Living with the Bonelli's eagle, an endangered species

The Bonelli's Eagle, a large bird of prey typically found in Mediterranean regions, has become increasingly rare over the twentieth century. Today, this species is of particular concern to nature preservation associations and is the subject of a national action plan that aims to eliminate the causes of its decline.


Bonelli's eagle © Regard du Vivant


  • Project partner:  Languedoc-Roussillon nature conservatory, technical coordinator of the national action plan,
  • Country:  France
  • Project type: Preservation of the environment
  • Budget: €12,500 from 2008 to 2011

The Foundation works alongside those who protect the mountains' large birds of prey. Our vocation is to help to improve dialogue between naturalists and those who enjoy leisure activities in open outdoor areas, which is why we support the Languedoc-Roussillon conservatory of natural areas, coordinator of the action plan, in its efforts to protect this endangered species.

Increase awareness to protect the Bonelli's eagle

Interview with the Languedoc-Roussillon conservatory of natural areas (CEN LR)

How to identify a Bonelli's eagle?

The Bonelli's eagle is slightly smaller than a Golden eagle. In flight, it is easy to distinguish because of the contrast between its dark wings and its white body with distinctive brown streaks. This eagle has a relatively long life expectancy, living up to 30 years in natural environments.

Bonelli's eagle © Regard du vivant Bonelli's eagle © Regard du vivant

Where is it found?

The Bonelli's eagle is found along the Mediterranean coast, from the Iberian Peninsula to Iran, as well as on the Indian sub-continent and in southern China and Indonesia. Today, its total population is estimated at fewer than 40,000 pairs. Approximately 1,000 pairs live in Europe, with Spain remaining something of a stronghold for the species, counting almost 700 pairs. In France, there were just 29 reproducing pairs in 2009, which is very few and makes it the country's most threatened species.

Distribution of the Bonelli's eagle in the world

Where does it live? Does it remain in the same area?

This eagle typically favors Mediterranean environments. In France, it mainly nests on low altitude cliffs, on ledges or in caves. Its hunting ground consists of open lands, where prey is plentiful. Adults remain attached to their territory, often for life and pairs generally stay in their chosen place of reproduction.

couple of Bonelli's eagles © Regard du vivant Bonelli's eagle on a cliff © Regard du vivant

What are the particular threats it faces?

The main threats to this population are:

  • persecution - by shooting, trapping, poisoning - which represents the main threat to the survival of the species because it affects the adult birds.
  • electrocution: its huge wingspan means that when an eagle lands on the metal structure of a medium voltage electricity pylon, its wings can touch the cables, resulting in electrocution.
  • disturbance due to outdoor activities such as rock climbing, hiking, free flight, mechanical sports, etc. Although these activities do not kill the adult birds, they can disturb them to the point of causing them to abandon their nests and young.
  • There are of course other threats like trichomonose disease, destruction of habitat, landscape alterations, etc.

Bonelli's eagle - flight © M.Mure

What is the protective status of the Bonelli's eagle?

In France, like all birds of prey, the Bonelli's eagle is a protected species. In the European Union, it is mentioned in the Birds Directive for the conservation of wild birds. On an international level, the species is listed in the "endangered" category on the IUCN red list because of the high risk of its extinction in nature.

National Action Plans: previously known as "national restoration plans", these plans formulate state policy related to the conservation of species, thereby complying with the national strategy for biodiversity that resulted from the Rio convention in 1992. Each plan is specific to a single species whose conservation status is endangered. They combine scientific studies and conservation actions to focus on three themes: knowledge, conservation and awareness.

Bonelli's eagle back © Frédéric Larrey / Thomas Roger

How does the Petzl Foundation help you?

The Petzl Foundation supports us in our awareness actions aimed at outdoor nature sport enthusiasts, particularly with instruction and equipment professionals. Our goal is to protect the future nesting sites to allow the species to develop.

The Petzl Foundation also contributed to a travelling exhibition about the Bonelli's eagle, produced by the Regard du Vivant association. This exhibition was presented at a number of rock climbing schools, clubs, conferences and festivals.

Question for Alain Ravayrol, rock climber and member of the Bonelli's eagle banding team in Languedoc-Roussillon

How would you describe relations between the Bonelli's eagle and rock climbers?

Bonelli's eagle © Stéphane Lozac'hmeur
Alain Ravarol with a chick, before banding

Awareness of the issue and measurement of the decline of the Bonelli's eagle population date back to the early 80s. At the time, almost all birds of prey were considered vulnerable: eagles, vultures, Peregrine falcons, Eurasian eagle owls, etc. These concerns coincided with a huge increase in interest for outdoor leisure pursuits, particularly rock climbing.
In Languedoc-Roussillon, all the sites occupied at the end of the 90s are now subject to protective measures (biotope protection orders), which prohibit the equipping of rock faces or set limits for extending such equipment wherever extension is a possibility. This was also a period of conflict between naturalists and climbers, varying in its openness and virulence, centered on the issue of developing sites for rock climbing.

In 1980, to face up to the preservation issue, climbers asked for a list to be drawn up of sites not to be equipped. However, conservationists were unable to meet this demand for two main reasons:

  • the publicity surrounding listed sites can lead to other problems;
  • these birds do not necessarily stay in the same sites definitively, therefore such a list would not be reliable in the long run.

The naturalists, who wanted all rock climbing site projects to be subject to an upstream review found themselves up against climbers who usually preferred to take over new sites more or less discreetly.
A vicious circle of conflict developed between ornithologists, seen as banning fanatics and climbers, held to be responsible for the decline of one of the symbolic elements of Mediterranean biodiversity: the reproduction sites of the Bonelli's eagle.

A number of dialogue initiatives subsequently revealed that contact between climbers and nature protectors could be rich in terms of exchange and that cohabitation was therefore possible.
Increased awareness of the deterioration of our environment and recognition of the knowledge and experience of all involved helped the situation to evolve on both sides. Today, a case by case analysis on the scale of a mountain range appears to be the most relevant type of action.

Banding the Bonelli's eagle in Languedoc-Roussillon
Banding the Bonelli's eagle in Languedoc-Roussillon

When were leg bands first used for the Bonelli's eagle?

The Bonelli's eagle banding program, validated by the natural history museum in 1990, has been running for almost 20 years. Every year, almost all the young birds born in France are banded. Along with monitoring the reproductivity of each pair, banding is the principal tool for demographic studies which will only be useful in the long term.

How do you go about banding?

When the baby eagles reach the age of 35-45 days, they are "collected" from the eyrie and the bands are then applied at either the top or bottom of the rock face. This operation only takes a few minutes: the birds are weighed, their biometric measurements are recorded, a few sample feathers are taken and a metal or plastic leg band is applied. They are then immediately returned to their nests.

Banding the baby eagle © Stéphane Lozac'hmeur Banding the baby eagle- zoom © Stéphane Lozac'hmeur
A color coding system for better remote visual identification

How do the parents react?

Contrary to popular opinion, they do not attack us. The adults are often away from the site, and even if they can see the nest, they stay away. They sometimes return to the nest, with or without food, as soon as we leave.
This single annual visit has always been without major incident for both the juvenile birds and the climbers involved. However, it has enabled us to identify a number of reasons for the failure of reproduction during the nesting period in the eyrie. It has also helped us to understand what disturbs roosting birds.

GPS monitoring to help protect this endangered species

To be able to monitor the movements of birds of prey and to get a better grasp of their vital domain, a new technology was developed in 2011. A telemetric prototype, weighing less than 60g, was developed by engineers at the CEA's LETI lab in Grenoble.

a Bonelli's eagle with the prototype
The prototype is tested on an eagle

The tag was tested on a domestic vulture and the results were encouraging. In autumn 2012, after a further development and test phase,Bonelli's eagles have been tagged.

The technology may then be used for preservation actions on other species, as well.
For more information:

Photo: Regard du vivant and Stéphane Lozac’hmeur.

Updated in september 2014



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