When ANTS Fly . . .

[NickDG 23]

Over the years I've had many "discussions" with people regarding whether what we do can truly be called flight. Well, I've been vindicated. Freefall, according to the scientists in the following story is, "directed aerial descent."

NickD BASE 194

By Robert Roy Britt
Senior writer

http://www.msnbc.msn.com/id/6940729/

Updated: 1:30 p.m. ET Feb. 9, 2005

Add ants to the list of animals that can fly. Worker ants, the wingless kind.

Scientists call it gliding, or directed aerial descent. But just as one might say that flying squirrels fly, so do a type of ants called Cephalotes astratus. They live in rain forest treetops, and their newly discovered ability is a lifesaver.

Stephen Yanoviak of the University of Texas Medical Branch and University of Florida made the discovery by accident about two years ago while collecting mosquitoes for an unrelated project in the rain forest canopy near Iquitos, Peru.

The finding was announced Wednesday.

"When I brushed some of the ants off of the tree trunk, I noticed that they did not fall straight to the ground," Yanoviak told LiveScience. "Instead, they made a J-shaped cascade leading back to the tree trunk."

Yanoviak immediately suspected that his observation was something "new and exciting," but figured someone must have scooped him years ago. However, a quick read of past research revealed that his observation was novel.

Yanoviak started marking the ants with paint to follow their amazing journeys up and down the trees. He discussed the findings with Michael Kaspari of the Smithsonian Tropical Research Institute in Panama and the University of Oklahoma. A third colleague, Robert Dudley, with the University of California and also the Smithsonian, was brought in to create high-speed videos of the gliding wonders, among other things.

The team found that the ants downward journey comes in three phases: a 2- to 3-yard freefall and attempt to slow down, followed by a rapid midair turn back toward the tree trunk, and finished off with a steep but directed glide to the tree trunk.

The remarkably adapted ants are the first animals found to consistently glide backwards, other than microbes, some of which spend their entire lives gliding in directions hard to call backwards or forwards.

Yanoviak and his colleagues discovered that the gliding ants are able to return to their home tree trunk 85 percent of the time.

Once they make contact again with the trunk, the ants either cling to it with their sticky toes (called "tarsi" in ants) or fall a few more yards before gaining a foothold — at which point they begin their march back up the tree, often returning to the exact point from which they dropped, and typically within 10 minutes of their initial fall. Experiments done with blinded ants found that they rely on their vision to detect the tree trunk and guide their descent.

Smaller ants fell shorter distances. The scientists also found that ants called Pseudomyrmecinae were able to glide, but other arboreal ants they tested could not.

Look, ma, no parachute!

The falling ants’ first phase is called uncontrolled parachuting because they splay their legs in all directions in an effort to slow their fall by increasing drag. However, parachuting animals technically lack control over their trajectory.


Gliding or directed descent is initiated in phases two and three when the ants turn around and gain control over their flight path.

Their typical falling speed is 8 mph (4.3 meters per second), a fast clip for a creature less than a half-inch (1 centimeter) long. Sometimes, the tiny creatures bounce off the tree trunk the first time they hit it. When that happens, they're able to recover control rapidly and glide right back to the tree, Yanoviak said.

For arboreal animals, the ability to glide or fly or even parachute can be a life-or-death matter. Ants are frequently buffeted about by the wind or nearby mammals and birds, which can knock them off a branch or leaf to start tumbling down to a risky place — the forest understory, comprising the shrubs and trees that grow between the rain forest canopy and the ground cover. Moreover, some ants will voluntarily drop off tree trunks when approached by a foreign object.

In any case, the ability to self-rescue comes in handy. The understory and forest floor are full of hazards, not to mention terrain that is tough for tiny navigators, Kaspari said.

"An ant falling to the forest floor enters a dark world of mold and decomposition, of predators and scavengers, where the return trip is through a convoluted jungle of dead, accumulated leaves," Kaspari said. "Gliding is definitely the way to go, and we won’t be surprised if we find more examples of this behavior among wingless canopy insects."

Gliding is thought to be an important stage in the evolution of flight, scientists say.

Major trip
A fall of 30 yards is a huge distance for a canopy ant — 3,000 times the animal’s body length. For a human, this would be equivalent to being tossed 3.5 miles and then having to walk back home (although humans have different biomechanics and energy reserves that ants lack).

Ants often rely on chemical trails to find their way back to the nest. If they land in the understory and cannot find a trail or some other cue to get home, they are lost forever. Like many animals, ants are dependent on the work and contributions of the entire group, so the loss of any individual ant that falls and never returns is costly.

For this reason, evolution has favored traits like sticky toes and the ability for directed aerial descent to prevent the loss of workers, Yanoviak said.

The ants glide backwards because their hindlegs are longer than their forelegs. It is probably easier for them to get a quick grip on the tree with their hindlegs, as if using a fishing gaff or grappling hook, Yanoviak said.

It could also be that the shape of an ant's body only permits directional control in the air when facing backwards. However, Yanoviak said he recently discovered a type of ant called Camponotus that glides to the tree head-first. "The story will undoubtedly get more interesting the more we work on it," he said.

Other arboreal creatures that can glide include lizards, frogs and snakes. Still no word on whether pigs can fly.

[TomAiello 26]

Ants that can track. Now that's awesome.

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

[DexterBase 1]

Now that is truly fascinating. Thanks Nick.

[gweeks 1]

Quote

Ants that can track. Now that's awesome.

Yeah, but 85% of their jumps result in an object strike

[bodypilot1 0]

Those "tracking" ants are from Peru.

Next thing you know they'll be trying to say it's not a "track", but maybe a "Perumonauti" or something?


Ed

www.WestCoastWingsuits.com
www.PrecisionSkydiving.com

[base570 1]

I think Jeb is working closely with the ants and especially with their grappling hook legs

Jason
570

[LouDiamond 1]

Interesting. Having been to Iquitos,Peru among other countries in the Amazonian basin, I knew ants habitually built nests at various heights in trees. In Panama they actually build little cones along vines and branches that they reside in. If you spend any time what so ever walking in the jungle you quickly learn that brushing up against a tree or vines attached to a tree will cause a cascade of ants to rain down on you in what feels like an aerial attack.While I knew they fell ,I never knew they had the ability to control their fall as described in the article. Ants are everywhere in the jungle and all you have to do is look for the small 1-3" paths they sometimes wear into the ground from moving back and forth in what equates to an ant highway system. One other thing I am painfully aware of that may not be common knowledge is that apparently ants don't sleep. I have been on many a night movement in the jungle that has resulted in swarms of ants falling from the trees and biting everyone in the patrol.I will add this, Iquitos is off the hook for fun and festivities, just don't lick any of the frogs

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[Treejumps 0]

Very cool, but I don't think it is tracking, it sounds more like Antmonauti.

[davelepka 4]

Quote

Experiments done with blinded ants found that they rely on their vision to detect the tree trunk and guide their descent.

Hi, my name is Dan, and I've got my masters in entomology from UCLA. Right now I'm a research assistant on location in Peru. It's pretty exciting stuff, I'm in charge of poking the ants in the eyes before we drop them form a tree. Yeah, I'm livin' the dream.

[dmkellett 0]

it never ceases to amaze me what a puddle of slime and a couple of billion years can produce. base jumping creepy crawlies...............

[base704 0]

Damn that primordial ooze...

You can get a lot more done with a kind word and a gun than with a kind word alone.