Satellite-tagged hen harrier Tarras ‘disappears’ in Peak District National Park

‘Tarras’, a young hen harrier from this year’s Langholm cohort, has ‘disappeared’ in the Peak District National Park.


The following statement has been issued on the Langholm blog:

We have concerns for ‘Tarras’ a young female Hen Harrier tagged by Stephen Murphy (Natural England) at Langholm this summer.

The transmitter on the juvenile Hen Harrier Tarras has not transmitted since the 23rd October. The area has been searched and nothing was found and no hen harriers were seen in the area.

The last known fix area is on land owned by United Utilities in the north Peak District.

Tarras flew south from Scotland in the last weeks of September, arriving in the Nottingham area on the 11th October. She then headed north through Staffordshire and was roosting in the Peak District, near to the last known fix area on 13th October.

Tarras’ transmission period (duty cycle) was regular until 23rd October; on 23rd October it ran a complete transmission period (e.g. no sudden cessation of data within the 10hr transmission period). The local weather in the days immediately after 23rd were damp and overcast so this can delay the recharge time. However, by 26th concerns were raised. We have some evidence that suggest this may be a tag failure and we are currently trying to gather more information to help us resolve this.


That final sentence is a bit strange, and is at odds with what has been reported about the tag’s last smooth-running duty cycle. It’s worth revisiting a comment about tag reliability made recently by experienced researcher Dr Raymond Klaassen, who has been using satellite tags to track the movements of Montagu’s Harriers:

Technical failures generally are rare. We have recorded a few throughout the years (6% of all cases), however failures have always been preceded by irregular transmission periods and, most importantly, a drop in battery voltage (another parameter monitored by the transmitter). This makes it relatively straightforward to distinguish between a likely mortality event and a likely transmitter failure“.

So, given Tarras’ tag was not transmitting irregularly prior to her disappearance, what ‘evidence’ does Natural England have to ‘suggest this may have been a tag failure’?

It’s all a bit vague, isn’t it? A bit like the information put out about hen harrier Rowan who, according to Cumbria Police, was “likely to have been shot” in the Yorkshire Dales National Park.

We look forward to a timely update from Natural England about Tarras’ disappearance in the Peak District National Park.

UPDATE 16 March 2021: Interestingly, ‘Tarras’ is not listed on Natural England’s database of satellite-tagged hen harriers – why is that? See:

23 thoughts on “Satellite-tagged hen harrier Tarras ‘disappears’ in Peak District National Park”

  1. Interesting. Perhaps need to tell our Scottish Hen Harriers to steer clear of Northern England rather than worry about the failure rate. See more comment s from Stephen Murphy of Natural England who quoted 4% in to the Eskdale and Liddesdale Advertiser. Why we can’t see a track ending at a United Utilities Estate is a bit strange (or not).
    The link has now failed, but here is what was said:
    “There is also concern for Tarras, a female hen harrier tagged at Langholm this summer. The transmitter has not transmitted since October 23. The area has been searched and nothing was found and no hen harriers were seen in the area. The last known fix area is on land owned by United Utilities in the north Peak District.

    Tarras flew south from Scotland in the last weeks of September, arriving in the Nottingham area on October 11. She headed north through Staffordshire and was roosting in the Peak District. By the 26th, concerns were raised.

    Stephen Murphy of Natural England who has run the satellite-tagging project in Langholm since 2008, said a bird with a tag had been spotted about 20km to the north. He had checked with an organisation in Ireland which tagged harriers but it was not one of their birds so it could be Tarras.

    The tags are solar-powered and the British weather is not always conducive to their operation. About four per cent of them fail. They can be no more than three per cent of the birds’ bodyweight so are restricted to about 350 to 400gms.

    They transmit every 14 minutes, 10 times a day. The technology allows Stephen to pinpoint the bird’s location within a 150 metre area but if it is on the ground, that drops to about 50 metres.

    Stephen said: “It has been a fascinating journey to see the landscape through the birds’ eyes. A lot is known about them during their breeding season but not what they do outside that time.

    “We wanted a full history rather than snapshots and some of the findings are incredible. We’re learning with every bird tagged. One of Langholm’s birds ended up in Spain.

    “The harrier has been described as a bird of the mountains which disperse to the coast in winter. This work is showing that they are hardy and stay in the mountains year round.

    “Hattie and Grainne have stayed in Langholm; they are three and half years old and have reared young successfully with my tags on.”

    Stephen said the people of Langholm should be commended. It was a real shot in the arm to see the birds there.

    He said a lot of good had come out of the Langholm moorland demonstration project, which introduced diversionary feeding for the harriers and proved this could reduce the number of grouse taken, allowing the grouse to thrive.

    He said: “It’s difficult for people not to be partisan but it’s time for change. Harriers have to be a part of the moorland management system. Gamekeepers want us to work towards a solution which includes them. It could include brood management and translocations.””

    1. “This work is showing that they are hardy and stay in the mountains all year.” No, they are clearly not a mountain species so much as an upland bird, which is why brood management and translocation is surely naive in that they will always travel and gravitate back to the uplands to suffer the same fate as these birds.

  2. I can understand why raptor fieldworkers are cautious when releasing such statements if they are not absolutely 100% certain of the facts.

    They only have to be wrong once and their credibility will be questioned on absolutely everything, past, present and future.

  3. To get a flavour of what all of this is for – millions of acres rotationally incinerated, other ventures and their associated economic value and jobs suppressed, overall loss of biodiversity, increased flooding and higher water treatment costs then take a look at this video – no condescending shite about looking after the moors and being a custodian of their willdife just 7 minutes plus of slaughter. Closest I’ll ever get to a grouse butt, no thanks.

    1. You can see why they need to turn the uplands into an intensive Red Grouse farm at the expense of everything else to support this barbaric and ridiculous hobby. The thing that struck me was the lack of clean kills other than flying towards the gun at close range, obviously the shooters are high on adrenalin and trigger happy, many shots were fired opportunistically into fast moving flocks beyond the normal 50 yard effective range of the shotgun so I expect a lot of birds would have been injured by a wide spread of pellets rather than killed.

  4. I seem to be responsible for comments being disabled on that video, having been sickened by the arrogance and smugness of the positive comments added regarding the outcome of the Westminster debate. Sheer gloating, and the usual outpourings of lies and obfuscation. My worst fear is that it will be harriers that suffer in the medium term, because these creeps are riding on the crest of a wave at the moment. I submitted two comments, expressing disgust but sticking to scientific facts and attempting to counter their arguments, and received the predictable abuse in return. Then “comments are disabled for this video”!

  5. It works both ways – yes, a culture has grown up where one side can say anything and get away with it but the moment a scientist puts a foot wrong all hell breaks loose – and it is clear people are being intimidated, let alone the fact that NE is completely muzzled by the same people.. BUT as far as I’m concerned, having followed the technical details of tagging if a tag stops transmitting suddenly my assumption is that the bird has been unlawfully killed – yes, there may be a tiny proportion of technical failures but the probability is even lower than completely natural failures of nests/ pairs that have not been interfered with.

    And yes, the persecutors may be crowing but actually they haven’t got much to crow about – they’ve succeeded in ensuring that RSPB cannot go back to the table with them, and whilst they may have delighted their own supporters, just how many new recruits have they made to their point of view ? Whilst further alienating anyone who was left thinking a solution short of a ban is achievable.

    And now – we already know HH is effectively extinct as a breeding bird in England – the Scottish population is being targeted in the already disgraced Peak District.

  6. Thanks for the link Les, even though it made me feel physically sick, So this what they call ;sport’ is it? Just like Winn-D the first thing that struck me within seconds was that the moron (and yes he was wearing a tweed jacket despite the derisory comments by the ‘pro’s’ in the ‘non-debate’ that this is what we ‘conservation activists’ keep claiming to be the case!) didn’t even take proper aim to ensure a clean kill. He just fired willy-nilly into the packs in the hope of killing (or maiming) something. I understood that there was a limitation to the number of birds taken. Who did the counting in that film!!!

    Re Tarras – was she by any chance the nest mate of ill-fated Rowan (also tagged by Steve Murphy on behalf of the Hawk & Owl Trust at Langholm?). Which leads me to the million dollar question (Rod). Did Merricks get re-elected as HOT Chairman at the AGM. I don’t seem to have heard any response from the HOT or Merricks and David Cobham regarding the killing of Rowan. Are they still all agog about the merits of brood management?

    No doubt Steve M. reads this blog, so can I just agree with him that we are indeed learning a lot about what happens to the tagged birds – yes indeed – all too many of them get shot on black-hole grouse moors having moved away from their natal sites. So Harriet and Graine stayed on L:angholm and bred. Great. I make that two. Now can you tell us how many of your tagged birds have gone missing? Please.

    One last blast. How come Dr Coffey already had the decision of the Government to “have no intention of banning driven grouse shooting” and “no plans to introduce licensing” on paper in her summing up – when the debate had only just finished? What with that fiasco and the preliminary hearing which amounted to a pre-arranged diatribe which to my eyes was full of libellous and slanderous attacks on Mark Avery and the rest of us, which if it had come from us would probably have landed us in court. I suspect the 18 Tories had all been given the same hymn sheets as they walked in!

    1. I’d like to know as well what happened at the 2016 HoT AGM. I can find nothing on their website and they haven’t replied to an email asking where the AGM report is. I also made a factual, polite comment on one of their news items about Rowan but they didn’t print it. Anyone still a member of HoT who can enlighten us?

  7. I am not sure but what I do believe is that if a tag is transmitting in the same place with no movement, it does usually mean the bird has died. If it has stopped suddenly then it can be a transmitter failure. An Osprey Blue YD his tag suddenly stopped and he was spotted returning from migration in the UK. Do Natural England no where the last transmission was as that could give a clue?

  8. I don’t support brood meddling in general, but it is a shame there is no way to get HH to breed on urban “green roofs” in cities and towns. Some of those roofs would be perfect as they always skimp on the maintenance and they start having heather and low growing shrubs on them whether they are designed that way or not. Moving into urban areas saved the peregrine and sparrowhawk (to the ire and chagrin of gamekeepers and pigeon fanciers), it is a shame there is no way to get hen harriers to take the same leap.

    1. I guess that certain birds will never become urbanised. I can’t imagine a Ring Ouzel, for example, nesting down my street.

      Whilst I’m on here…

      This probably sounds daft/naive but when a satellite-tagged bird is located on a monitor screen then what is the timescale from the satellite actually receiving the signal to the monitor showing the location?
      Surely there are enough interested people to want to follow these tagged birds and get on to the ground where the signal location shows for each day?
      Would there be less chance of a tagged bird being killed if more people spent more time in the area where the signals were showing?
      And more chance of catching someone ‘in the act’ if many eyes watched on?
      If I knew that a tagged Hen Harrier was in my area then I would be keen to spend time in the signal locations.
      Who actually does the monitoring of these birds?
      Naive or not?

      1. I believe the type of satellite GPS unit normally used for hen harriers has a recording frequency and transmit frequency of around 20 minutes and up to 3 days when the stored information is sent to the satellite. Thus if the bird dies in the long period it can travel a long way if the satellite is not visible at the start of the transmit period. If it is determined that the bird has died the transmitter reverts to a vhs signal detectable by a receiver over a few miles, or much further if the observer is airborne. Any light plane owners willing to volunteer of there? If the transmitter is then shot by the same person who shot the bird the transmitter, the bird and the information are all lost. Probably the main cause of failure, but way more than 4% unfortunately?

  9. Yesterday we wrote to Stephen Murphy at Natural England, seeking any further conclusions on the most likely reasons for the satellite tag failing over our local moors in the Peak District. Until we have further data, it might be wrong to jump to too many conclusions. However, recent video evidence of a gamekeeper with a hen harrier decoy on National Trust moorland does show that raptor persecution remains a very serious issue within Peak National Park, as does habitat and peat degradation associated with over-burning.

    Next Thursday the PDNPA will be launching its ‘State of Nature in the Peak District’ for 2016, prepared for them by Penny Anderson ( We hope they will make a clear statement on their concerns over raptor and mountain hare losses and habitat damage associated with intensive grouse shooting here.

    Meanwhile, our own coalition has so far gathered nearly 1,000 written signatures and another 2,500 online in an attempt to tell the National Trust NOT to reappoint another shooting tenant to their moorland estate around Kinder Scout and Bleaklow in the Peak District. (The current tenant, grouse manager Mark Osborne, is being evicted in 2018!).

    Please sign and promote our petition to help create an 8,000 hectare region free from grouse shooting and associated habitat and species destruction.

    1. The report is already available from that link. Taken from the summary:

      “This review has demonstrated the considerable extent of restoration work that has been and is being
      undertaken on the Dark Peak moorlands. There is still a long way to go to restore the full wetland
      functionality to much of the peat, but the results show we are heading in the right direction where work is
      being implemented. There is much that needs attention on the moors though, especially in the Dark Peak,
      related to issues of burning on peat and losses of birds of prey”

  10. Sorry ‘Moorland Vision’ I tried to get onto your blog to sign your petition, but the site is blocked (as sometimes is the case with RPUK when I try to link with it. Are you people being nobbled, or is it me?

    Still no news from the HOT so I’ll try a different avenue.

    Andy, I think ‘Cryptic Mirror’ had his tongue firmly in his cheek when he suggested ‘urban’ Hen Harriers. But wouldn’t it be great!

  11. So difficult (and costly) to get evidence and successfully prosecute. I recall doing a bucket collection for the RSPB in a large Tesco in Earls Court. I was approached by a plummy young man who verbally attacked me sneering about the RSPB because they want to protect raptors.
    I was very shaken by it – and have no doubt about why this is happening.

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