An appeal for information has been launched over fears surrounding illegal killing after a rare harrier bird's GPS transmitter suddenly failed in suspicious circumstances.

The tag was attached to a young female Hen Harrier, named Helius, which hatched last summer in the Forest of Bowland.

While still in her nest she was fitted with a satellite tag allowing the Royal Society for the Protection of Birds to monitor her movements after flying the nest.

The tag had shown her exploring the Bowland Area of Outstanding Natural Beauty, on the United Utilities estate and neighbouring moorland, and she even had her own chicks - a brood of five hatched on United Utilities' land this summer, three of which fledged.

On July 31, Helius was tracked to the boundary of the United Utilities estate, between Brennand Fell and Tarnbook Fell, however the next day her tag failed to transmit and has been silent ever since.

This sudden failure has raised fears of illegal persecution of the rare, beautiful bird, especially after Lancashire Police and the National Wildlife Crime Unit were informed and their search found no trace of Helius or her tag.

Rare breeding birds in the UK, Hen Harriers are known for their acrobatic 'sky-dancing' courtship displays, but illegal persecution in recent decades has reduced its population to just a fraction of what it should be.

This year there were only 25 successful nests in England, a drop from 36 in 2023, while a Government scientific study estimates there is capacity for more than 300 pairs.

The RSPB has been tagging Hen Harriers for more than a decade to help with conservation efforts for this elusive and heavily persecuted species.

In 2023, 34 tagged birds were either killed or disappeared in suspicious circumstances, many of them in connection with land managed for driven grouse shooting. This is more than in any other year to date. 

Hen Harriers have 'unusually low' survival rates with illegal killing identified as a major cause in a study published in the journal Biological Conservation, with the birds spending time on land where grouse shooting takes place a significant risk factor for the animals.

Howard Jones, RSPB senior investigations officer, said: “Satellite tags continue to transmit even after a bird dies, allowing us to locate the bird’s body.

"But when a tag suddenly stops transmitting, with no sign of malfunction, and then cannot be located, this is deemed highly suspicious. We suspect human interference in this case. 

“Helius’ fate is by no means a one-off. Too many of these birds are disappearing in suspicious circumstances, and it is having a heavy impact on the species as a whole.” 

DI Mark Harrison, of the NWCU, added: “Bird of prey crime is a UK national wildlife crime priority, and crimes involving Hen Harriers and other birds of prey have no place in modern society.

"We will continue to work with the RSPB and our other partners to develop crime prevention techniques and thoroughly pursue all investigations into these crimes.

"The public also plays an important role in reporting intelligence and suspected crimes to the police.” 

Anyone who sees a dead or injured bird of prey in suspicious circumstances is asked to call police on 101 or report it online at the RSPB's website.

Those who wish to provide information on perpetrators anonymously are asked to call RSPB’s confidential Raptor Crime Hotline on 0300 999 0101.