Great Bustard
Otis tarda
Great Bustard: One of the Heaviest Birds That Can Still Fly
The great bustard (Otis tarda) is a big, goose-shaped bird of open grassland and farmland from Spain and Morocco to Mongolia and China. Males are among the heaviest flying birds on Earth, a title they share with the kori bustard, and the species is now listed as Endangered.
- Habitat
- Open steppe, grassland and low-intensity farmland
- Size
- Males 90–115 cm tall, 5.8–18 kg; females 3.5–5 kg
- Wingspan
- Males 2.1–2.5 m; females 1.7–1.9 m
- Diet
- Shoots, leaves, seeds, insects, small vertebrates
- Range
- Iberia and Morocco to Mongolia and China
- Conservation
- Endangered (IUCN, 2023)
Habitat & range
Great bustards live in open, flat or gently rolling country: natural steppe and grassland, and low-intensity farmland with cereals, fallow fields, pasture and fodder crops such as alfalfa. They avoid busy, heavily disturbed fields near towns (Great Bustard Group; BirdLife International). The breeding range runs from Portugal, Spain and Morocco through central and eastern Europe, Turkey, Russia and Kazakhstan to Mongolia and northeast China, but it has become patchy. Spain alone holds about 74% of the world population. Iberian and central European birds move only short distances, while the eastern subspecies in Mongolia, Russia and China is fully migratory (BirdLife International).
Size & appearance
The great bustard is one of the heaviest flying birds on Earth, a title it shares with Africa's kori bustard. Mature males weigh 5.8 to 18 kg, and the heaviest verified bird, collected in Manchuria, weighed about 21 kg. Females weigh only 3.5 to 5 kg. Males can be up to five times heavier than females, the largest size difference between the sexes of any bird. Males stand 90 to 115 cm tall with a wingspan of 210 to 250 cm (Great Bustard Group). It is shaped like a large goose with longer legs and a straighter neck. Breeding males have a grey head and neck, white whisker-like plumes about 20 cm long, and a russet band across the lower neck and breast that grows wider with age. The back is buff with black barring, and the underparts are white. Females are smaller and more camouflaged. Bustards have only three forward-facing toes and no hind toe, so they can run fast but cannot perch (Great Bustard Group).
Diet & behaviour
Great bustards are omnivores. Adults eat mostly shoots, leaves, flowers and seeds, plus insects, worms, small lizards and even voles or mice. Chicks eat mainly insects at first (Great Bustard Group). In Spain, a 2014 study found that males pick out toxic blister beetles, which contain cantharidin, and eat more and larger ones than females. The researchers suggest it may be a form of self-medication against parasites and gut bacteria (Bravo et al. 2014, PLOS ONE). Outside the breeding season they live in single-sex flocks called droves. They walk slowly but can run at about 48 km/h (30 mph) and fly at up to about 80 km/h (50 mph), usually 30 to 100 m above the ground (Great Bustard Group).
Breeding
Males display at traditional leks. A displaying male pulls his head back, inflates a balloon-like throat pouch, and turns his wings and tail inside out into a mass of white feathers, a pose called the foam bath. The white feathers reflect ultraviolet light and can be seen from several kilometres away. One male may mate with up to five females (Great Bustard Group). The nest is a bare scrape in tall grass or crops, usually with 2 or 3 eggs of about 150 g. The chicks can leave the nest when about a day old, and the female raises them alone. Wild birds may live up to 20 years (Great Bustard Group).
Conservation
BirdLife International moved the great bustard from Vulnerable to Endangered on the IUCN Red List in 2023. There are an estimated 29,600 to 33,000 mature birds, and numbers are falling. The main threats are farming intensification, ploughing of grassland, collisions with power lines and wind turbines, illegal hunting, pesticides and predation of nests and chicks. Marking or burying power lines and bird-friendly farming schemes help, and the population in Germany, Austria and Hungary has grown with intensive conservation work (BirdLife International). Great bustards died out in Britain in the 1830s; the last one was shot in 1832. A reintroduction project in southern England began in 2003 and has built up a population of around 100 birds (Great Bustard Group; BirdLife International).
Fun facts about Great Bustard
- The name bustard comes from the Latin avis tarda, meaning slow bird, after its deliberate walk (Great Bustard Group).
- A group of great bustards is called a drove and can hold 20 to 40 birds (Great Bustard Group).
- A great bustard appears on the flag of Wiltshire in England (Great Bustard Group).
- Chicks start whistling from inside the egg before they hatch (Great Bustard Group).
Great Bustard vs Honey Badger
The bustard's size and its escape into the air beat the bold but much smaller honey badger.
This is a fun who-would-win pairing rather than a recorded encounter. Picture a fearless honey badger rushing at a great bustard feeding on open grassland, aiming for the bird's legs. A big male bustard stands up to about 115 cm tall and can weigh up to 18 kg (Great Bustard Group). It spreads its huge wings, backs away and runs, and with a few powerful wingbeats it is off the ground and out of reach, flying at up to about 80 km/h (50 mph) (Great Bustard Group). The badger is left with nothing to bite, so the round goes to the bustard.
Read more about Honey Badger.
Common questions about Great Bustard
Can a great bustard actually fly?
Yes. It is believed to be the heaviest flying bird on Earth, with big males up to 18 kg. It usually flies 30–100 m above the ground at up to about 80 km/h, but with only three forward toes it can't perch in trees (Great Bustard Group). See where it ranks in our largest birds in the world showdown.
How much bigger are male great bustards than females?
Much bigger. Mature males weigh 5.8–18 kg, while females weigh just 3.5–5 kg, so a male can be up to five times as heavy. That is the largest size gap between the sexes of any bird (Great Bustard Group).
Why do great bustards eat poisonous blister beetles?
Possibly as medicine. A study in Spain found that male great bustards pick out blister beetles, which contain the toxin cantharidin, and eat more and larger ones than females. Cantharidin kills some gut bacteria and worms, so the authors suggest males self-medicate to look healthier to choosy females (Bravo et al. 2014, PLOS ONE).
Is the great bustard endangered?
Yes. It was moved from Vulnerable to Endangered on the IUCN Red List in 2023. About 29,600–33,000 mature birds remain and numbers are falling, mainly because of farming intensification, power-line collisions and illegal hunting. Around 74% of them live in Spain (BirdLife International).
Are there great bustards in the UK again?
Yes, a small population. Great bustards died out in Britain in the 1830s, and the last one was shot in 1832. A reintroduction in southern England began in 2003 with birds and eggs from Russia and later Spain, and it now has around 100 birds (Great Bustard Group; BirdLife International).
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