Bonelli's Eagle: where and when to see them

Bonelli's eagle is a powerful, agile raptor of warm, broken landscapes, including Mediterranean cliffs and scrub-covered hills. Adults contrast dark upperparts with pale, streaked underparts and a broad dark tail band. Although globally assessed as Least Concern, it is scarce and conservation-sensitive in parts of Europe. Productive territories need both secure nesting places and open hunting habitat, while electrocution, collisions, persecution and disturbance can undermine otherwise suitable landscapes.

Size

55–65 cm long; 145–165 cm wingspan

Weight

1.5–2.5 kg

Lifespan

Not reliably established

Status

Least Concern

Territorial pairs often remain together throughout the year, maintaining large home ranges around traditional nesting areas. They hunt from perches, by low searching flight or through fast aerial pursuit, and may cooperate when attacking prey. Courtship can include conspicuous aerial displays. Nests are substantial stick structures, usually on cliffs in Mediterranean settings, and repeated human presence near an active nest can disrupt breeding even when the adults initially remain visible. Courtship flights often involve spectacular undulations and talon-grappling between partners, usually occurring near the nest site. They are known for their powerful, direct flight, often soaring purposefully with relatively stiff wings, different from the more buoyant soaring of some other eagles.

• The name honours Italian naturalist Franco Andrea Bonelli.
• Pairs sometimes hunt cooperatively.
• Young birds have warmer, more rufous underparts than adults.
• A territory may contain several alternative nests used in different years.

Resident pairs may be present year-round in Greece. Spring and autumn can offer comfortable scanning conditions, while breeding-season disturbance requires particular restraint. Warm rising air may encourage soaring later in the morning, but territorial birds can remain out of view for long periods. The post-breeding dispersal of young birds in late summer and early autumn can sometimes lead to sightings in less typical areas. Early mornings, when the air is still cool, can also be productive for observing birds leaving their roosts to begin hunting.

Rocky hills, gorges and coastal cliffs adjoining scrub, open woodland and low-intensity farmland provide suitable habitat. Nest sites need relative security from disturbance. In Greece, much potential territory lies inland or above rugged coasts rather than beside easily accessible waterfront paths. While specific habitat features are crucial, their strong fidelity to nesting sites means they often remain in territories even if some habitat quality degrades. They are generally found at lower to mid-altitudes, avoiding the highest mountain ranges where other large raptors might dominate.

Medium-sized birds and mammals are important prey, particularly pigeons, partridges and rabbits where available. Reptiles also contribute in some areas. Diet changes with local prey communities, and the eagle's manoeuvrability allows it to capture both ground-dwelling animals and birds in flight. Their diet frequently includes substantial numbers of rock doves and chukar partridge in many Greek locations. Juveniles and less experienced hunters may target smaller, easier prey items like small birds or lizards more frequently.

Common name

Bonelli's Eagle

Scientific name

Aquila fasciata

Animal group

Birds

Size

55–65 cm long; 145–165 cm wingspan

Weight

1.5–2.5 kg

Lifespan

Not reliably established

Status

Least Concern

Identification

Adults show a pale back patch, streaked white underparts and a broad dark terminal tail band, unlike the more uniformly dark adult golden eagle. In flight, the adult Bonelli's Eagle displays distinct white underwing coverts contrasting with dark flight feathers, particularly prominent on the carpal joint. Juveniles are more uniformly rufous below, lacking the adult's streaked white underparts and often show a less defined tail band.