I’m grateful to various clever people for contacting me about yesterday’s blog about the extreme unlikelihood of so many male Hen Harriers disappearing from active nests with RSPB involvement. My brain was aching a bit so I am grateful for others’ input.
The probability of 5 or more male Hen Harriers disappearing through ‘normal’ levels of mortality over a breeding period from 9 nests is 0.0033% (and the probability of 5 exactly disappearing is 0.0032%).
Here are the probabilities of other numbers of disappearances:
1 or more is 37% (so still more likely to lose none)
2 or more is 7.1%
3 or more is 0.84%
4 or more is .064%
5 or more is .0033%
As far as I know, but I don’t know much, the males survived at the three other nests in England this year.
So there must be something pretty odd happening.
I think some people may have missed the point of yesterday’s blog – yes, we all know that Hen Harriers are persecuted in various ways (Inglorious Chapters 1 and 6 are good places to read about this type of thing) but my suggestion is that nests with some sort of RSPB involvment were targetted specifically this year to make the RSPB look ‘bad’. If this happened, then whoever was doing it went a bit over the top didn’t they?
The press headlines from the grouse shooting side are all about how many chicks were produced and how many nests failed. They indeed don’t look great for RSPB because quite a few chicks fledged from non-RSPB-involvement nests. This makes a good headline for the grouse shooting side of the argument, but things look very different when looked at in the way of yesterday’s and this blog post.
Of the 9 Hen Harrier nests with RSPB involvement 3 succeeded (2 on FC land and 1 in Bowland) and 6 failed. Of the 6 that failed, including the one at the RSPB nature reserve at Geltsdale, 5 lost their males. The chance of 5 nests losing their males over this period is around 0.0033% ie it is vanishingly minute.
So, something very odd is going on. It’s either that the RSPB are really really rubbish at guarding nests and cause male (but not female abandonment of nests) or that some other factor is involved. My money would be on the other factor. My money is that it would be wildlife crime, and perhaps coordinated and targetted wildlife crime.
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This sounds like an item on Radio 4’s More or Less. Maybe its worth highlighting this particular blog to the programme?
Also worth asking the MA and BASC and HOT if they disagree with your maths or conclusions. And if they disagree, given the maths, what are their grounds for doing so.
Oh, and of course the Telegraph might want to comment too…
Apparently even Lin Murray, spin doctor for Hawk and Owl Trust, who seems to be off her rocker with other ideas also believes that the ‘missing’ male Hen Harriers from the Forest of Bowland this year were “deliberately targeted by somebody who wanted to prove a point.”..“At least some of them were, in my opinion [killed in a revenge attack against RPSB]. And if you think that’s bad, if [driven] grouse shooting was banned, we would see a lot worse.” Notice the threat which HOT seems to be using!
https://olliesbirdingblog.wordpress.com/2015/08/22/doing-a-deal-with-the-devil-hawk-owl-trust-return-to-the-hen-harrier-fray/
Spin doctoring has become so prevalent that she is claiming that UK Hen Harriers are somehow genetically inferior because they keep attempting to breed on areas where there is the best cover and the highest density of prey i.e. grouse moors. This spin (scientific fallacy) gives the HOT the excuse to introduce lowland continental birds in the hope that the HHs will not notice the abundance of prey and nesting cover on grouse moors and somehow choose to breed in similar habitats in the lowlands. Reminds me of the White-tailed Eagles on Mull. The story goes amongst the farmers that they found the first nest in a conifer and told the experts. They were apparently told that they must be mistaken, as White-tailed Eagles only breed on cliffs. This is the standard joke of experts v farmers on Mull and it is quite a good one. White-tailed Eagles in Scotland breed primarily in conifers (and as far as I am aware rarely on cliffs).
There is a chance that Hen Harriers taken from lowland continental birds might choose to breed in the lowlands but i doubt it. As in the case of the sea-eagles, birds breed where the conditions are optimum not where HOT and the game lobby wants them to. Even if it does work for some birds there are so many other problems. 1. What happens when they stray onto grouse moors. Same as always they are shot. 2. What happens when they breed in fields and are a problem for farmers, I can’t imagine they will be happy. 3. There just isn’t that much suitable lowland habitat. There is on Dartmoor, Exmoor, Salisbury Plain but they just aren’t going to stay put and are bound to expand onto grouse moors. (The Tories and Labour have both promised to build 1 million new homes). 4. Why go to all this trouble to support the wishes of criminals when the moorland population will expand rapidly, as proven on Langholm, when the killing stops.
Sign the ban.
https://petition.parliament.uk/petitions/104441
So, leaving aside the Geltsdale nest, and assuming the “other factor” in Bowland is a human one and not disease (females not affected though) and other animal predators (again females, more vulnerable, but not affected) then what would be the profile of the human perpetrators?
a) Someone – let’s face it, probably male – who lives in the vicinity of Bowland. I can’t imagine that people would come from a great distance to commit wildlife crime. Also they would need at least some local knowledge of the terrain, access points and the range of the male birds. They would also need some knowledge to identify the hen harriers.
b) Someone who has access to poisons, shotguns or suitable traps? I don’t know if traps would catch male hen harriers anyway – as they are not scavengers, are they? How many of the general public own or can access shotguns – I would think a small number of total population? Poison would be easier (e.g. rat poisons) – but again, would a hen harrier be interested in poisoned bait? So would I be correct in thinking that shooting is by far the most likely option?
c) Taking into account that “Sky” & “Hope” disappeared on grouse moors adjacent to UU land last year and their tags/corpses have never been found, then is it likely that the males belonging to the UU nests met the same fate as the corpses have not been found? If this is a believable scenario, then the perpetrator must be someone who could gain access to these grouse moors with a shotgun without being seen or who had a right to be there. If it was someone who could trespass carrying a large gun without being seen by the locals/ estate employees/ RSPB watchers this would mean even more local knowledge.
So, can I assume it was a local male, who owns a shotgun, fit enough to walk quite long distances over rough terrain (which also narrows the field), who is unlikely to get stopped for trespass, and with a motive to kill hen harriers?
There cannot be all that many men in Bowland (an area of low population) who fit the bill, can there? True, there will be farmers, field sportsmen and gamekeepers and maybe a few others (poachers?). But, I would imagine farmers would be too busy to march over the moors with a shotgun in the hope of being able to pot one hen harrier, let alone four – and why would they want to anyway – not that many Bowland farmers have free-range hens?
Don’t think poachers would bother as I don’t think hen harriers would make it to restaurant menus. So which groups does that leave? Or is it a ‘lone wolf’ maniac?
The above are just my rambling thoughts – anyone got any better ones? Incidentally, regarding satellite tags, can anyone other than the RSPB access the information being sent out by these tags? And if so what equipment would they need?
NorthernDiver – thank you. Well, they might have flown away – bvut I doubt it.
Trapping and poisons are perfectly possible methods, but I would guess that shooting is the most likely of all. But we just don’t know.
Since the birds weren’t tagged (as far as I know) the lack of a body being found doesn’t tell us much – no-one knows where to look.
“So, can I assume it was a local male, who owns a shotgun, fit enough to walk quite long distances over rough terrain (which also narrows the field), who is unlikely to get stopped for trespass, and with a motive to kill hen harriers?”
I wouldn’t go with shotgun, too much noise. think along the lines of a poacher, high powered multi shot air rifle used in conjunction with thermal imaging and probably the same b*****d who has been killing birds at known roosts. Also local isn’t a cert, some people who beat or pick up on a shoot travel some distance to work there and will do almost anything to help out on the shoot to keep in favour.
I hope next year the RSPB upgrades its technology around the nest sites to take account of this and hopefully protect the full range of the hunting male or catch these sad individuals in the act
The fact that supplementary feeding works demonstrates that it would be perfectly possible to administer poison to a male hen harrier but the likelihood would be that it would carry the poisoned bait back to the nest to give to the female who would then die on or near the nest, leaving a conveniently recovered carcass to be analysed and shown to be poisoned. Assuming the perpetrator is not stupid it seems that shooting is the likeliest method.
The individual wouldn’t have to be particularly fit. Most gamekeepers seem to drive around on quads these day. Add that to the list that likely suspect would have.
Mark,
Have the RSPB, as far as you know undertaken some geographical profiling (see https://en.wikipedia.org/wiki/Geographic_profiling), working with the police and other professionals (e.g. psychologists)?
In a murder (human) inquiry, where there are multiple victims, the police map the locations of victims and perhaps other evidence such as weapon(s), which, when human behaviours are included and other data no doubt, can then provide a lot of information on the likelihood of where the perpetrator(s) may reside/ work. Patterns emerge which can be spatially presented (temporally as well as geographically).
Given that humans are ‘murdering’ their victims, in this case, hen harrier(s), then I see no reason why this tool cannot be brought in to play in this instance. I am sure a psychologist can produce a profile(s) of the perpetrator(s), which may be able to narrow down potential locations of suspect(s).
I am also fairly confident in my understanding that those who commit wildlife crime, are also more likely to be aggressive towards humans (wives, children, etc); so there is also a human interest in eradicating wildlife crime beyond the immediately obvious need to restore the uplands (for example) to what they should be like.
It would be an interesting study; and more than an academic one. And the finances to undertake the work may be worth committing to in the same way as tagging hen harriers.
Well let’s tell the ‘shooting community’ that for every hen harrier which disappears a hundred or a thousand people will trespass on the surrounding grouse moors that year, after 12th August. That’ll discourage them!
I was always pretty dim at statistics but in order to show a conspiracy, surely you take a different approach. So of course the disappearance of males is not a fluke, it as good as conclusive evidence of illegal killing. But to show a conspiracy to damage the RSPB you would have to do something like estimate the rate of successful illegal killing of male birds and then, given that, estimate the probability of the particular killing distribution across the known nests.
My guess is that the resultant probability would be quite low. Which, if so, would support my prejudice that the killers are bastards but not clever bastards.
I agree with the train of thought in these comments, which I think ( from what little I know ) would be supported further by the successful nests being in relatively remote and unfamiliar territory for the profile of person(s) who might commit the crimes or be able to wander at will with a shotgun thereabouts.
Technology is improving all the time. Would it be possible to attach a tiny camera to a hen harrier with a live stream back to a control? Just a thought.