A new and exciting interactive dashboard, allowing the RSPB to share valuable and important information on the outcome of tagged hen harriers.

What is happening to the UK’s Hen Harriers?

It’s a question the RSPB has been trying to answer. In recent years, satellite tagging has helped shine a light on where young Hen Harriers go after fledging and, crucially, the circumstances in which they die or disappear. 

Now this information is being brought together in a new interactive Map Hub, which displays all the fates of the RSPB’s satellite-tagged Hen Harriers going back to 2014. The easy-to-use dashboard makes it possible, for the first time, to see what has happened to each bird as well as providing information such as the name, the year and county the bird was tagged in, and photos taken during the tagging process.

You can explore the Hen Harrier Map Hub here: https://rspbeu.maps.arcgis.com/apps/dashboards/8377efb6ca064cfa91750b263af11f2f

The birds are recorded under one of five fates:

  1. Confirmed Illegal persecution
  2. Stop no malfunction (where the bird has disappeared in suspicious circumstances)
  3. Natural
  4. Unknown
  5. Tag failure/expired

Detailed definitions of these fates can be found within the Map Hub.

Currently the map show data for 178 Hen Harriers out of the 226 birds tagged so far. Hen Harriers which are currently alive and being monitored are not featured on the map. Additionally, the fates of some tagged Hen Harriers are not featured on the map hub due to them being subject to ongoing police investigations.

Jenni Burrell, RSPB Investigations Intelligence Officer, said: “We have been tagging Hen Harriers since 2014 and this wealth of research has provided us with so much information. It is exciting to be able to launch this new map hub and publicly share the data that has proven essential in our work.

“The RSPB has had the enormous privilege of being able to tag and monitor this vulnerable species to understand their movements and establish any patterns in behaviour (both breeding and roosting) and the fates that befall them. We have seen birds travel to and from Europe, return to their natal areas to breed or breed in different areas every year. We have seen a devasting pattern of birds disappearing or being illegally persecuted on areas managed for driven grouse shooting, whereas birds that die naturally are usually recovered. Hen Harriers are the most intensely persecuted birds of prey, and the tags continue to provide us with the facts that the persecution is continuing.”

This tagged female Hen Harrier, known as Chance, was fitted with a satellite tag in 2014 in South Lanarkshire, Scotland. Her tag data provided new insights into her movements revealing that she over-wintered in France twice. Sadly, on returning to her natal area to breed in 2016 her tag suddenly stopped with no malfunction in an area of grouse moor.

The satellite-tagging process

Satellite tags have become a key conservation research tool in recent decades. These small transmitters give fascinating, previously unknown insights into the lives of some species, revolutionising the study of bird ecology by tracking their movements. Data received from satellite tags has helped to identify important migration staging areas, and key nest and roost site locations, which has assisted in the implementation of effective conservation strategies.

From 2014-2024, the RSPB has fitted satellite tags to 226 Hen Harrier chicks before they leave the nest. These 226 individuals represent a fraction of the total UK population of Hen Harriers, as not all nests are visited and only one or two chicks in the brood are fitted with a satellite tag. The tags, which weigh less than 3% of the bird’s overall body weight, are harnessed to the bird's back using strong, lightweight Teflon straps. All satellite tags are fitted under Government licence via the British Trust for Ornithology by trained experts.

Mark Thomas, RSPB’s UK Head of Investigations: “We haven’t been able to do this alone and we are grateful to all those who have and continue to support us in this vital project.”

The RSPB would like to thank all those who have supported and continue to support the RSPB in tagging Hen Harriers; EU LIFE Programme who funded the RSPB Hen Harrier LIFE Project (2014-2019), tag sponsors & funders, tag fitters, landowners (allowing us to tag), BTO and raptor study groups.