Great bustard
Great bustard Otis tarda Castilian: Avutarda común Catalan: Pioc salvatge Gallego: Avetarda Euskera: Basoilo handia CLASIFICACIÓN: Orden: Gruiformes Family: Otididae Migratory status: Permanent resident CONSERVATION STATUS: On the National List of Threatened Species, it appears in the “Of Special Interest” category. In the 2004 edition of the Red Book of Spanish Birds (Libro Rojo de las Aves de España) it is listed as “Vulnerable”.
Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser. listen song THREATS The loss of habitat due to agricultural intensification and the proliferation of infrastructure and urbanised areas reduce this species' food supply and therefore its reproductive capacity. Electrical cables, illegal hunting (which especially targets males), human disturbances and accidents with fences are other problems. |
Length / size: 75-105 cm / 190-260 cm Identification: A very robust and heavy bird (males can weigh up to 18kg). Both sexes have a grey head and neck, a white belly, and their back and wings are brown with horizontal bars; their wings also have a characteristic wide white band that can be observed in flight and contrasts with their black flight feathers. Females are smaller and duller in colour. The two sexes also differ during mating season: males develop “whiskers”, rigid and pointy feathers that come out of the lower mandible; their neck becomes thicker and takes on a deep reddish colour. Song: Silent, although during mating season the males make different sounds. Diet: It feeds on plant matter and invertebrates, depending on the season: in spring and summer it consumes insects and other invertebrates together with seeds and shoots; in winter it particularly eats leguminous plants. Reproduction: Year after year the birds come together in the same leks, which are open areas used for the performance of "the rounds", spectacular mating displays. After copulation, the males participation in breeding ends. The female builds the nest on the ground in a small depression that is sheltered by a patch of grass. Shortly after hatching, the chicks have cryptic down and are able to feed themselves and move about together with the mother. Juvenile dispersion occurs in males, which establish themselves in places different from where they were born, while the females remain in the surrounding areas. HABITAT It occupies open, flat spaces which are used for non-irrigated grain farming, or fallow land or pastureland. DISTRIBUTION In Spain: It is widely distributed in both Plateaus and in Extremadura. In Castile and León: It breeds in all the provinces except Soria. Movements and migrations: A part of the population makes movements related to age and sex: females are more mobile, while males move from their breeding areas to their summering areas, and from those to their wintering areas. POPULATION In Spain: There is an estimated population of 24000-26000 breeding individuals. In Castile and León: There is an estimated population of 10000 breeding specimens (1998 data). | |