Death of White-tailed Eagle G461

One of the most pleasing aspects of the first three years of the White-tailed Eagle project has been the great excitement of people who have seen one of the birds. The far-ranging exploratory flights of the young eagles has meant that they have been enjoyed by birders and wildlife enthusiasts across much of the UK. People often ask us to give the eagles’ daily locations on the website but we need to prevent disturbance to the eagles and local people. We have made many friends in the farming, forestry and landowner communities who have welcomed the great birds on their land.

Encouragingly, we are now seeing some of the older birds – those released in 2019 and 2020 – returning to the Isle of Wight and the wider South Coast region where we hope an initial breeding population will become established. On the Isle of Wight two eagles released in 2019, G274 and G324 have paired up, and, although still too young to breed, they are showing territorial behaviour. Meanwhile two of the 2020 cohort – male G471 who recently returned to the South Coast after an extended stay in southern Scotland, and female G405, who spent much of last year in South West England – are showing the first signs of forming a second pair, and have spent much of the past week in the South Downs in West Sussex, which is another potential breeding area.

Another bird that returned to the South Coast after spending a prolonged period away was G461. This male eagle, released on the Isle of Wight in 2020, explored widely along the South Coast during spring 2021 and then spent much of last summer in West Norfolk. After returning south in September, and being chased away from the Isle of Wight by G274, the young male began favouring Poole Harbour in Dorset. This huge natural harbour, with its abundant populations of a favoured prey species, the Grey Mullet, is a likely breeding site for White-tailed Eagles in the future.

G461 at Poole Harbour in October 2021 (photo by Mark Wright)

G461 spent much of the autumn and early winter at Poole Harbour where many excited birdwatchers and members of the public were able to enjoy watching it.  On one occasion a boat full of school children enjoyed a fly past during a trip organised by the local charity Birds of Poole Harbour.

When not at Poole Harbour, G461 also visited the nearby Purbeck coastline, and spent time in North Dorset, in an area that has been visited by several other White-tailed Eagles since the project began.

G461’s movements after release on the Isle of Wight in 2020

Sadly, in late January the data from G461’s satellite tag gave us cause for concern, and we subsequently recovered the bird’s body in North Dorset on 27th January, with Dorset Police and members of the RSPB Investigations team.

Post mortem and toxicology testing through the Wildlife Incident Investigation Scheme has subsequently identified brodifacoum poisoning as the cause of death. Brodifacoum is a highly toxic anticoagulant rodenticide that causes internal haemorrhaging. The bird’s liver contained approximately seven times the amount of brodifacoum required to kill a bird like a White-tailed Eagle. The satellite data indicates that the eagle, which was otherwise healthy, deteriorated and died over a period of several days.

Dorset police have today made a statement that no further police action will be taken.

Recent evidence indicates that brodifacoum poses a serious threat to birds of prey. It accumulates in the food chain and can cause secondary poisoning as a result. A number of cases where dead raptors have been found with very high levels of brodifacoum have suggested that it could also be illegally misused in some instances to target birds of prey. White-tailed Eagles are particularly at risk because carrion can form a significant part of the diet, especially of birds in their first year.  EU Environmental Risk Assessments have previously concluded that second generation anticoagulant rodenticides (SGARs) such as brodifacoum should not be permitted for external use because the environmental risk is too great. However, regulations around their use in outdoor settings in the UK have been relaxed in recent years, and we believe this could pose a significant risk to birds of prey and other wildlife.

It is very disappointing that G461 has become the latest bird of prey to die of brodifacoum poisoning, and we hope that the death of this bird serves as a reminder of the toxicity of anticoagulant rodenticide poisons and the impacts they can have on wider wildlife.

More encouragingly, two female White-tailed Eagles, G318 and G801 are the latest birds to take up residence at Poole Harbour, and there have been numerous sightings in recent weeks. With G463 back in England after spending five months in continental Europe last year, we are hopeful that the young male may eventually join the birds at Poole Harbour, particularly as G318, released in 2019, is now approaching breeding age. Since arriving back in England last November G463 has spent much of its time in East Anglia, but also returned to Chard area in Somerset – where it had spent its first winter – and visited Knepp in East Sussex last week.

Despite the loss of G461 we very much hope that White-tailed Eagles will become an increasingly familiar sight at Poole Harbour and in other parts of southern England, and that many more people will be able to enjoy seeing them in years to come.

G461 perched on the Brownsea Lagoon, with Poole in the background (photo by Alison Copland)