CURRENT DISCOVERY

The Great Bustard

• Size: up to 1 m
• Wingspan: up to 240 cm
• Weight of cockerels: up to 15 kg
• Weight of females: significantly smaller and lighter (up to 5.5 kg)
• Nest: simple hollow in the ground
• Eggs: mostly 2, rarely 3
• Breeding period: 25 - 27 days, young birds are fledged after 5 weeks,
• Age: 20 years and older; roosters reach sexual maturity at 5 - 6 years!

Great bustards eat plants such as herbs, seeds, grains, fruit and onions. Important foods in the cultivated landscape are the leaves of rape, alfalfa, clover, peas and various other arable herbs. Their diet also includes insects and small mammals. Animal food, especially grasshoppers, is particularly important for the chicks in the first two weeks of life. During this time, they are fed by their mother.
The animal proteins are particularly necessary and important for the rapid growth of the bustards. Bustards weigh approx. 90g when they hatch, by the fall they have almost reached full size.

Research results from Spain show that great bustards eat certain insects and wild plants to combat parasites and worms in their intestines. Oil beetles, for example, contain the highly toxic cantharidin, while corn poppies and viper's bugloss contain very effective alkaloids. The ingestion of these substances can prevent the transmission of diseases within bustard populations.

With the exception of the breeding season, the birds live all year round separated by sex in wide open spaces and their flight distance when disturbed is extraordinarily large. Great bustards are largely mute.

Courtship usually takes place in spring in traditional areas that have often been used for decades. It is unusual. The rival cocks turn their brown wing feathers inside out and the white elbow feathers and undersides of the wings come up. In addition, the throat pouch is inflated and the feather beard is spread.

The cocks, which are normally well camouflaged, turn into bright white balls of feathers and are visible to the hens from afar. In polygamous great bustards, several young cocks, including "onlookers", are involved in the courtship display, and the hens mate with several cocks. The breeding sites of the hens are often used repeatedly throughout their lives. Hens are very susceptible to disturbance at the start of breeding.

Great bustards live in steppe and heathland areas from Western Europe and Northwest Africa to Central and East Asia. The world population comprises almost 36,000 individuals. The largest population with more than half of the birds is found in Spain and the population numbers are declining worldwide, the species is considered endangered worldwide. Great bustards have suffered a decline of around 30% in the last 11 years. In contrast, the Central European populations have increased by 11%. Thanks to extensive conservation management in the form of the "LIFE Great Bustard (LIFE NAT/AT/000834)" project(www.grosstrappe.at) in Austria, Slovakia and Hungary, the West Pannonian bustard population living here has also recovered and has grown from under 300 to over 600 animals in the past 20 years (+ 7%). One reason for this pleasing development was, for example, the laying of approx. 150 km of high-voltage power lines under the ground in Lower Austria and Burgenland.