782. What is the largest bird known to have lived? The giant moa of New Zealand which apparently became extinct about 5 centuries ago stood, according to reproductions of their skeletons, as much as 12 feet tall. They were flightless birds built for running. The giant moa belonged to a large family that ranged in size from the 12-foot giants down to small species about the size of turkeys.
Lake in Pyramid Valley, South Island, New Zealand, 2008
783. What caused the extinction of the giant moas? The cause of their extinction about the fourteenth century is not known. However, some were eaten by the primitive people who then inhabited New Zealand. Others died in “graveyards” containing hundreds of skeletons of moas, which suggests that they may have been herded together by some catastrophe, perhaps fire, that caused simulataneous death to great numbers. In Pyramid Valley of South Island a very sticky lake deposit over which a thin film of humus and vegetation spread trapped many moas. The heavy birds broke through the surface and were caught in the treacherous mire where they floundered helplessly and died.
Sir Richard Owen KCB (1804-1892) and the skeleton of a Giant moa. Owen, a prominent biologist, paleontologist and comparative anatomist, coined the word Dinosauria (meaning "Terrible Reptile" or "Fearfully Great Reptile") and was the driving force behind the establishment of the British Museum of Natural History in London in 1881.
784. Have any other birds approached the giant moa in size? The elephant bird (Aepyornis maximus) may have weighed as much as 1,000 pounds and reached 11 feet in height. Like the giant moa it was flightless and resembled an ostrich in form.
Elephant Bird -- Artist's rendering and skeleton
Reader Note: For more on the extinction of the Giant moa and other animals inhabiting the Pyramid Valley, see this from Time magazine, April 25, 1949. And also this.
Text excerpted from: 1001 Questions Answered About Birds by Allan D. Cruickshank and Helen G. Cruickshank (Toronto, General Publishing Company, 1958)