Great BustardOtis tardaWhere and when to see them

The great bustard is a massive bird of open grassland and traditional farmland, with a broad body, long neck and powerful wings. Males are far larger than females and rank among the heaviest living flying birds. Portugal supports an important part of the western European population, especially in open Alentejo landscapes. Agricultural intensification, infrastructure and disturbance threaten the spacious, low-intensity landscapes on which this distinctive species depends for survival.

Size

75-105 cm long

Weight

3.5-16 kg

Lifespan

Not reliably established

Status

Endangered

Outside breeding, great bustards often form flocks that walk steadily across open ground, feeding and scanning for danger. In spring, males gather at traditional display areas and transform their appearance by twisting the wings, lifting the tail and exposing white feathers. Females choose mates and subsequently incubate and rear chicks without male assistance. Birds are wary, and an apparently distant walker or vehicle can interrupt feeding or courtship. The elaborate male display involves puffing out the neck and tail feathers, creating a large white 'foam ball' like appearance to attract females. Females typically lay 2-3 eggs in a shallow scrape on the ground, camouflaged by surrounding vegetation.

• Adult males may weigh several times as much as females.
• Displaying males develop conspicuous whisker-like feathers beside the bill.
• The nest is a shallow scrape on the ground.
• Power-line collisions are a major conservation problem for this heavy flying bird.

March and April are especially useful for distant observation of spring displays in Portugal's inland plains. Cooler months can also suit flock watching. Summer heat reduces comfortable viewing time, and breeding birds remain vulnerable to disturbance even when nests are invisible. Early morning and late afternoon are generally the most productive times for observation, as birds are more active and light conditions are optimal. During the non-breeding season, large flocks can offer impressive spectacles as they forage together across fields.

Great bustards favor extensive treeless plains with a mosaic of cereal crops, fallow land, pasture and natural steppe vegetation. They need broad sightlines and relatively little disturbance. In Portugal, suitable habitat is inland rather than along ordinary coastal visitor routes. Though generally avoiding dense tree cover, they may use sparse woodland and olive groves for shelter or foraging in some areas. Conversion of steppe grasslands to intensive agriculture, along with human encroachment, poses significant threats to their remaining strongholds.

Adults eat leaves, shoots, seeds and cultivated plants, supplementing these with insects and other small animals. Chicks depend heavily on invertebrates during early growth. Diet changes through the year as rainfall, farming operations and seasonal plant development alter food availability. In addition to natural food sources, they readily consume agricultural crops like alfalfa, rapeseed, and various cereal grains, which can make them a target for farmers. Water is essential, especially for chicks, and they often seek out dew, puddles, or small water bodies when available.

Common name

Great Bustard

Scientific name

Otis tarda

Animal group

Birds

Size

75-105 cm long

Weight

3.5-16 kg

Lifespan

Not reliably established

Status

Endangered

Identification

Compared with the little bustard, the great bustard is much larger, with a heavy body, gray head and neck, and extensive white flashing across the wings in flight. Adult males are notably larger and heavier than females, weighing up to 18 kilograms, making them one of the world's heaviest flying birds. During display, males develop distinct 'whiskers' formed by elongated feathers on either side of the bill, a key feature for identifying displaying individuals.