Printer Friendly

Why do two-sex geckos triumph? (Lizards).

The smell of one invading species of gecko has a mysterious influence on the activity of the defending species, but the voodoo doesn't work on first exposure, reports a researcher in Hawaii.

The Hawaiian Islands and many other islands in the Pacific Ocean have long been home to Lepidodactylas lugubris, a species of unisexual lizards. These geckos, which are effective colonizers, probably reached Hawaii with the Polynesians. As more people moved around the Pacific during World War II, a bigger species (Hemidactylus frenatus) that has two sexes started spreading. When H. frenatus arrives on an island, the population of the unisexual species plummets. Susan Brown, a biologist at the University of Hawaii at Hilo, wonders why.

Scientists had speculated that because the geckos of H. frenatus are bigger, they poach the unisexuals' food. Brown doubts that explanation, since there seem to be plenty of bugs to go around, she says.

Instead, she proposes that H. frenatus inhibits the behavior of the smaller species. When the L. lugubris geckos are on their own, "these ladies are really aggressive" she says. But when she put the two species together, the L. lugubris were subdued. Moreover, the H. frenatus scent by itself could dampen aggression and reduce egg laying by the smaller geckos.

In new work, she raised the unisexual geckos in individual quarters and then exposed them to the dreaded scent. The first time a unisexual gecko encountered the other species, the smaller gecko attacked with her species' usual fervor. On her next exposure, however, she became subdued. Brown suspects that such a subtle interaction between the species is fueling the spread of H. frenatus.--S.M.
COPYRIGHT 2003 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2003, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Science News
Article Type:Brief Article
Geographic Code:1U9HI
Date:Aug 2, 2003
Previous Article:Maybe what Polly wants is a new toy. (Parrots).
Next Article:The Empty Ocean.

Related Articles
Gecko toes tap intermolecular bonds.
Gecko Grip.
How gecko toes stick. (Getting a Grip).
Gecko-inspired adhesive is superstrong. (Caught on Tape).
Welcome To Lizard Lounge.
Color at night: geckos can distinguish hues by dim moonlight.
Twinkle toes: how geckos' sticky feet stay clean.
Nanotube carpet mimics gecko feet.
Get educated.

Terms of use | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters