Two hen harriers have been fitted with satellite trackers in the Isle of Man as part of an initiative to protect the species.

The detailed movements of siblings, Grayse and Mannin, are now being closely monitored by scientists.

Until recently, little was known about the seasonal or lifetime movements of hen harriers.

By tracking birds in the Isle of Man and across the British Isles, conservationists hope to gain a better understanding of the species’ behaviour.

The insight gained should enable more effective protection measures and conservation strategies to be put in place.

Aalin, a young female hen harrier, was tagged last year.

She was tracked leaving the Isle of Man in late summer, then spent the winter in Shropshire before partnering with a male in the Welsh hills during the summer of 2017.

After just one year, Aalin’s exploits already tell scientists that any conservation efforts must be joined up across different territories - and coordinated by the different authorities responsible for the many locations on which the birds might depend during their lifetimes.

The hen harrier is a swift and graceful predator is a regular spectacle in the Manx uplands during the summer and along the coasts and lowlands in winter.

According to research by Manx BirdLife (funded by the RSPB and the Department of Food, Environment and Agriculture), in 2016 there were 30 active nests on the island.

’This is half the size of the population just over 10 years ago and it is important for us to understand the reasons behind this decline,’ said Neil Morris, managing director of Manx BirdLife.

’Tracking the species’ movements will aid our understanding of how to safeguard the island’s population of this magnificent bird of prey.’

The tagging of Grayse and Mannin is part of a wider programme coordinated across the British Isles by the RSPB’s Hen Harrier LIFE+ Project team.

In the Isle of Man, Louise Samson, DEFA forestry warden, played the leading role in monitoring nesting hen harriers, with input from Manx BirdLife’s Emma Naldrett.

Louise found the nest with Grayse and Mannin in the uplands of the Isle of Man, to which James Leonard, a trained and licensed volunteer tagger, travelled from Scotland in order to tag them.

Louise said: ’Hen harriers have become an integral part of the beauty of the Manx uplands appreciated by both local and visiting wildlife enthusiasts.

’Satellite-tagging a brother and sister will enable us to watch these birds through their life journeys and monitor their habitat use, movements and interactions with each other as well as with other hen harriers.’

From September, those interested will be able to follow the progress of these special birds along with a number of other hen harriers as the RSPB charts their progress on the Hen Harrier LIFE+ project website. Visit www.rspb.org.uk/henharrierlife or follow the project on twitter @RSPB_Skydancer.

Manx BirdLife thanked John Francis and the Tesco ’Bags of Help’ scheme and to the Isle of Man Steam Packet for their support.

The team also thanked shoppers who voted in support of the project using their blue tokens in Tesco’s Douglas store.

Hen harriers had been persecuted to extinction as a breeding bird on mainland Britain by 1900, but managed to recover their population naturally. However, continuing illegal killing and disturbance threatens to drive the birds to the brink once more in England and parts of Scotland.

While the Isle of Man clings onto a reasonable - though declining - population of hen harriers, elsewhere their fate in the British Isles is extremely concerning. In 2016, just three pairs of hen harriers attempted to nest in England while numbers in Scotland fell by 20% between 2004 and 2010.