Bonelli’s eagles are returning to Sardinia

January 29, 2025

With support from Rewilding Europe’s European Wildlife Comeback Fund, four beautiful Bonelli’s eagles have just been released on Sardinia. Re-establishing a thriving population of these iconic birds on the Italian island will benefit nature and help turn the tide for this threatened species in Europe.

Four Bonelli’s eagles have just been released in Tepilora Natural Park on Sardinia.
GREFA

 

Towards a thriving eagle population

Four Bonelli’s eagles have just been released in northwest Sardinia, as part of a long-term programme to reintroduce these majestic yet endangered birds on the Italian island. With the support of a 49,800-euro grant from Rewilding Europe’s European Wildlife Comeback Fund, three juvenile and one adult bird were returned to the wild in mid-January, in Tepilora Natural Park. Factors such as the theft of eggs and chicks, direct persecution, and collisions with power lines meant the species had become locally extinct on the island by the 1990s, with reintroductions beginning in 2018. The grant also supported the release of four birds in 2024.

The Bonelli’s eagles are being released on Sardinia under the framework of the multi-partner, EU-funded “LIFE Abilas” initiative. The Spanish NGO GREFA, which received the comeback fund grant, was responsible for transferring the birds to the island, with releases overseen by ISPRA (the Italian Institute for Environmental Protection and Research). Three of the eagles were bred in captivity in the French Vendée region, while the fourth was provided by the Andalusian regional government in Spain.

“The reintroduction of Bonelli’s eagles in Sardinia, supported by EU funding, shows how international partners can work together to return a once extinct species to a landscape where it should be present,” say GREFA president Ernesto Álvarez. “With the overall objective of establishing a viable breeding population of the birds on the island, we are aiming to release a further six to eight eagles every year through till 2030, with the possibility of up to 10 in some years.”

 

One of the four eagles that have just been released is handled with care by a GREFA employee.
GREFA

 

An iconic keystone predator

The Bonelli’s eagle, a relatively large bird of prey often found in hilly or mountainous habitats, is emblematic of many Mediterranean regions. With an extensive Eurasian range, it can be found from Portugal in the west to Indonesia in the west. It still breeds on the Italian island of Sicily, where there are currently estimated to be around 40 mature individuals.

With a diet composed mainly of rabbits, hares, and medium-sized birds such as pigeons, the Bonelli’s eagle is considered a keystone species, helping to maintain healthy, balanced ecosystems.

“Rewilding focuses on restoring natural processes, not just on the land, but also in the skies,” explains Sophie Monsarrat, Rewilding Europe’s Rewilding Manager. “As one of the island’s few large raptors, the Bonelli’s eagles on Sardinia will play a vital role in the island’s food web and circle of life.”

 

Bonelli's eagle or Eurasian hawk-eagle, Hieraetus fasciatus or Aquila fasciata, picture taken from hide, at a feeding station for conservation purposes, utillizing live domestic pigeons caught as pests in a nearby city, Montsenis, Pre-Pyrenees, Catalonia, Spain
The Bonelli’s eagle is an iconic keystone predator, helping to maintain healthy, balanced ecosystems.
Staffan Widstrand

 

Comprehensive support measures

Factors such as habitat degradation, human-related mortality from power lines, poaching, and nest plundering mean the European Bonelli’s eagle population – of which 80% is found on the Iberian Peninsula – is currently declining. Like many diurnal raptors, the birds reach sexual maturity relatively late and lay few eggs, which makes rewilding efforts to recover populations more challenging.

On Sardinia, wide-ranging measures to support the comeback of Bonelli’s eagles include making power lines safer, securing small reservoirs and water tanks to prevent drowning, boosting wild rabbit populations, and promoting the use of non-toxic ammunition.

 

Measures to support the comeback of Bonelli’s eagles on Sardinia include efforts to boost the island’s wild rabbit population.
James Shooter

 

Journey to the wild

The four eagles that have just flown free on Sardinia followed a multi-stage release process. After spending some time in GREFA’s wildlife centre in Majadahonda near Madrid for treatment and evaluation, they were transferred to the island by staff from the Spanish NGO in November last year. They then spent a few weeks acclimatising to their new home in a purpose-built aviary.

The grant from the European Wildlife Comeback Fund was put towards expenses for captive breeding, veterinary care, the transport of the eagles, and post-release monitoring via GPS tracking and camera trapping.

 

The eagles spent a few weeks acclimatising to local conditions on Sardinia in a purpose-built aviary.
GREFA

 

Scaling up European rewilding

The European Wildlife Comeback Fund works to scale up keystone species reintroduction and population reinforcement across Europe, with an agile setup designed to support wildlife comeback in a convenient and flexible way. Thriving wildlife populations play a critical role in ensuring the health and functionality of nature – while many European wildlife species are making a comeback of their own accord, others require a helping hand in order to become re-established.

“The grant from the European Wildlife Comeback Fund, which was easily accessed, has been essential in helping us to source the Bonelli’s eagles, transport them, and release them in Sardinia,” says Ernesto Álvarez. “This exemplifies how the fund can provide invaluable assistance to organisations working to return vital wildlife species to European landscapes and seascapes.”

A separate grant of nearly 70,000 euros from the fund also supported the release of seven Bonelli’s eagles on Sardinia in 2023, through a partnership between GREFA, ISPRA, and Forestas (the Sardinian Forestry Agency).

 

The European Wildlife Comeback Fund has played a key role in the ongoing reintroduction of Bonelli’s eagles on Sardinia.
GREFA

 

Rewilding Europe invites other initiatives working to reintroduce keystone species in European landscapes to consider applying for a grant. Those interested in contributing to wildlife recovery in Europe can support wildlife comeback with an online donation. If you’d like to invest more than 50,000 euros in the European Wildlife Comeback Fund, we’d love to get in touch with you personally.

 

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