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Hen harrier monitoring, tagging and satellite tracking – latest data published

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Hen harrier

For many years Natural England has been involved with monitoring, tagging and satellite tracking hen harriers. To date, more than 60 individual birds have been tagged by Natural England, helping to determine their fortunes and inform our wider hen harrier conservation work. Updates on the status of all birds carrying Natural England tags are posted on this page periodically.

Birds tagged in previous years

In 2021, 31 pairs of hen harriers attempted to breed in England, of which 24 were successful, and 84 chicks fledged. This year, we have been able to follow the fortunes of 14 adult birds carrying transmitters fitted in previous years. We were pleased to see five of the older, more experienced birds - Dru (tagged 2017), Frank (2018), Sofia (2018), and Colin (2019) - attempting to breed in England in 2021, as well as Sorrel (2016) attempting to breed in Scotland. Dru’s and Sofia’s nesting attempts failed, as the nestlings were taken by predators, but Colin bred successfully, raising four young, and Frank successfully bred with two females, meaning he has now fathered 21 chicks in his lifetime. Although Colin’s tag stopped transmitting in April 2021, he was photographed and positively identified at the nest.

The remaining nine adult birds tracked during the 2021 breeding season were all one-year-old birds, hatched in 2020. Of the three of these that were wild-reared, one (Susie) bred successfully. The other six were brood managed birds, reared in captivity, of which five attempted to breed and four successfully bred, raising seven chicks between them.

Birds tagged this year

Of the 84 chicks that fledged in England, 17 were fitted with satellite tags by NE. Seven of these were brood managed birds (Moorland Association tags), and ten were wild-reared birds. Two of the wild-reared birds tagged this year were the offspring of the 2020 cohort of brood managed birds.

As of November 2021, all tagged birds have settled into their winter ranges. Some remain within their breeding areas, others migrate short distances away from the breeding grounds, and some winter abroad. Two of the 2021 wild-tagged birds (Rodney and Pete) have crossed to France, while all other birds remain in the UK, though one brood-managed juvenile appeared to set off across the channel before turning back and returning to southern England.

End transmission

Since the last update in July, we have stopped receiving movement transmissions from five of the satellite tagged birds: Asta (2020), Josephine (2021), and three of the 2021 brood managed birds. While it is not uncommon for birds to die from natural causes, particularly in their first year, hen harriers are also lost to illegal persecution. Therefore, when we stop receiving movement transmissions, the police are informed, and immediate efforts are made to locate and recover the birds on the ground. This is not straightforward, as the final transmissions from the tags do not always give a precise location.

Following intensive search efforts, the bodies of two of the 2021 brood managed birds have been located and, following our standard procedures, sent for post-mortem examination. The finding circumstances did not suggest that the birds were illegally killed, but should any information come to light about the cause of death that could suggest illegal activity, we would work closely with the police on the appropriate course of action.

Tags for the future

As of November 2021, 25 birds are still being tracked, plus Colin, who was known to be alive this year even though his tag has stopped transmitting. We will be publishing our next update on these birds in spring 2022. We are grateful to our staff and collaborators who work on tagging and monitoring for their considerable efforts.

Note on satellite tags: The satellite tracking devices are solar-powered, lightweight transmitters, and can give the locations of the birds to an accuracy of within 150m. They are attached by a harness while the birds are nestlings and are designed to transmit for several years. The harnesses are designed to eventually break and fall off.

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  1. Comment by Rob Yorke posted on

    Informative stuff. I witnessed 7 hen harriers coming into the moorland winter roost (on the ground!) at Druids hide, north Yorkshire in November 21.

    good piece in the Guardian (Dec 21) on gamekeepers who built the hide and are working with Natural England on the ground

    Rob Yorke

    • Replies to Rob Yorke>

      Comment by Alec Swan posted on

      Whilst it is genuinely NOT my intention to provoke or in any way antagonise Wild Justice ~ Raptor Persecution UK or those who lay the constant barrage of accusations that all BOP deaths are due to man and his persecution of them ~ I do hope that the supposed trinity of Ms. Tingay and the Messers Packham and Avery read this report, consider its source and assimilate the contents, and perhaps even, in the future, containing their outbursts to what is evidenced and factual.

      • Replies to Alec Swan>

        Comment by Keith posted on

        Raptor Persecution UK (or Wild Justice) has never claimed that "all BOP deaths are due to man and his persecution of them"

        And, to be perfectly honest, I trust the information provided by Raptor Persecution UK a great deal more than these occasional selective statements provided by NE.

      • Replies to Alec Swan>

        Comment by Da posted on

        Can you do me a favour, Alec? Post a link to where any of those people have ever said “All BOP deaths are due to man and his persecution of them”? Your opening sentence said you didn’t want to provoke or antagonise, so why then would wilfully post false information?

  2. Comment by Darren Chadwick posted on

    This is great information. The brood management system, though not universally embraced, is proving to be a very successful way forward. Credit to the moor owners and gamekeepers supporting this endeavour and of course NE despite all the aforementioned being criticised and even taken to court over it. Good to see productive cooperation working for the hen harrier.

  3. Comment by David E posted on

    Great report, factual and informative. Glad to see that there are not any accusations directed at people involved in moorland management when tags stop transmitting, but you endeavour to ascertain the cause and look for the birds. Unlike some other organisations who publish blogs, post on social media accusing owners and employees of persecution before any facts have been established causing friction.
    Positive results from collaborative working, looking forward to seeing results from next year.

  4. Comment by Mike Groves posted on

    Fantastic to witness this progressive change of attitude and breeding success in England of this iconic moorland raptor. A combination of collaboration, common sense and rightful positive recognition should hopefully see this fantastic bird of prey continue to move from strength to strength.

  5. Comment by Nick Cole posted on

    The "trinity" mentioned above recenly brought gamekeeper Hilton Prest to justice for his illegal raptor persecution.

    Perhaps if the NGO had fully engaged and helped drive, or fund, this prosecution there would be a little less suspicion of gamekeeper activity on driven grouse moors.

  6. Comment by MGS posted on

    Interesting update. It would be even more useful to see some graphs of the numbers fledging each year (both wild and brood meddled) and the numbers of birds still alive a year later and up to the current date rather than having the data buried in an excel spreadsheet several links away.

    That way it would be obvious whether the overall population is increasing year-on-year or not - and I assume that is the goal - to increase the UK population of this species?

  7. Comment by david mitchell posted on

    Come on NE . Have you no backbone ! What happened to that hen harrier ?

  8. Comment by Da posted on

    There are at least 57 Hen Harriers that have mysteriously ‘disappeared’ in the last three years, which the apologists in this comment section, as well as Natural England themselves, seem to have completely ‘forgotten’ about. No amount of puff piece blogs changes that fact. We’ve also seen yet another conviction of a gamekeeper for yet another instance of starving a raptor to death due to gross negligence (this time, a Sparrowhawk). The idea that this profession in any way ‘conserves’ wildlife is a complete joke, because amidst the propaganda being laundered through this blog, this was a record year for reported raptor persecution incidents. If Natural England was ever truly independent, those days are a long gone; whether it’s supporting disgraceful brood meddling schemes or making outrageous claims about a Hen Harrier being shot away from a grouse moor and then flying back on it (how on earth would Stephen Murphy know this?), it’s clear that they’re completely compromised and their first priority is not wildlife and certainly not the long term health of our raptors.

  9. Comment by Tony Powell posted on

    Start tracking the officially rare Woodpigeons next or at least assess their numbers more effectively as all the countryside and birders (not all of them) will disregard any meaningful recoveries we actually achieve.