The great bustard (Otis tarda) is a charismatic and increasingly rare species of modern-day open agrarian habitats - originally it was an iconic inhabitant of the rolling Eurasian steppes. The great bustard is among the largest birds in Europe and is definitely the heaviest among those that are capable of flying. Bustards are markedly dimorphic, the males, sporting a fabulous plumage during the courtship period are much larger with their 14-16 kilograms than the 4-6-kg females that wear their camouflage colours all year round.
'Larger and stronger even than a gobbler. The head and the neck is light grey while the belly is white. The male's vivid yellow waistcoat is dappled with brown and streaked with black, the often palm-sized coverts are white and gently curved. The tail is short and is made up of wide feathers. The three-fingered legs are long and sturdy, resembling those of the flightless ratites. The beak is strong and curved. The male's moustache is of hard but finely frayed feathers. The eyes are lively and serious bespoken of distrust.'
Ottó Herman : Birds useful and birds harmful 1901
Polygamous. Competing males often cause physical injuries to each other during the end-of-winter / early spring rutting period. Following the battles, the dominant males await the females within the undisturbed rutting sites where mating takes place. Nest sites are selected by the female alone, most often within an agricultural field or grassland, at a height dependent on the amount of precipitation that year. The clutch typically consists of two eggs from which the chicks hatch after 28 days of incubation. Even though they can fly within 6 weeks, the young linger on in the vicinity of the nest site and often require the female's caretaking until the next breeding season. The first year of life is critical. According to studies carried out in Spain and Hungary, only 30% of the chicks survive to the next year. However, from the second year onwards, annual survival can reach 90%. Females reach maturity at the age of 2-4 years, while males only become sexually reproductive at 5-6 years of age. The reproductive rate is extremely low as females can only raise one chick successfully every 8-10 years.
The populations of the eastern steppes are migratory, while those living in Central and Southern Europe are partly migratory or stationary. The population inhabiting the Carpathian Basin is stationary, only moving southwards during extremely harsh winters with a lasting snow cover.
Further information about the great bustard can be found on the site Birds of Hungary (BirdLife Hungary - in Hungarian).