I always find it impressive when I see really really ridiculously big birds flying. It just doesn’t seem like they should be able to lift themselves off the ground. So today I’m going to honour big birds by writing about the heaviest flying bird in the world, the great bustard.

Great bustards live in Europe and Asia, with the biggest populations in Portugal and Spain. The birds that live in Europe usually stay there all year, but the the Asian population is migratory, as it gets pretty cold in Asia. The great bustard lives in grassy areas that are flat and poorly treed. Agricultural fields make good habitats for bustards, though they don’t like people and tend to avoid interactions with humans, especially during the breeding season.

See they really can fly!
Image by Nicolas Weghaupt, CC0, via Wikimedia Commons

As I mentioned, the great bustard is pretty big. More accurately, the male bustards are super big. The great bustard is one of the most sexually dimorphic birds in the world, in terms of weight difference between males and females. Males can weigh up to 21 kg, with a 2.7m wingspan. Females, on the other hand, reach a paltry 8 kg. As far as colours go, the bustard is pretty bland. Both sexes are a mix of brown, black and white. Males have some decoration in the form of neck bristles that grow throughout the birds’ lives, reaching up to 15 cm in length. But overall these birds aren’t all that flashy.

Male and female bustards don’t like to be alone, but they also don’t really like members of the other sex. Both sexes tend to form groups that stay separate from the opposite sex until the breeding season. This occurs in March, though males start thinking about breeding much earlier. During the winter, males compete for dominance, using their bills to whack each other. In January males moult into their breeding feathers in preparation for the elaborate displays they use to attract mates. He puffs up his neck to the size of a football and struts around, before tilting his head to expose the white chin feathers. This is followed by some fancy tail displays and some wing dances.

A male bustard in display.
Image by www.volganet.ru, CC BY-SA 3.0, via Wikimedia Commons

Females lay eggs in May or June, in nests that are simply scraped depressions on the ground. She lays one to three eggs that hatch in three to four weeks. Chicks are mobile almost right after birth, but take a while to develop courage to leave their mother. They grow adult feathers at two months of age, and learn to fly at three months. They can take care of themselves by the time winter rolls around, but stay around mom until their about a year old.

It’s pretty difficult for a bird as heavy as the bustard to get off the ground, so they prefer to run if they have a choice. Once they’re airborne though, great bustards are pretty good fliers. I wouldn’t believe it, looking at these birds, but it’s true. I’d love to see one in flight someday, I bet it’s pretty impressive.

Cover image by Francesco Veronesi from Italy, CC BY-SA 2.0, via Wikimedia Commons