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24 November 2024
Thistle (H03) - Attacked by Eagle
It is with great sadness that we need to report that Thistle H03, named by Scouting Scotland, has died after attack by another golden eagle or eagles. Thistle was sadly found dead in June and a series of tests were carried out as part of a postmortem.
The postmortem detected puncture wounds matching eagle talons and a transverse fracture of the skull just behind the beak, between the eyes.
Left: Thistle shortly after release: July 2022.
Two additional puncture wounds were detected in the left side of the head and a single puncture wound at the bottom of the sternum on the right side of the breast bone. Every dead eagle found undergoes a full post mortem including X-ray, CT scan, HPAI test and toxicology to detect or rule out other causes of death. Thistle was otherwise in very good condition.
The post mortem confirmed ‘trauma: eagle attack’ as cause of death.
Thistle, a two year old male, was collected from a nest on RSPB Abernethy estate in the highlands on the 9th June 2022. Thistle was released at the end of July that year and remained at the release site for several weeks before leaving to hunt for himself.
To read more about Thistle, click the link below:
Meet Thistle | Blog | South of Scotland Golden Eagle Project
Right: Thistle and sibling at eyrie during collection
Golden eagles typically explore widely for 3-5 years before settling on territory. Thistle was in this wandering phase when he died. Satellite tag data shows that shortly before death Thistle was hunting close to an established eagle nest with large young on the verge of fledging. Often, adult eagles will tolerate younger birds outwith the breeding season but when feeding and fledging young they can become much more aggressive, defending their territory from other eagles.
The breeding female from that local nest is also satellite tagged. Roxy, a 14 year old female, fledged from a nest in Galloway and has been breeding in the Scottish Borders for several years. We can’t say with certainty what happened but we can make an educated guess from the data we have. We know that Thistle was hunting within the territory of Roxy and her mate shortly before death. Thistle was fairly close to the nest and was likely spotted by Roxy and her mate and chased.
It is likely that Thistle was attacked in the air and fatally wounded. Thistle’s body was found at the base of a Sitka spruce tree on the edge of the moor where he was hunting. Presumably Thistle then dived down into a gap in the Sitka plantation to hide. There were several small branches on and around Thistle’s body suggesting that he possibly fell to the ground and died very shortly after.
The data from the breeding female, Roxy, showed that she roosted in the Sitka plantation close to Thistle’s body on the night he died, presumably keeping an eye on the area to ensure the intruder was not coming back.
While it is very sad to lose Thistle, this is a natural cause of death and part of normal eagle behaviour. Roxy and her mate were simply defending their young and Thistle was in the wrong place at the wrong time.
Many thanks to the Game Keepers from the local estate who assisted the team in recovering the body of Thistle.
Above: Thistle (on perch) shortly after release.
Recovery of Thistle’s body highlights the value of satellite tagging. Without this valuable technology we would not have found this eagle and known its cause of death.
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