Skip to Content

What is the heaviest flying bird?

When it comes to flight, birds have mastered the art of overcoming gravity through evolution. Their light, hollow bones and powerful wing muscles allow even the largest of birds to take to the skies. However, some birds are able to fly despite being quite massive compared to their kin. So which bird claims the title of the heaviest flying bird?

Key Facts About Large Flying Birds

Before revealing the world’s heaviest flying bird, here are some key facts about these feathered giants:

  • Large birds tend to have higher wing loadings, meaning their wings are relatively small for their body weight. This requires faster flight to generate enough lift.
  • Many large flyers utilize thermal columns of rising hot air to help keep them aloft.
  • They often have large slotted wing tips that allow air to flow through the wings, reducing drag.
  • Some massive flyers like condors have extra large wingspans to compensate for their immense bulk.
  • Powerful chest muscles and cardiovascular systems give heavy birds the stamina for long flights.

Top 5 Heaviest Flying Birds

The largest of the flying birds truly stand out for their incredible bulk and aerial abilities. Here are the top 5 heaviest flyers in the world:

Rank Bird Average Weight
1 Kori Bustard 18 – 40 lbs
2 Great Bustard 17 – 42 lbs
3 Dalmatian Pelican 20 – 35 lbs
4 Mute Swan 23 – 35 lbs
5 Trumpeter Swan 20 – 30 lbs

1. Kori Bustard – 18-40 lbs

This African ground-dwelling bird is the heaviest living bird capable of flight. With some males weighing over 40 pounds, the Kori Bustard exceeds the size of many small dogs! It weighs more than 100 times the weight of a hummingbird. The Kori Bustard uses its massive wings, up to 5 feet across, to achieve lumbering takeoffs and labored flight.

2. Great Bustard – 17-42 lbs

Nearly rivaling the Kori Bustard is Europe’s own heavyweight flyer, the Great Bustard. The male Great Bustard displays dramatic white feathers during courtship that make it appears even more bulky. It runs and takes flight when disturbed, but prefers walking. With its weight often surpassing vultures and turkeys, it is one amazingly heavy bird.

3. Dalmatian Pelican – 20-35 lbs

This giant, all-white pelican breeds in eastern Europe and Asia. It dwarfs the more familiar brown pelicans seen along coasts. The Dalmatian Pelican has a wingspan up to 10 feet and a very large bill that it uses to scoop up fish. It flies in large flocks, drafting off each other to stay aloft despite weighing nearly as much as a small child!

4. Mute Swan – 23-35 lbs

Graceful yet massive, the Mute Swan is one of the most familiar of the world’s heavy flying birds. It is native across Eurasia but has also been introduced in North America. It is most notable for its aggression and its muted honking vocalizations. These large waterfowl can exceed 30 mph in flight when migrating or defending territory.

5. Trumpeter Swan – 20-30 lbs

The Trumpeter Swan of North America is a close relative of the Mute Swan. While not quite as heavy on average, it is equally adept at getting its 25+ lb bulk airborne. They announce their presence with a loud, sonorous trumpet call, very different from the mute’s quieter hisses and grunts. Trumpeter Swans form life-long pair bonds and fly together migrating between nesting and wintering grounds.

Other Sizeable Flyers

Many other birds around the world are impressively large flyers even if they don’t quite crack the top 5 heaviest. Here are some honorable mentions:

  • Andean Condor – 27 lbs
  • White Stork – 19 lbs
  • Somali Ostrich – 220 lbs (rarely flies)
  • Andean Goose – 18 lbs
  • Bald Eagle – 14 lbs
  • Lappet-faced Vulture – 20 lbs

Why Large Birds Can Fly

There are several key adaptations that allow the world’s heftiest birds to become airborne:

  • Low body density – Birds have lightweight bones that are rigid yet hollow. This skeleton is filled with air sacs. Low density provides lift.
  • Powerful flight muscles – The breast muscles generate tremendous power with each wing beat to propel the body into the air.
  • Large wings – Wings are sized to provide adequate lift for the bird’s weight. Large surface area produces more lift.
  • Wing loading – The ratio of weight to wing area is lower in heavy birds. More area balances the increased weight.
  • Streamlined shape – Fused collar bones, smooth feather coat, and tapered rear reduce drag in flight.


The ability of birds like the Kori Bustard and Great Bustard to become airborne shows the incredible power of avian flight. Using adaptations like lightweight skeletons, wide wingspans, and powerful muscles, even the world’s heaviest flying birds manage to defy gravity and take to the skies. Their massive bulk pushes the limits of size for powered flight among living animals. Next time you see a big bird lumbering down a runway for takeoff, appreciate the feat of engineering required for its sizeable body to leave the ground!