The team found that, unlike flying squirrels that can glide horizontally for long distances, the ants fall at a relatively high velocity, around 4 meters per second (12 feet per second), and approach the tree at a steep angle. This means they frequently bounce off the trunk, though, as Yanoviak initially noted, they just make a 180 degree turn and try again ?usually with success.
What allows the ants to change direction so quickly is still a mystery. They have long, slightly flattened hind legs which, when combined with abdominal movements, might allow the ants to reorient in midair. They also have an unusual flattened head with flanges that could act as a rudder, Dudley said.
"My guess is that, by gliding backwards and using their legs and also their flat head with flanges, they could steer," he said, though more studies are needed before the question can be answered.
Yanoviak noted that worker ants are secondarily wingless, meaning they probably evolved the ability to glide after they lost their permanent wings, which were common in primitive ants.
"This discovery doesn't necessarily say something about the evolution of flight in terms of insect lineages, but it does give us good information about what kinds of morphologies are involved in the transition from just parachuting, or just falling uncontrolled, to being able to control where you land," Yanoviak said.
The gliding behavior would be a definite advantage for ants, like Cephalotes, that forage at the outer reaches of branches and are in greatest danger of being knocked off by wind gusts or passing monkeys. There is some evidence, Dudley said, that these ants sometimes purposely drop off the tree to avoid predators, evidently secure in the fact that they can glide back to the same tree.
"To me, one of the mo
Source:University of California - Berkeley