Most people tend to show a special revulsion towards reptiles. Perhaps it is because of that disturbing touch of poikilothermic or cold-blooded animals: a touch that many associate with that of death. In any case, it is an atavistic, irrational feeling that does not allow us to properly value the important role that reptiles play for the normal functioning of natural ecosystems. Because beyond this natural aversion, the truth is that reptiles fulfill a fundamental mission as pest controllers, keeping at bay, for example, the populations of insects and arachnids in our environment. That is the case of the Common gecko Tarentola mauritanica: the famous dragon that on summer nights is usually seen on the exterior walls and low roofs of buildings, crouching in the shadows; an animal as fascinating as it is beneficial to humans.
The Common gecko is one of the most common reptiles in the domestic environments of cities and towns, where it usually becomes a regular tenant (not a parasite) in our homes. Because despite all the legends that it carries against it, the truth is that this little saurian is totally harmless. The false belief that it feeds on clothes in closets is as absurd as it is unfair, because in addition to not causing any damage to the fabrics, its mere presence is the best deterrent agent for moths, which are the ones that lay their eggs between the clothes so that the larvae feed on them. Aware of this and many other virtues associated with their company, the rural people not only do not bother them but are complacent in their presence, because they know that with them hanging around the exterior of the house the presence of insects that they parasitize the home.
If we stop to observe its anatomy and behavior, far from being scared we will be fascinated by the biology of this curious nocturnal reptile. With a size of around 15 centimeters from head to tail, its skin, rough, scaly, grayish brown or ashy gray, allows it to blend in with the texture of the walls and ceilings in which it establishes its territory. It remains there for most of the day, half-hidden in any molding or protrusion, until night falls. Then it stealthily goes towards the limits of the shadows to stop, just before the light reveals its presence, and remain completely still for long minutes, waiting for the precise moment to pounce by surprise on its prey: moths, tipulas, flies and mosquitoes, spiders, beetles, cockroaches… their menu is made up of the least esteemed visitors to our homes.
If we look closely at the gecko’s fingers we will see that they are flat, globular and bulging. For years it was believed that they contained the suction cups that allowed it to run upside down on ceilings and vertical walls. Now we know that is not the case. Scientists have discovered that the secret of these reptiles to display such a surprising ability to adhere is in the sophisticated pili that they keep between the folds of their palms. Thanks to these filaments, they can move vertically across any surface, even window glass.
If we have the opportunity to admire these curious geckos in detail, with the help of binoculars, we will be struck by the appearance of their enormous eyes: golden, as if filled with glitter, and with a vertical black pupil that passes through the eyeball. from top to bottom to give it that appearance of a galactic creature. When the summer passes, any hole will serve as a burrow to spend the winter without causing any discomfort, reserving its strength to begin its surprising runs through walls and ceilings again as soon as spring arrives. Text: Jose Luis Gallego. La Vanguardia.