Tags allow researchers to monitor birds and investigate when they go missing.
More than 10 young hen harriers have been fitted with satellite tags this summer in Scotland.
RSPB’s Hen Harrier LIFE project tagged birds from the Borders to the Highlands, allowing them to be tracked as they strike out on their own.
Data from the trackers will give researchers a better idea of how young harriers behave in their first few years, and can be used by investigators if a bird goes missing.
A survey in 2016 put hen harrier numbers in the UK at just 575 territorial pairs, a decline of 24% since 2004. Estimates suggest there should be over 1,500 pairs of hen harriers in Scotland alone.
The RSPB said tagging allowed them to gain a much deeper understanding of hen harrier behaviour.
Two birds tagged in Scotland last summer flew to Ireland for the winter before returning this spring. One of the chicks tagged this year is the offspring of a female tagged in a previous year by the project, providing an opportunity to follow the species through two generations.
The tags also reveal when birds suddenly or inexplicably disappear or are illegally killed – almost always on or close to grouse moors.
Earlier this year RSPB Scotland appealed for information on the disappearances in areas managed for grouse shooting of two birds tagged by the project – Marci, who was last recorded in the Cairngorms National Park near Strathdon, and Skylar, who disappeared close to Elvanfoot. A third bird, Rannoch, was found dead in an illegally set spring trap on a Perthshire grouse moor in May.
Dr Cathleen Thomas, senior project manager for Hen Harrier LIFE, said: “It’s a real privilege to work with and follow the journeys of these incredible birds of prey and the sight of one of them skydancing never fails to take my breath away.
“However, very few people get to experience such a spectacle as the British Isles are missing 80% of the breeding hen harriers they could support. These birds face enough natural challenges in their first few years of life trying to avoid predators and learn how to hunt without the added pressure of illegal killing, shooting and trapping by humans.
“With Scotland the stronghold for the British hen harrier population, tagging these young birds here and understanding what is happening to them is crucial for our efforts to create a more secure long-term future for the species.”
An independent enquiry commissioned by the Scottish Government is currently undertaking a review of the environmental impact of grouse moor management and possible options for regulation. RSPB Scotland is calling for licencing of the industry to be introduced to bring an end to the continued illegal killing of birds of prey.
