Four Hen Harriers Mysteriously Disappear


Game Birds / Thursday, November 22nd, 2018

Northern Harrier (Circus hudsonius) doing acrobatics
Four satellite-tagged hen harriers in Scotland have disappeared in just ten weeks. Their vanishing act is viewed as suspicious by the RSPPB. The news of the birds’ disappearance has come shortly after figures were published demonstrating that crimes against birds in Scotland have fallen.

Disappeared over grouse moors

RSPB Scotland have appealed for information after the rare birds that they were monitoring dropped off the radar. The conservation charity has described the losses as devasting given that the hen harrier is struggling. The police are also investigating the disappearance of the birds and the focus of the investigation has turned to the grouse moors of Aberdeenshire, Perthshire and the Highlands.

Satellite tagging

Satellite tagging enables scientists to identify which areas are important to birds for feeding, roosting and nesting. The birds’ movements can be followed in detail and the tags are fitted by trained fieldworkers. The small devices are designed to transmit even after a bird has died. But the tags of the four missing harriers stopped transmitting, raising suspicions of illegal activity.
The tags of all four birds had been functioning completely normally before they suddenly stopped transmitting. The only conclusion that could be drawn is that the devices had been tampered with.

The missing hen harriers

The first hen harrier to disappear had been named Athena. Her last known position was on a grouse moor located a few miles north-west of Grantown on Spey. A second bird called Margot disappeared two weeks later. Her last known location was also a grouse moor, this time on the border of Aberdeenshire and Moray.

A third bird, named Stelmaria, was last recorded on grouse moor north-west of Ballater a couple of weeks after Margot vanished. The fourth bird, Heather, was last detected on a grouse moor in Perthshire and disappeared three weeks after Stelmaria.

Crime against wildlife falling

News of the missing birds hit the headlines after new figures from the Partnership for Action Against Wildlife Crime Scotland were published. The figures showed that illegal acts against birds of prey had fallen 36% in 2017. The incidence of poisoning in particular, had fallen dramatically.
Dr Cathleen Thomas, who is project manager for the RSPB’s Hen Harrier LIFE project explained that the loss of the hen harriers has been devastating for everyone involved in the monitoring program. It is the illegal killing of the birds which represents the gravest danger to their population.

The gamekeepers’ response

A spokesman for The Scottish Gamekeepers Association said: “Until the findings of satellite tags are monitored by independent experts or bodies, we will never fully understand what happens when tags lose transmission nor will anyone be any closer to being able to do anything about it.”

The organisation has refused to speculate further as to the fate of the birds. There have been many cases of tags ceasing transmission when birds have last been recorded far away from any grouse moors. In some of these cases, the tags were never recovered.

Nonetheless, the RSPB remain suspicious of the grouse moors and believe that the loss of four birds over them in such a short space of time cannot be coincidental.