Dromornis, Thunderbird.

Posted by Rosemary Drisdelle Sep 19, 2006

How big was the biggest bird you ever saw? It was probably an Ostrich, the largest bird on earth today. An average ostrich stands about eight feet tall and weighs close to 250 lb. Now imagine a bird about the same height - about eight feet, but twice the weight - over 500 lb - and with a large head and a powerful beak. This is Bullockornis, thunderbird.

Thunderbirds (Dromornithidae) were large flightless birds of Australia. You might expect that they would be related to Emus, the current flightless birds of Australia, but it's thought that the thunderbirds were actually more closely related to present day ducks and geese. All extinct, they died out by about 23,000 BC.

The fossil remains of Bullockornis and other thunderbirds have been turning up in fossil beds in Australia since the 1800s, but recent finds have been more complete and thus, more revealing. The October 2006 issue of Discover magazine (page 10) describes the largest of these finds as coming from a bird ten feet tall and weighing 1000 lb (Dromornis sp.).

It's hard to imagine a bird that big. It's worse when you consider that these extremely large birds were probably also carnivores. The image brings to mind the Thunderbird of Native American lore, for some tribes, a huge bird figure with a taste for human flesh. I think I could do without adding Bullockornis or Dromornis to my life list.

Additional sources consulted:

Wroe, Stephen. "The Bird from Hell?" Nature Australia Vol 26, 7:56-63

Thunder Birds - the Family Dromornithidae'