PASADENA, Calif.Flies follow horizontal edges to regulate altitude, says a team of researchers from the California Institute of Technology (Caltech). This finding contradicts a previous model, which posited that insects adjust their height by visually measuring the motion beneath them as they fly.
This mechanism for controlling altitudein which the insects use their eyes to track horizontal edges in their environmentis very similar to the strategy insects use to steer left and right, the researchers note. "For people interested in how the tiny brains of these creatures can control such sophisticated behaviors, it's intriguing to realize that the same circuits and mechanisms that underlie steering may also be used to control altitude," says Michael Dickinson, the Esther M. and Abe M. Zarem Professor of Bioengineering at Caltech.
The paper describing these experiments is being published in the online edition of Current Biology.
Altitude control is a critical component of flight; unlike us earthbound humans, insects and other flying creatures need to control their height above the ground, or risk flying too high above itor crashing into it.
"Insects have to make their way through three dimensions," Dickinson notes. "We wanted to know how a fly chooses a particular altitude at which to fly, and why it isn't flying at some other height."
Insects, notes Dickinsonand fruit flies in particularhave long been used as a model for understanding the basic principles of vision and how it is used to control behavior. Thus, understanding how these tiny flies use visual cuesthe images, and changes in those images, that appear on their retinas as they move aroundto help them maneuver through a complex landscape is an important problem. Indeed, the results of such research are being used by engineers to control small flying robots.
The Caltech team was originally trying to test a model of altitude control in insects that ha
|Contact: Lori Oliwenstein|
California Institute of Technology