Two young white-tailed eagles found dead from poisoning in Co Antrim were part of an Irish Government reintroduction programme.
Police in Northern Ireland are investigating the wildlife crime and a £5,000 reward has been offered to anyone with information that leads to a conviction.
A post mortem and toxicology tests found the birds had insecticide bendiocarb in their system.
Remains of the priority species were discovered near Glenhead Road, Ballymena on May, 15.
One had been released on the lower River Shannon in August 2022 by then Taoiseach Micheál Martin as part of the NPWS white-tailed Eagle reintroduction programme.
Its tags showed it crossed into Northern Ireland from Donegal on May 1 and was found dead just two weeks later.
NPWS believe the second bird likely fledged from a nest in Munster in 2021.
Minister of State for Heritage and Electoral Reform, Malcolm Noonan, said: “I am appalled at what appears to be a poisoning incident that has led to the death of two white-tailed eagles.
“It has been encouraging in recent years to see birds nesting and rearing young hatched eagles here for the first time in over 100 years.
“An incident like this sets back our ambition but we won’t be deterred.
“Whatever misunderstanding that is out there needs to be challenged. Toxic substances such as carbofurans are banned and need to be handed over for safe disposal.
“NPWS will work with colleagues in Northern Ireland, An Garda Siochana and the PSNI to fully investigate this incident and hopefully secure a successful prosecution.
“Wildlife crime is wrong at any time but in a time of a biodiversity crisis it is socially abhorrent and I would urge anyone with information relating to this incident, to speak to the PSNI.”
The priority species was persecuted to extinction across Ireland in the 1900s.
But some 100 young white-tailed eagles were reintroduced at Killarney National Park as part of an Irish Government programme to return the species to the island from 2007-2011.
A second phase was then announced from 2020-2022 but some have fallen victim to bird flu, illegal poisoning and extreme weather.
Director General of the NPWS Niall Ó ’Donnchú added: “White-tailed eagles are beautiful and rare birds, and while we are in the midst of a successful reintroduction programme, these setbacks truly matter.
“The deliberate poisoning of birds of prey is a heinous crime against nature and an offence under the Wildlife Acts. These birds have no means of detecting that they have been baited and the malice of forethought in these acts doesn’t bear thinking about.”
How the birds came into contact with bendiocarb remains part of an ongoing investigation, and the PSNI says it is committed to working with partners and members of the public to determine how the birds consumed the toxic insecticide.
Rural and Wildlife Crime Superintendent, Johnston McDowell, said: “The test results suggest an individual not only has access to the insecticide bendiocarb but has placed this into the outside environment illegally, so wild birds have been able to consume it.
“Bendiocarb is present in the trade product Ficam D, a powder which is only permitted for indoor use to control crawling insects such as wasps and ants, so using this active ingredient in fields would be a breach of Biocidal Products Regulation.
“The illegal killing of these beautiful birds in a popular rural area is disgraceful, and for any individual to think they can ignore the law and lay poisonous bait which has led to the killing of these birds, is unacceptable and will not be tolerated.
“There must be people in the community who are aware of individuals committing these offences, and who can come forward and assist police with any information they have.”
The RSPB is offering a £5,000 reward for information.
RSPB NI Investigations Officer, Dean Jones, said: “Poison left out in the open like this is utterly indiscriminate and poses a huge risk not only to wildlife but to people and pets.
“It is not only illegal, but extremely irresponsible and dangerous. We implore that anyone who knows any information on who is responsible for the death of these birds to get in touch with the PSNI.”
