No breeding hen harriers on Angus Glens grouse moors since 2006

hh LAURIE CAMPBELLWe were just doing a bit of background research on claims made by the grouse-shooting industry’s propaganda campaign website, The Gift of Grouse (more on that shortly) and we thought we’d share some startling figures.

The following data are from the Scottish Raptor Monitoring Scheme (SRMS) annual reports. The SRMS was established in the summer of 2002 (website here) and is currently a consortium of eight organisations who pool their data to provide information on raptor trends across Scotland (distribution, abundance, breeding success etc).

Here are their results on hen harrier monitoring in Angus from 2003-2014 (2015 data not yet available).

2014: 26 x HH home ranges checked; 0 occupied by breeding pairs.

2013: 23 x HH home ranges checked; 0 occupied by breeding pairs.

2012: 30 x HH home ranges checked; 0 occupied by breeding pairs.

2011: 31 x HH home ranges checked; 0 occupied by breeding pairs.

2010: 23 x HH home ranges checked; 0 occupied by breeding pairs.

2009: 1 x HH home range checked; 0 occupied by breeding pairs.

2008: 27 x HH home ranges checked; 2 occupied by breeding pairs; 0 fledglings.

2007: 15 x HH home ranges checked; 0 occupied by breeding pairs.

2006: 5 x HH home ranges checked; 5 occupied by breeding pairs; 1 pair fledged 3 young.

2005: 4 x HH home ranges checked: 4 occupied by breeding pairs; 2 pairs fledged total of 7 young.

2004: 5 x HH home ranges checked; 4 occupied by breeding pairs; 1 pair fledged 5 young.

2003: 5 x HH home ranges checked; 5 occupied by breeding pairs; 2 pairs fledged total of 7 young.

Pre-2003 data are unavailable (as the scheme only started in late 2002) but a comment next to the 2003 data is quite telling: “Noteworthy are the two pairs that successfully reared young on the grouse moors of Angus, the first for many years“.

So, despite comprehensive monitoring efforts since 2007 (with the exception of 2009 when only one known home range was checked), hen harriers have failed to breed successfully on the grouse moors of the Angus Glens since 2006.

Why is that?

And why hasn’t the Gift of Grouse campaign mentioned this on their website, on their social media accounts, in their press releases, or during the parliamentary receptions they’ve been enjoying at Holyrood where they’ve been feted as environmental champions by some pretty naive MSPs?

36 thoughts on “No breeding hen harriers on Angus Glens grouse moors since 2006”

  1. Having lived in the Angus Glens for quite a few years and taken an interest in things I do not find the figures at all surprising. It would also be interesting to know how many times the fire brigade has been called out to the Angus grouse moors as their heather burning practises were very poor too … so poor, in fact, that it came to the stage where Tayside Fire Brigade had to visit and give them a warning. I frequently used to see keepers light a fire and then drive on and light another one without the first being extinguished AD Infinitum.

    1. “Heather is burned, with government grants, to ‘improve” grouse moors, reducing their ability to retain water. Land left bare between crops also causes rain to run off, eroding the soil; hence the chocolate colour of a flooding river”
      An extract from a recent scientific survey into the causes of recent flooding in Yorkshire.

  2. Nobody can dispute the fact that we have a major stalemate in this long standing grouse/harrier conflict. I’ve personally spent months of my life walking the Angus Glens monitoring this superb raptor and would like to see the data presented accurately.

    However in your above article could I please point out that data is available pre 2003 and that the comment next to the 2003 data is quite telling: “Noteworthy are the two pairs that successfully reared young on the grouse moors of Angus, the first for many years“ is totally untrue.

    Data is available between 1998 and 2002, 11 pairs of hen harriers in Angus fledged 28+ young.

    Also your figures for checking home ranges are totally misleading e.g. why would only 1 home range be checked in 2009 and in the years 2003-2006 the numbers are grossly underestimated. ?Why.

    1. Mike,

      Thanks for the pre-2003 data. Where are these from and who collected them? Clearly not SRMS data (as our blog says, SRMS didn’t get going until summer 2002). Interesting that, according to the data you’ve provided, there were 11 breeding pairs during the period 1998-2002 and now there are no breeding pairs. Any idea why that might be? Perhaps you could ask your gamekeeper pals?

      The figures you challenge are not “our” figures – they are presented in this blog exactly as they’re presented in the SRSM annual reports. If you want to dispute the accuracy of the data you’ll need to do that with the Scottish Raptor Monitoring Group, not us.

      Do you agree that there hasn’t been a successful breeding pair of hen harriers on the grouse moors of the Angus Glens since 2006?

        1. Mike, do you ask for the real names of those who own the grouse moors on which the hen harrier persecution takes place as they are extremely difficult, often impossible, to identify by conventional means or do/would you co-operate simply with their gamekeepers?

        2. I would like to hear a reply to the question “Do you agree that there hasn’t been a successful breeding pair of hen harriers on the grouse moors of the Angus Glens since 2006?” and if you disagree what evidence do you cite?

        3. Hello Mike Groves, You have had my name for a couple of days now, any chance of giving me an answer to the question?

  3. It’s easy to jump to the obvious conclusion as to why no harriers bred successfully since 2006, but it’s not necessarily a robust scientific case. Personally I believe that persecution by gamekeepers is by far the most likely factor, but there are aspects of the data presented which puzzle me slightly. Why were only 4-5 home ranges checked up to 2006, when according to later results at least 30 home ranges were known? Assuming around 25 home ranges were not checked in the early, apparently successful years, the sample statistics for those years imply that the occupancy rate was exceptionally high, and that far more than the recorded 22 young were likely to have been reared. Barring some winter disaster in 2006, we could expect a high level of home range occupation by breeding harriers in the more intensive survey of 2007, but none was recorded. Can RSG members come up with an explanation of these unlikely figures? I am not, as some in the shooting lobby might, implying that any dishonesty or incompetence is involved. I am a member of a Raptor Study Group myself, and aware of the integrity of all members of Scottish Raptor Study Groups. In any case, the results from 2008 onwards strongly agree with the 2007 findings. My point is that it seems unlikely that such a wipe-out of a potential population of 30 breeding pairs, and their progeny from the 2003-2006 period, could be achieved in one autumn and/or early spring by gamekeepers, especially without anyone noticing. I’d be interested to hear an explanation for this apparent anomaly. This is not a challenge; I’d be genuinely interested in a realistic hypothesis. I have my own ideas, but don’t want to sow any seeds at this point.

    1. Hi Jack,

      The failure of hen harriers to breed in the Angus Glens since 2006 coincides with a period of renewed intensification of grouse moor management in this area.

      Coverage of home range monitoring likely varied due to the availability of fieldworkers. As you’ll be aware, RSG fieldworkers (who provide the majority of the data presented by the SRMS) undertake their monitoring in a voluntary capacity – most of them have jobs, families, other constraints on their time etc.

      What stands out for us, apart from the shocking breeding failures since 2006, is that fieldworkers still monitor so many of these home ranges to collect these data. Can you imagine how depressing it must be for them, to go back to these sites year after year and find absolutely nothing? All credit to them for continuing to document this holocaust.

      1. Thanks RPS, unfortunately I’m all too familiar with the depression associated with monitoring Hen Harriers, and my own team of RSG volunteers have had several years recent experience of empty moors. I hear what you say, but would still be interested in what local raptor workers think caused the apparent massive crash between 2006 and 2007. Surely the gamekeepers couldn’t be that efficient, or we’d have even fewer harriers nesting in Scotland as a whole? Taking into account recruitment following several years of moderate breeding success, we could speculate that keepers would have to eliminate anything up to 100 or more harriers in one season to produce zero results in 2007. It seems highly unlikely that RSG members randomly just happened to check the only four occupied home ranges in 2003-2006. Was the renewed intensification of grouse moor management universal across the entire Angus glens, including what would amount to a monumental effort by an enhanced force of gamekeepers? How could they wipe out so many without any RSG worker or anyone else witnessing or finding any evidence? I appreciate your tribute and respect to RSG members as a whole, but there appears to be something very strange going on in the Angus glens. I’m convinced it involves illegal persecution, but that can’t be the whole story.

        1. “Surely the gamekeepers couldn’t be that efficient, or we’d have fewer harriers nesting in Scotland as a whole?”

          We DO have fewer harriers nesting in Scotland as a whole – the 2010 national survey showed a 20% decline in the Scottish HH breeding population! See here:

          It’s also worth reading Brian Etheridge’s account of the status of HH in Scotland:

          And the problem isn’t just in the Angus Glens. Read Fielding et al’s 2011 Hen Harrier Conservation Framework:

          Click to access jncc441.pdf

          That report is unequivocal that illegal persecution on driven grouse moors in central, eastern and southern Scotland is the primary cause of breeding failures in HH in those regions.

          1. RPS, I’m getting a bit worried that you’re picking up the wrong vibe from me. I’ve been intensively monitoring and researching Hen Harriers for the past 18 years, was responsible for the establishment of a harrier SPA, am familiar with the reports you’ve provided links to, and am fairly confident I know what I’m talking about. I was a founding member of the Raptor Study Group in the 1970s. I thought I knew who you were, and that you knew who I am “in real life,” but I appear to have been mistaken. I am fully aware of the results of the 2010 national survey, and the earlier ones. My statement which you’ve quoted above was perhaps not as clear as it might have been; I was suggesting that there would be far fewer harriers than were discovered in the 2010 survey, if gamekeepers were efficient enough to wipe out possibly over 100 harriers in the Angus glens in the course of one season. I was certainly not disputing that illegal persecution is the primary cause of breeding failures by Hen Harriers on driven grouse moors, and I made that perfectly clear. I know Brian and am familiar with his published works. I am resisting the rather obvious explanations for the catastrophic crash in harrier numbers in the Angus glens, for no other reason than not wanting to provide information that could be twisted into ammunition by the grouse shooting industry. You and I are on the same side. I simply have been trying to clarify whether any of the RSG members involved in the monitoring can provide an alternative explanation. Are you really seriously implying that persecution alone could have wiped out a potential population of 25-30 pairs of Hen Harrier (and potential recruits) in a single season? I find that proposition unrealistic, based on almost 40 years of experience knowing what my local gamekeepers are capable of with regard to harriers. The Angus glens must be employing “super-keepers”!

            1. Nope, not suggesting that gamekeepers wiped out a potential population of 25-30 pairs in a single season. We haven’t seen any data to suggest that such a high number of breeding pairs were present in the Angus Glens during this period.

              What we are suggesting, based on the SRMS data and evidence from other scientific reports, is that persecution in the Angus Glens (and in other areas dominated by driven grouse shooting) has gradually eroded the local HH breeding population and, since 2006, not one single breeding pair of HH has been recorded on these grouse moors.

              Are gamekeepers efficient raptor killers? Yes, they are, especially when they’re provided with high quality night vision equipment to take out roosting HH. But you already know this.

              You’ll no doubt be interested in a forthcoming paper on HH breeding failures in Aberdeenshire and the relationship with driven grouse shooting in that region – not yet published but due shortly hopefully – it will make your jaw drop, even though you are already very familiar with the overall HH situation in Scotland.

              1. The confidence limits may be rather wide, but if only four out of thirty home ranges were checked in 2003-2006, is it not reasonable to predict that a majority of home ranges were probably occupied in those years? Then in 2007, 15 home ranges were checked but they were all unoccupied. That strengthens the statistical probability that a sizeable population was wiped out completely in one season. Sorry to repeat myself, but I still feel that the data don’t add up. As you say, I am aware that gamekeepers are efficient killers, but not that good. Please be assured I’m not just being argumentative, and I’m eternally grateful to you for keeping the issue of raptor persecution alive and kicking.

                1. Not expert on these issues at all!!! However, re efficiency of keepers in removing hen harriers. If we assume, and I think it’s a safe assumption, that the loss of the five male hen harriers in England last year that just happened to disappear into thin air was a co-ordinated action by various parties, with subsequent anti RSPB propaganda from various papers associated with grouse shooting, then surely a very quick and ‘efficient’ killing of a lot of birds over a wide area isn’t that difficult. If highly protected birds can still be nobbled, what chances for them on hostile grouse moors? Couple that with high tech equipment, which I imagine the users of are becoming very proficient in, more so than we might possibly guess then what might seem highly unlikely population crashes from persecution alone might not be that unlikely. Certainly enough hatred for it. What other plausible causes could there be? Occam’s razor?

                  1. I, too, am no expert on these issues but my wife and I were involved in monitoring hen harrier nests in an Angus Glen from 2002 to 2005. We watched these nests almost daily and were well known to local gamekeepers. We were frequently “on the hill.” We had also reported an illegal trap and the estate in question received an official warning from Tayside Police and were informed that any more offences would lead to prosecution. We found and reported another illegal trap shortly afterwards but no legal action was forthcoming. I was then assaulted by a local gamekeeper for the second time and he received a warning from the Police. However I again had to report him to the Police shortly afterwards for further harassment. A short time later he left his employment to move to an SNH Estate in Aberdeenshire. The consequences of these clashes led to a situation where we had to give up our house tenancy in 2005. A camera had been set up in a neighbouring house where my wife and I were filmed every time we accessed our garden and I over reacted during a period when I was recovering from abdominal surgery. This, of course, meant we could no longer daily keep an eye on the moors which had almost become our second home. This situation, in effect, left some previously well monitored area two dedicated watchers short and also a situation of hostility between myself and the gamekeeping community. Land also changed ownership around that time and what many of my peer group saw as a “new regime” moved in. I still possess all the correspondence from that time detailing my meetings with Tayside Fire Brigade, Tayside Police and also a meeting between a local Estate Factor, my lawyer, myself and my wife. Now this whole situation might be meaningless in this context but one thing is for sure and that is relations between myself and my friends and estate workers were at an all time low. The previous two years we had monitored successful hen harrier nests which produced young but have been led to believe that since then no hen harriers have successfully fledged from that area.

                  2. Les, I answer your question very reluctantly for rather obvious reasons, but between 2006 and 2008 an apparently healthy and secure population of 12-14 pairs of Hen Harrier rapidly disappeared from my main study area. The site, an SPA, was no longer being keepered or shot for grouse at this time. Some disingenuous pro-shooters tried to lay the blame for this at the lack of fox control, but hill farmers and the local “fox club” were still actively taking foxes, and there was no evidence to suggest that predation by foxes had increased significantly.

                    The disappearance of the harriers coincided with serious drops in the numbers of Buzzards and Kestrels, the latter from ten pairs to only one; those species are not affected by fox predation. Short-eared Owls also became locally extinct at the same time. Fortunately we had been monitoring field vole population densities as part of a larger project, and recorded an enormous crash in the overall population the year that the raptor decline commenced. Even by 2015 the vole population had never shown any significant sign of recovery, and only in the past two years have Kestrels risen to three pairs (but with very poor productivity). Even more worrying, the vole crash seems to have been exceptionally widespread, and throughout the Clyde recording area Buzzard numbers halved in the space of a decade, and Kestrels declined by an alarming 90%. The Hen Harrier shortage was also reflected widely in southern Scotland, not just on my study plot. A slight recovery was recorded in a few areas in 2014 and 2015, but nearby results from Central Scotland, Lothian and Borders were very poor.

                    The correlation between vole populations and harrier breeding numbers is well known, but I find that due to limited research on the field vole side of the equation, the possibility of significant natural fluctuations may have been underestimated. As scientists we need to be as transparent as possible, and admit that natural factors can also affect harrier population dynamics. However on the larger scale the evidence is overwhelmingly clear that the main anthropogenic cause of breeding failure, and the overall factor inhibiting population recovery to favourable conservation status, is the ruthless persecution by man that the species endures.

                    1. Ahh..that’s interesting. Know that on Orkney they changed the way they farmed for a while and that had a knock on negative effect on the voles and thereby harriers. No voles on Shetland at all and no breeding harriers (I think?). Yes not being aware of this or acknowledging it would not be good.

                      I do think that if heat sensitive cameras are being used to track harriers then the people doing so may well have developed a proficiency in their use that would shock and surprise us and give them a hell of a capability to knock off raptors at a very good time to do so. I can imagine – but obviously have no practical reference what so ever – that a lot of birds could be ‘cleaned out’ over a wide area quite quickly especially with co operation between estates. Thanks for the info Jack, much appreciated and very illuminating.

                2. I did wonder about the years with low levels of monitoring and wanted to ask what was the likelihood of nesting HH going unnoticed in these areas despite the omission of an official survey?

                  1. Hi Andrew,

                    Yes, it’s entirely possible that breeding HH went unnoticed in the years of low survey coverage.

                    The main point though, as you’ve clearly grasped, is that coverage since 2010 has been v good and yet, no records of breeding HH.

                    We can be sure that had any HHs managed to breed successfully during these later years but had somehow escaped the attention of the fieldworkers, the grouse-shooting industry would have been shouting about these nests from the rooftops to demonstrate how great their grouse moors are for HHs. Interestingly, they’ve all been strangely quiet about it…

                3. Jack

                  I can see where you are coming from and that you would like identify the reason for the sudden decline and I fully accept that there may be reason(s) other than persecution however,

                  Maybe a new sporting manager took over?
                  Maybe the winter roost was found and a large number of birds were killed ?
                  Maybe the keepers acquired thermal imagining equipment?

                  Certainly the complete absence of enforcement in this area will be contributing to crime levels.

                  Maybe it is a combination of all of the above.

                  1. Can I add a few words of caution here. (not in direct response to CS above but generally to all posts and comments. It just seems to fit in here right now)

                    Nobody needs to worry about admitting there are other reasons that control population density. We don’t need to and shouldn’t be defensive about it.

                    We just need to focus on the levels of illegal persecution that cannot be denied and the fact there has to be more unseen persecution.

                    The big point is if it looks at all like we want to deny other factors it detracts enormously from the credibility of everything we say.

    1. A HH (hen harrier) home range is an area where the species lives but isn’t actively defended. A home range is usually larger than a ‘territory’, which is the area actively defended by the breeding pair.

      So in the context of monitoring HH in the Angus Glens, fieldworkers will visit known home ranges (i.e. large areas where the species has previously been recorded) and they will be searching for signs of breeding within that home range (e.g. courtship displays by sky-dancing males, food passes between males and females, or an actual nest).

  4. That’s what I thought. What puzzles me is the contradiction in sites looked at in 2002 to the amount now. Since this just started in 2002, how can anyone be sure that the monitored sites are actual HH home ranges if there hasn’t been any sighting for 10 to 20 years? Particularly where it says here that they weren’t looked at.
    Not that I disagree with the severe lack of Harriers in parts of the Angus glens, but not all estates changed to kill all and some areas aren’t shot. Ive seen and know of harriers seen in some of the non killing field estates so find it surprising that there is a declaration of 0 nesting sites.
    I understand the possible conflict with showing your hand, but it may be a good idea to put up a map with all the sites surveyed.
    It might eve be worth putting in a few anomalous sites in the worst estates, just keep them on their toes.

    1. Don’t confuse the start of the SRMS in 2002 with the start of hen harrier monitoring in Scotland! The SRMS wasn’t the beginning of monitoring efforts – it was the beginning of partnership working between different agencies and NGOs to pool their monitoring data and ensure consistency in the way those data are collected and analysed.

      Many bird species, hen harriers included, have been monitored for a long, long time, well before 2002. Just have a look at Donald Watson’s monograph on the HH (published 1977) to see how much detailed historical information was available, even then, about breeding sites. The Raptor Study Groups, who got going in the 1980s, will also have a serious amount of data from more recent decades.

      You’re right, HH can be seen in some areas of the Angus Glens, and indeed some estates disingenuously use these sightings as ‘evidence’ that their grouse moors are ‘supporting’ hen harriers. However, it’s one thing to have a record of a hen harrier flying overhead but it’s quite another to have a record of a successful breeding attempt.

  5. RPS, I realise your intention was to define home range as simply as possible, but in doing so I think those unfamiliar with Hen Harrier behaviour may be slightly confused. A home range isn’t just any area where a harrier lives but isn’t actively defended. In winter, for example, such an area could be very extensive, involving a bird foraging over an area of up to 50 square kilometres. Typically, wintering birds roost communally, and can travel very long distances while hunting during the day. To be pedantic, the term ‘home range’ is usually used to define the area within which a breeding pair forages from its nest. These can also be quite extensive, but for the purpose of defining SSSI boundaries, for example, the rule of thumb is a radius of 2km from the nest. Males tend to have larger home ranges than females, and of course these ranges are rarely if ever perfectly circular! So in effect, a home range is an area of suitable habitat which can provide sufficient prey for a pair of harriers to breed successfully. These are normally defined by the harrier surveyor progressively over a period of time, as the size may vary depending upon biomass density of prey species as well as topography.

    The term ‘territory’ in the case of Hen Harriers applies to the nesting territory, which is also difficult to define precisely, but can generally be described as the vicinity of the nest. These are usually defended by males against rival males during early occupation, and also by the female once pair bonds have been established. The situation can be complicated by the occasional semi-colonial nature of nesting harriers, and it is not particularly unusual for two nests, each occupied by pairs, to be several hundred metres apart. Polygyny, which is not particularly common away from Orkney, can lead to even closer nesting females.

    I’ve gone into such detail in the hope that I can illustrate why the Angus glens data is to some degree difficult to interpret. I hope I haven’t just caused more confusion. I still suggest that the data for 2003-2006, i.e. 100% occupation of all home ranges checked, albeit a small sample, indicates that the overall breeding population was probably healthy during that period, with a potential of up to 25 pairs possible (according to the later estimated number of ‘home ranges’). I accept that it is highly likely that the reported renewed intensification of grouse moor management led to increased persecution of harriers, but that the number required to be killed to bring about zero occupation of 17 territories in 2007 is simply not feasible. If that actually is possible to achieve in one season, whether helped by new technology or not, then the future is indeed bleak for the survival of Hen Harriers in Scotland. I don’t doubt that illegal persecution is the over-riding obstacle to harrier recovery, and needs to be eliminated, but we should also consider other possible factors affecting population dynamics, some of them attributed simply to ecology.

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