Back in 2016, the National Trust for Scotland (NTS) was celebrating the rare success of a hen harrier breeding attempt on the Mar Lodge Estate, the first such success for decades (see here).
[A young hen harrier fitted with a satellite tag on Mar Lodge Estate in 2016. Photo by Shaila Rao]
The NTS has just published an update on the return of hen harriers to Mar Lodge Estate, detailing further breeding successes in each year since (see here).
This is really, really encouraging news, but it’s only half of the story. Breeding success is meaningless if survival rates are low, and they are low, very low. The most recent national survey of hen harriers in Scotland, conducted in 2016, documented a 9% decline since the previous survey in 2010. It was the second successive decline in the Scottish hen harrier population revealed by national surveys, signalling a worrying trend. In the longer term, over a period of just 12 years, the number of breeding pairs had dropped by 27% in Scotland (see here). Illegal persecution connected to driven grouse moor management is widely acknowledged as being the most significant threat to this species’ conservation, not just in Scotland but across the UK (e.g. see here).
The NTS blog recognises this and states:
‘However, it’s not all good news. The success of hen harrier breeding at Mar Lodge Estate led to us being involved in the RSPB Hen Harrier Life Project and through this 14 harrier chicks from Mar Lodge Estate were satellite-tagged between 2016 and 2020. But of these 14 chicks, only one still survives in 2020 – a female named Tamara, who spends much of her time in Perthshire. Eight of the satellite tags stopped suddenly, with no trace of a bird or body found, raising suspicions of possible foul play‘.
Some of those young birds satellite-tagged at Mar Lodge didn’t even make it out of the Cairngorms National Park, ‘disappearing’ in suspicious circumstances on driven grouse moors – e.g. see here, here, here, here, here, joining a growing list of other sat-tagged hen harriers that have vanished or been found dead there (e.g. see here, here, here, here). Such is the extent of this issue, the Cairngorms National Park Authority has had to publish statements that illegal persecution continues to be a problem (e.g. see here).
Some of those young birds from the Mar Lodge Estate feature on the grim list of 45 hen harriers ‘missing’ or confirmed illegally killed in the UK since 2018 – see here. I’m led to believe that this list is now out of date (see here).