Birds in flight often arrange themselves in aerodynamically optimum positions, according to a new paper in thejournal Nature
that helps to explain how birds fly in such impressive formations. Lead researcher Steven Portugal and his colleagues focused their study on northern bald ibises, but many bird species also exhibit the amazing flight behavior. Portugal, a University of London Royal Veterinary College researcher, told Discovery News that birds could be using three things to achieve their flying precision: "(1) vision – watching the bird in flight to get all the information they need, (2) feathers – sensing the changes in pressure, wind etc. through their flight feathers, and (3) positive feedback – i.e. they just fly around and when it feels easier/better they stay in that position."
The researchers determined that birds try to find "good air," meaning airflows (not just wind, but even the air created by other flapping wings) that minimize their energy expenditure and help them to get where they plan to go. Conversely, birds avoid regions of "bad air" that could work against them.
Many birds fly in distinctive V-formations. Portugal said, "The intricate mechanisms involved in V formation flight indicate remarkable awareness and ability of birds to respond to the wing path of nearby flock-mates. Birds in V formation seem to have developed complex phasing strategies to cope with the dynamic wakes (turbulent air) produced by flapping wings."
H.K. Job, Wikimedia Commons
Military planes sometimes fly in what is known as an "echelon formation," which mirrors nearly the exact same flight formation of many birds. This particular bird version is a variation of the "V," only with a rounded edge.
The U.S. Navy's famous flight demonstration squadron The Blue Angels often flies in a trademark "diamond formation" once popularized by fighter-bomber pilots. In it, the pilots maintain an 18-inch wing tip to canopy separation. Birds can fly even more tightly together.
The term "murmuration" refers to a flock of starlings. These birds can create dramatic patterns in the sky, such as this one over marshlands near Tønder, Denmark. Other small birds, such as sandpipers, may also create what look to be dazzling aerial ballets in the sky as they fly en masse.
Rupert Ganzer, Flicker
Even birds flying very close to land can do so in remarkable unison. Here, a formation was photographed as the birds flew over the beach at Camperduin in the Netherlands.
Daniel Jolivet, Flickr
The classic "V" formation has all sorts of variations. In this case, three separate -- yet united -- groups create an arrow-like effect in the sky.
Mark Kent, Flickr
Alfred Hitchcock's classic horror film "The Birds" included many scenes where numerous birds blanketed the sky. Up close, these starlings look small and harmless but, as a huge murmuration, their power becomes evident.
From the earliest planes to those in design today, aircraft have been modeled after birds. It's no wonder. Every inch of this sleek northern bald ibis, snapped while flying over Tuscany, adds to the bird's flying prowess. Its 53-inch wingspan and powerful, synchronized wing beats must have captivated people in the ancient world too, since ancient Egyptians and other early cultures featured the birds prominently in their artwork and legends.
The world’s largest-ever flying bird has just been identified, according to scientists who say the bird’s wingspan was about 24 feet long, which is around the same length as a dance floor suitable for 160 people.
The long-extinct bird, named Pelagornis sandersi in honor of retired Charleston Museum curator Albert Sanders, was appropriately unearthed at what is now the site of the Charleston International Airport. This literal big bird, described in the latest issue of the Proceedings of the National Academy of Sciences, took off from the site in Charleston, S.C., 25 to 28 million years ago.
Its fossils were so big that some of them had to be dug out with a backhoe.
“The upper wing bone alone was longer than my arm,” co-author Dan Ksepka, curator of science at the Bruce Museum in Greenwich, Conn., said in a press release.
Ksepka and his team believe that Pelagornis sandersi was twice as big as the largest flying bird alive today: the royal albatross. It also pushes the current record holder for largest flying bird ever to fly the skies, Argentavis magnificens, into second place.
Analysis of P. sandersi’s remains strongly suggest that it could fly.
The enormous bird had paper-thin hollow bones, stumpy legs and giant wings that would have made it at home in the air, but awkward on land, according to the researchers. They believe its impressive wings would have allowed for efficient gliding.
But how could such a bird have taken off? Its wings were too big to flap and generate lift from a standing position. The wings would have just hit the ground with a thud.
Ksepka and his team created computer simulations and determined that the bird probably ran downhill into a headwind or took advantage of air gusts to get aloft, similar to what hang gliders do.
Once airborne, it must have been quite a sight. Riding on air currents that rise from the ocean’s surface, the big bird could have soared for miles over the open ocean without flapping its wings. It hunted marine life, so it must have occasionally swooped down to the water to feed on soft-bodied prey like squid and eels, according to the new study.
“That’s important in the ocean, where food is patchy,” said Ksepka.
He and his colleagues hope to learn why this bird and its relatives eventually died out. Note that the bird lived long after non-avian dinosaurs went extinct around 65 million years ago, so that extinction event definitely did not do these birds in.
Information about the birds could also lead to new and improved aircraft that one day might take to the skies in about the same spot where this bird once did all those years ago.
Image: A recreation of the new fossil species Pelagornis sandersi. Credit: Liz Bradford.