Hind wings help butterflies make swift turns to evade predators

Washington, Jan 9 (ANI): A new study has proposed that a butterfly's hind wings help it to make swift turns to evade predators, just like new tires allow race cars to take tight turns at high speeds.

According to a report in Cornell Chronicle Online, the study was undertaken by Tom Eisner, a world authority on animal behavior, ecology and evolution and the Jacob Gould Schurman Professor Emeritus of Chemical Ecology at Cornell University.

"To escape a predator, you don't have to be fast, you just have to be more erratic," said Eisner.

The study proposes that in the course of evolution, the ability of butterflies to evade predators became linked with bright coloring, as an added protection.

In evolutionary terms, gaudy colors are usually a sign to such predators as birds that a prey species has a protective quality, such as a bad taste or great agility, and that chasing them isn't worth the energy.

Anyone who has tried to net a colorful butterfly knows they are hard to catch, but this is the first study to show that a butterfly's hind wings are responsible for making them evasive.

Eisner and the research paper's lead author, Benjamin Jantzen, a doctoral student in philosophy of science at Carnegie Mellon University, clipped off the hind wings of butterflies and then filmed their flight using two cameras to get three-dimensional views of their flight trajectories.

Then, they analyzed and plotted on a computer the insects' flight velocity, acceleration, how fast they changed direction, the curvature of their path and more.

They found that clipping the back wings did not affect basic flight, but "we were able to show that removing the hind wings cut their turning acceleration in half," said Jantzen.

It was found that the butterfly's hind wings scoop air and provide extra force to quickly turn when chased.

"The wings are also colorful advertising for the whole group," said Jantzen.

"The colors say, we are butterflies, don't bother to chase us, because you won't catch us," he added.(ANI)