Invading giant geckos get stuck on a single building

27 October 2016, updated 27 October 2016

By Emily Benson

An unlikely foe has kept a marauding band of non-native geckos from taking over a tiny Mediterranean island: dust on their feet.

The stowaways to an island near Corsica are trapped on a single concrete building and are unable to leave, as dust elsewhere on the island makes them slip or stop in their tracks as they try to shake off the grime.

Most geckos can scamper up rocks and stroll across ceilings thanks to adhesive pads on their toes. But whereas some sport sticky rows that cover the bottom of each digit, others have just two adhesive spots at the tip of each toe, says Anthony Russell at the University of Calgary in Canada.

 “We really didn’t know before why you’ve got these two fundamentally different designs,” Russell says. But now, a study by Russell and Michel-Jean Delaugerre at the Conservatoire du Littoral in Bastia, France, hints at an answer.

The pair examined two gecko species on Giraglia, a 10-hectare island off the northern coast of Corsica.

Euleptes europaea has toe-tip pads and is native to the island, roaming freely across the dusty landscape. Conversely, Tarentola mauritanica is a larger gecko with full-toe pads, and is native to other parts of the Mediterranean. The authors found that the invader was confined to a single concrete structure.

Continued