How about the shooting fraternity being pro active in this and introducing some sort of certification process - fair trade for eagles and harriers ! - I guess that would be asking a bit much, but then a lot of companies and farm businesses are doing it these days...and in between shooting days they could allow people in to watch nesting harriers and Eagles - people pay good money for that too.
Yes, Mark, Dick Potts’s paper in Ibis was an important contribution to the debate. But remember that it was to be seen in the context of his proposal that there should be some kind of managed solution to the grouse/raptor conflict. That remains the GWCT’s position to this day, and is one shared, I suggest, by the majority of senior raptor ecologists (although some of them probably feel they cannot express it publicly). Dick couched it in terms of a regional quota scheme and concluded that it would actually result in a significant increase in the number of harriers nationally – something which the RSPB has never challenged. Interestingly Dick’s idea has more recently been adopted and developed by Steve Redpath, one of the country’s foremost raptor experts and a scientist who guards his independence jealously.
I note redkite’s suggestion that there should be some kind of working group looking to come up with an overall strategy to resolve this conflict. As I have observed on this site before there already is just such a conflict resolution process underway, facilitated by a charitable body called the Environment Council and including RSPB, shooting organisations, Government agencies and other relevant stakeholders: www.the-environment-council.org.uk/index.php From what I hear, it’s making good progress.
Meanwhile, I recall in one of your posts a week or so ago you referred to a forthcoming meeting of the Partnership for Action against Wildlife Crime at which the relevant minister at Defra, Richard Benyon, would be speaking, and you expressed the hope that he would “agree with us that it's time to take decisive action in the struggle to protect threatened birds of prey”. I can’t help noticing that you haven’t reported on that meeting, but I did see the following report from the Countryside Alliance: “At a recent wildlife seminar, the Environment Minister Richard Benyon responded to a question accusing grouse moor managers of the mass slaughter of hen harriers. First, he pointed to the tiny minority of gamekeepers involved in wildlife crime. The Minister then urged the RSPB and others to stop continually carping and to support the positive environmental benefits that shoot management offers.”
I dare say, as you suggest, that the Countryside Alliance sometimes overdoes the spin a tad. But was it at least accurate in that account? If so, I very much hope you took the Minister’s message to heart, and perhaps in your final months with the RSPB you will strive even harder to support those seeking to resolve this longlasting conflict. What a legacy that would be!
Now this is Science - it says here:
HEN HARRIER POPULATION DYNAMICS & TIPPING POINTS
“Tipping Points in Complex Systems
Despite the diversity of complex systems, from markets to ecosystems to crowd behavior- there are remarkable similarities. For most of the time such systems are stable. However, many complex systems have critical thresholds, called tipping points, when the system shifts abruptly from one state to another. This has been studied in many systems including market crashes, abrupt climate change, fisheries collapse, and asthma attacks. Despite the complexity and number of parameters within such systems, the meta-state of the system may often be dependent on just one or two key state variables
Recent research has indicated that as systems approach a tipping point they begin to share common behavioral features, irrespective of the particular type of system52. This unity between the dynamics of disparate systems gives us a formalism through which to describe the dynamical state of globalised civilisation, via its proxy measure of GWP, and its major state variable, energy flow.
We are particularly interested in the class of transitions called catastrophic bifurcations where once the tipping point has been passed, a series of positive feedbacks drive the system to a contrasting state. Such ideas have become popularised in discussions of climate change. For example, as the climate warms it drives up emissions of methane from the artic tundra, which drives further climate change, which leads to further exponential growth in emissions. This could trigger other tipping points such as a die-off in the amazon, itself driving further emissions. Such positive feedbacks could mean that whatever humanity does would no longer matter as its impact would be swamped by the acceleration of much larger scale processes.
For want of a nail the shoe was lost.
For want of a shoe the horse was lost.
For want of a horse the rider was lost.
For want of a rider the battle was lost.
For want of a battle the kingdom was lost.
And all for the want of a horseshoe nail.
Interesting comments, Mike !
Bearing in mind the current high profile of forestry, its also interesting that Hen Harrier which I think its true were extinct on the British mainland ? broke out from Orkney into Scotland as a result of keepers going to the 1st world war - and, tragically, all too few returning. But it was probably the new forests that allowed it to spread all the way to Wales - a combination of high vole numbers on newly planted forests but equally important the fact that foresters didn't (and still don't persecute) raptors. Sadly, Hen Harriers aren't a species that return to replanted clearfells and what happened when this habitat declined is very well known.
Its the same for other species - especially Goshawk which after decades of persecution in the founder population in the Peak District (which goes on to the present day) took off as the huge new forests matured - but they haven't spread into more populated lowland which, I seem to remember, from Prof Ian Newton's (ex RSPB Chairman) work is richer in prey & could/should hold even better numbers.