Skip to comments.Takeoffs a problem for giant bird (Argentavis magnificens, 23-foot wingspan)
Posted on 07/02/2007 9:54:54 PM PDT by NormsRevenge
WASHINGTON - Weighing in at 150 pounds or more, the all-time biggest bird couldn't just hop into the air and fly away, researchers say. A team led by Sankar Chatterjee of Texas Tech University used computer programs originally designed for aircraft to analyze the probable flight characteristics of Argentavis magnificens, a giant bird that lived in South America 6 million years ago. Like today's condors and other large birds, Argentavis would have had to rely on updrafts to remain in the air.
Doing so, it could have soared for long distances, they conclude in a paper in Tuesday's edition of Proceedings of the National Academy of Sciences.
Remains of Argentavis have been found both in the plains of northern Argentina, called pampas, and also in the foothills of the Andes.
With a wingspan of about 23 feet, Argentavis is the largest known flying bird, the researchers said.
By measuring the size of the bones they determined how large its flight muscles would have been, and calculated that it would not have been capable of takeoff or of sustained flight just by flapping its wings.
"Gliding would not be a problem, it would be the takeoff, that is the main limiting factor," Chatterjee said in a telephone interview. "In the mountains, takeoff was not a problem, but sooner or later it would come to the plain."
As far as getting airborne there, Chatterjee suggested the birds could launch from a high point in the foothills. In addition, with a slight headwind and as little as a 10-degree downhill slope they would probably have been able to take off in a running start, the researchers said.
But it looks like this was just about the size limit for a flying bird, he said.
A steady east wind blowing from the Atlantic Ocean and rising in the foothills of the mountains would have created ideal conditions for soaring flight, in which they estimated the giant hunter could reach 40 mph.
"Large broad-winged landbirds, such as eagles, buzzards, storks and vultures with slotted wings are masters of thermals and travel cross-country by gliding in circles," they researchers said.
Thermals are areas of rising warm air and can often be easily determined from a distance because cumulus clouds develop above them when the moisture in that air cools and condenses.
In every culture there are tales of large birds, whether local Indians, Hindus or others, Chatterjee observed.
"Now we can show that they actually existed," he said, though this bird lived millions of years before humans walked the planet.
And with a skull nearly two feet long, Argentavis "was catching sizable prey with its formidable beak."
The research was funded by the National Geographic Society and Texas Tech University.
This handout illustration recieved courtesy of Proceedings of the National Academy of Sciences (PNAS) shows Argentavis magnificens, the world's largest known flying bird with a wingspan of 7 meters, (7.6 yds) about the size of a Cessna 152 aircraft, soaring across the Miocene skies of the Argentinean Pampas six million years ago. Like todayâs condors, Argentavis was a lazy glider that relied either on updrafts, in the rocky Andes, or thermals, on the grassy pampas, to provide lifting power.(AFP/PNAS-HO/Jeff Martz)
Proceedings of the National Academy of Sciences: http://www.pnas.org
NOTE: This is an artist conception - no one was there to witness this creature
So what does it do? Walk half a mile up the hill carrying a deer leg in its beak? Or does it nab prey in a low swoop? I wonder how much it could carry? As for the prey struggling - it could just drop it from fifty feet and pick it up again.
Frigate birds can't take off from but a height either - they skim fish off the water surface - it's not a question of eventually coming to the plain - they never land except on their high place roosts.
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I know I’m going to get flamed for this, because I don’t even believe it myself, but a lot of these really huge creatures would make more sense if gravity was less in the far distant past.
Gravity wasn’t weaker, but the atmosphere was thicker.
For which he might receive the Pullet Surprise!
Megafauna and the attenuated gravity of the antique system.
Dozen matter if he does. ;’)
Molt of the time...
Dr. Kenneth E. Campbell, (one of the discoverers) in front of the 25 ft. wingspan Argentavis Magnificens. Display seen at the Natural History Museum, Los Angeles. The feather size from such a bird is estimated to have been 1.5 meters long (60 inches); and 20 centimeters wide (8 inches). Such a huge size would make the feather at least 5 feet long, similar to the one described as coming from the Desert Southwest in:
Also known as the "teratorn" and the Legendary Thunderbird.
The site link above is to one such Thunderbird site.
This may be at least part of the legends concerning the "Roc" ( or Rook? ) of Arabian Tale's and Sinbad fame.
As to flight, the article refers to places like the Andes and Argentine Pampas as having the wind currents necessary for flight.
I suggest the Great Plains, Rockies and Appalachian mountains of North America could also have provided habitat for what the Native Americans called the Thunder Bird.
Anecdote suggests the Thunder Bird also utilized storm fronts as lifting forces to travel large distances. ( And possibly for takeoffs in lower altitudes )
These birds probably fall into the category ( class? ) of Mammoth, Giant Sloth, Giant Elk, Cave Bear, etc. that disappeared about the same time ancient man began colonizing the americas.
That would date some of the oral legends handed down as much as 25,000 years, 10 to 12,000 for the Clovis cultures.
I wouldn’t want to be under one when it relieved itself from aloft.
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