Mike Shurmer, Head of Species for the RSPB in England, describes the success of hen harriers and the RSPB’s nature reserve at Geltsdale, and the important role played by diversionary feeding...

Firstly, we all welcome the news from Natural England that hen harriers have had their most successful season in England for several decades, with 31 breeding attempts, of which 24 were successful, fledging 84 chicks.

 It’s encouraging to see the successful breeding of pairs across a range of upland moorland landscapes, and we hope that this year’s figures represent a positive turning point for both hen harrier and the future of our uplands.

Across England there are many hundreds of thousands of hectares of habitat that are suitable for breeding hen harrier, and whilst we at the RSPB have over 100 reserves across the country with a range of habitat types, we only have a small proportion of the overall moorland landscape within our managed network. However, at special places such as Geltsdale, our dedicated staff and volunteers have been restoring blanket bogs and diversifying the rich mosaic of habitats and species that should be in these glorious settings.

Geltsdale is around 5,000 hectares and home to phenomenally rich upland plant life, invertebrate communities, as well as ring ouzel, black grouse, curlew, and of course hen harrier too.

Hen harrier story from Geltsdale in 2021

After a difficult start to the breeding season, we are delighted to report that four young hen harriers fledged from a nest at Geltsdale this year. This is the first time that harriers have nested successfully at Geltsdale since 2016, which in itself was the only successful nest in the last 15 years.

Sadly, hen harrier nesting attempts in recent years have repeatedly failed at the reserve, due to a parent bird disappearing away from Geltsdale at a crucial point during the breeding season. This pattern was repeated again earlier this year when two male hen harriers went missing. The police treated this as suspicious and issued a press release appealing for more information.

One of our fieldworkers at Geltsdale related that: “The unexplained disappearance of not one, but two provisioning males within the space of a week was a demoralising body blow to all involved in the intensive monitoring of the harrier nests over many hours and in all weather conditions. So it was an unexpected joy to find this late and ultimately successful nest.”

Knowing that the birds would arguably be safer if they were regularly hunting on Geltsdale, we used a technique called diversionary feeding once the chicks had hatched.

Diversionary feeding and how has it helped the hen harriers at Geltsdale

This technique has been rigorously tested, and our approach is based on best practice guidelines produced by Scottish Natural Heritage (now NatureScot) and from experience at Langholm Moor and in the Forest of Bowland. It involves providing a supplementary food source close to a nest for the adult harriers to feed to their chicks. This reduces the time that harriers spend hunting far away from the nest and means they are less likely to prey on red grouse when they are feeding young. It is also thought to help improve breeding productivity, by providing a regular food source and ensuring that the chicks are well fed through bad weather.

Hen harrier chicks hatch at different times, usually two days apart, and we only start diversionary feeding once all of the chicks have hatched. This is the point at which the adult female would usually start hunting away from the nest for food to provide to the chicks. At Geltsdale this year the chicks hatched between the 23 and 27 June, and we started providing food, in the form of farmed quail, once a day from 29 June. We started by providing small cut-up pieces, gradually increasing this up to a maximum of five farmed quail a day.

How we monitor the fledged young and the processes that the RSPB has to follow

The young harriers started to fledge on 26 July, with all young fledged on the 29 July. The harriers remained on site for another three weeks, with all juveniles looking healthy and active.

An essential part of hen harrier conservation work is to be able to monitor the young once they have fledged, and as such chicks were fitted with satellite tags on 21 July. These satellite tags have been shown to provide vital information on hen harrier dispersal and survival. The RSPB has recognised expertise in fitting these tags and has fitted over 100 to hen harriers in the last seven years.

Providing diversionary food to hen harriers in England requires a licence from Natural England and we’ve attached ours for transparency. As you can see, it lays out a number of conditions by which we have to abide.

The conditions act as a really important safeguard to ensure that diversionary feeding is done in a consistent way that fits with the latest guidelines and minimises any impacts on the harriers themselves. Reporting any planned activity to NE is one of these conditions.

This year the RSPB acted quickly to get diversionary feeding in place at Geltsdale, but we missed alerting Natural England at the outset. This was an error on our part and once it came to light we discussed with Natural England whether we could continue to operate under the licence. NE confirmed we could continue the successful diversionary feeding process as this was a technical breach with no intent on our part, and we have committed to the advice and adherence to the licence requirements going forward.

Good questions always need to be considered on the risk of disturbing adults on nests, hence the importance of these licences to carefully implement best practice. We follow these best practice guidelines and take confidence from our on the ground experience with wardens and estate teams that adult harriers carry on feeding their chicks and lead to successful fledging, whilst our satellite tagging and colour ringing work shows that adults that we have provided supplementary food to frequently return to breed at the same sites in subsequent years.

Hopes for the future

From a Geltsdale perspective it’s great to see how the birds we’ve looked after and safeguarded can support the wider breeding success in England. We’ve got a fabulous reserve that is restoring the health and diversity of wildlife and having hen harriers as a part of that fabric of nature in the uplands feels like a more promising and sustained reality.

From experience we know the fledged birds will face many challenges, both natural and human, in the months and years ahead so our hope is that everyone can keep pulling together in the acceptance and celebration of these true sky dancers.

Image: Hen harrier young at Geltsdale this year (picture taken under Schedule One Licence)

RSPB licence from Natural England:

WML-OR12 RSPB Organisational Licence 15 May 2020 - 31 January 2022 FINAL.._.pdf
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