The female bird (Heather) was being followed by thousands of people online as part of a satellite tracking project run by the National Parks and Wildlife Service (NPWS).

Dr Barry Donoghue of the NPWS, who oversaw the satellite tracking programme, said it was “heartbreaking” to find the dead bird.

Before the bird was found dead he said he suspected the worst after noticing the bird’s sudden lack of movement on the tracking device and the dramatic reduction in her body temperature.

“I suspect it was a deliberate attack”, he added.

Donoghue had been tracking the bird since 2012 and he said she was expected to breed this year. She was killed in the place of her birth in south Kerry.

The satellite tracking was borne out of an interest in Hen Harriers by the local community. "Heather was named by local school children and taught by a man who is farming in the Hen Harrier SPA. It is so sad they have been robbed of the opportunity to see her continue in life as she should have," Barry said.

Hen harriers are a protected species in Ireland and it is an offence under the national Wildlife Act to kill them. If found the culprits could face a fine or imprisonment.