Bonelli Eagle Observation

Bonelli's eagle is the emblem of the Serra de São Mamede, and watching it hunt over the granite cliffs is one of the finest wildlife experiences in the Alentejo. The Serra de São Mamede is a compact mountain range in the north-east of the region, near the Spanish border, rising to 1,025 metres, and it is protected as a natural park. Its mixture of crags, oak and chestnut woods, scrub and open farmland provides the habitat that this elegant bird of prey needs, and it is one of the places in Portugal where the species still breeds.

The eagle is a medium-large raptor, powerful and fast, with a long tail and broad wings. Adults are dark brown on the upperparts with a pale, streaked underside and a distinctive white patch on the back, and a dark band along the end of the tail. Juvenile birds are more rufous below and take several years to reach adult plumage. Bonelli's eagles typically hunt rabbits, partridges and pigeons, often working in pairs, and they perform spectacular dives. They nest on cliff ledges, which makes them vulnerable to disturbance, and their numbers have declined across southern Europe because of habitat loss, electrocution on power lines and persecution. In Portugal, the species is considered threatened, and the surviving pairs depend on protected areas such as this one.

The São Mamede has other raptors that can be seen on the same outing. Griffon vultures roost and nest on the cliffs, and Egyptian vultures, golden eagles, black storks and a variety of smaller birds of prey also live in the range. A well-known spot for watching vultures is the crag at Fraga da Espardeira, near Marvão, where birds soar on the thermals along the rock face. Marvão itself, perched on its granite crest, is a base from which many birdwatchers work, and its castle walls give wide views over the sky and the valleys.

Watching eagles requires patience and care. Use binoculars or a telescope, sit still and scan the ridges and the sky, especially in the morning and late afternoon, when the birds are most active. Keep your distance from nesting areas, avoid playing recordings and never approach nests, particularly in the breeding season from late winter to early summer. Stay on public paths and viewpoints, and follow advice from the park authorities. Local guides and nature tourism companies can lead trips to good spots and ensure that the birds are not disturbed, and they know where and when sightings are likely.

The best seasons for birdwatching in the park are spring and autumn, when the weather is mild and migrants pass through, though the eagles can be seen all year. Take layers, water and food, as services are limited. The activity suits nature lovers and photographers who are willing to wait.