The great bustard (Otis tarda ) is a bird in the bustard family, the only member of the genus Otis. It breeds in open grasslands and farmland from northern Morocco, South and Central Europe, to temperate Central and East Asia. European populations are mainly resident, but Asian populations migrate farther south in winter. It has been listed as Vulnerable on the IUCN Red List since 1996.
Portugal and Spain now have about 60% of the world's population. It became extinct in Great Britain when the last bird was shot in 1832. Recent attempts to reintroduce it into England have met with some success and there is a population of 40 birds on Salisbury Plain, a British Army training area. Here the lack of public access allows them the freedom needed as a large ground-nesting bird.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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OmnivoreAn omnivore is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and ani...
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example, foliage, for the main component of its die...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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PrecocialPrecocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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PolygamyPolygamy is the practice of breeding with multiple partners. When a male breeds with more than one female at the same time – it is called polygyny....
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FlockingFlocking birds are those that tend to gather to forage or travel collectively. Avian flocks are typically associated with migration. Flocking also ...
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MigratingAnimal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migrati...
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Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withThe Great bustard is a member of the bustard family and the only member in the genus Otis. One of the heaviest birds alive today that can fly, it is found across Europe. Huge, robust but stately looking, adult males have a bulging neck and a heavy chest, with a characteristically cocked tail. The breeding plumage of males includes white moustachial whiskers that are 20cm long, and their back and tail become more vividly colored. They develop a band of feathers on their breast and lower neck that are russet colored, becoming brighter and wider as they get older. These birds walk with an upright stance, and fly with powerful and regular wing beats.
Great bustards are endemic to central and southern Europe, where they are the largest bird species, and across temperate Asia. In Europe, populations are mainly resident, while Asian birds travel further south in winter. This species inhabits grassland, steppe, and open, agricultural land. They favor regions for breeding with little or no presence by humans.
These birds are diurnal, and, among vertebrates, have one of the greatest differences in size between the sexes. For this reason, males and females live in separate groups for almost the whole year, except during the mating season. This size difference also affects food requirements as well as breeding, dispersal and migratory behaviors. Females tend to flock together with individuals who are related. They are more philopatric and gregarious than males, and will often remain at their natal area for their entire life. In winter, males establish a group hierarchy, engaging in violent, prolonged fights, stabbing the head and neck of other males, sometimes causing serious injury, behavior which is typical of bustards. Some populations of Great bustards are migratory, gathering at pre-migratory sites in great numbers in order to collectively move to winter grounds.
The Great bustard is omnivorous, it eats vegetation such as grass, legumes, crucifers, grains, flowers and grapes. It also eats rodents, the chicks of other species, earthworms, butterflies, large insects and larvae. Lizards and amphibians are also eaten, depending on the season.
These birds are polygynous, and one male may mate with as many as five females. The males perform spectacular courtship displays, competing in a lekking system, where they gather at a ‘lek’ or small display ground to try to impress the females. The breeding season is in March, and eggs are laid in May-June, depending on the region. Nests are usually close to leks. 2-3 eggs are laid and the female on her own incubates them for about 25 days to a month. Chicks are precocial and can immediately leave the nest. Their mother raises them and they fledge at around 30-35 days. They do not reach full size until 80 to 120 days old, and for about ten months are dependent on their mother.
This species suffers from the fragmentation and loss of its habitat. Increasing land privatization and human disturbance is expected to cause more habitat loss with the plowing of grasslands, afforestation, intensive agriculture, increased use of irrigation schemes, and construction of power lines, roads, fencing and ditches. Chemical fertilizers and pesticides, mechanization, fire and predation are major threats for the chicks and juveniles, while hunting of adult birds causes high mortality in some countries where they live.
According to the IUCN Red List, the total population size of the Great bustard is around 44,000-57,000 individuals. Currently this species is classified as Vulnerable (VU) and its numbers today are decreasing.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...