RSPB's Hen Harrier LIFE Project Manager, Dr. Cathleen Thomas gives an update on the class of 2017.
The winter months can be hard for young hen harriers, and it’s a worrying time to monitor them. With poor weather, difficult foraging conditions, and the risk of illegal persecution, every day they survive feels like a small victory. That’s why I am sad to confirm the natural demise of more of the class of 2017.
Back in August 2017, we proudly added the journeys of 12 young hen harriers to our project website where we provide regular updates on their movements. First we lost Calluna, who disappeared on 12 August on a grouse moor in the Cairngorms National Park. We were able to retrieve Mannin after his failed sea crossing from the Isle of Man on 14 August. On 18 October, Manu disappeared over moorland at Blenkinsopp Common, whilst Tony disappeared in Spain on 22 October. We also reported that Sirius died on 11 October, and we had managed to retrieve his body, but were awaiting the outcome of tests.
Sirius was a male hen harrier who, along with his sister Skylar, was one of three chicks to fledge from a nest in Argyll in July 2017, on land owned by Forestry Enterprise Scotland. Sirius and his siblings were the first offspring to be produced by our female, DeeCee, who fledged from Perthshire in 2016. On 11 October, our Investigations team monitoring Sirius’ tag saw that he had stopped moving. The team carried out a search and were able to locate and recover his body from a hillside near Loch Lomond. The post mortem examination revealed that Sirius had a fracture of the left radius and ulna, and indicated that trauma was the likely cause of death.
A map of Sirius’ final journey.
Sirius (image by RSPB)
During Sirius’ short life, he didn’t venture very far from his nest site in Argyll, in contrast to his sister Skylar, who travelled across to the west coast of Ireland before returning back to south west Scotland last autumn. It would have been interesting to compare the journeys taken by these siblings to see how they differ, especially since we are also tracking their mother, DeeCee, to see what it told us about the stories of related birds. Sadly, we won’t get the chance to do this anymore, but we will certainly be watching closely to see whether DeeCee or Skylar are able to raise chicks this year.
Sirius’ demise was compounded with the loss of Eric at the end of January. Eric was tagged on Orkney in July 2017, and after fledging remained faithful to mainland Orkney. He travelled to neighbouring islands Shapinsay, Stronsay, Copinsay and South Ronaldsay but spent the majority of his time in the east mainland of Orkney this winter.
On 27 January 2018, data from Eric’s tag, which continued to transmit as expected, showed that he had made a sudden and unexpected journey eastwards, away from the islands and out into the North Sea. Data from later that day then showed that he had gone down in the water, and shortly afterwards the tag ceased transmitting. All the evidence suggests that Eric drowned.
Alan Leitch, RSPB Site Manager for the Orkney reserves, said: “The loss of Eric is sad; it coincided with a period of bad weather on Orkney, so it appears likely the strong south westerly winds blew this young bird off course. The loss is particularly felt on the islands, as the bird was named in memory of our late friend and colleague Eric Meek.”
Eric’s journey
Eric (image by Alan Leitch)
The continued loss of these birds shows just how vulnerable this species is and the challenges they face even without the additional threat of illegal persecution. We will keep a close eye on our remaining female hen harriers from the class of 2017 and don’t forget that you can help by reporting your hen harrier sightings to us at henharriers@rspb.org.uk
This helps us to focus our monitoring and protection work in the right places, which is particularly important as we head towards the spring, when these birds will start their amazingly acrobatic skydancing and pair up with mates to produce the next generation of chicks.