This invasive species arrived in Israel about a decade ago and has since surprised and disturbed with its impressive abilities – meet the Egyptian walled gecko
Guy Britzman, Zavit – Science and Environmental News Agency
The Egyptian wall gecko is not just another reptile that hides between rocks or building walls. Behind its success in establishing itself and thriving so far from its original home in North Africa lies a fascinating biological mechanism: in extreme weather, it changes itself from the inside out in order to survive. This gecko is an invasive species in Israel, and its ability to survive gives it an advantage over native species that it could displace and thus change the balance of power in the ecosystem and harm it. New research reveals how the Egyptian wall gecko adapts its internal organs and metabolic rate to the seasons – and why this is the secret to its success as an invader.
Cold season? Time to downsize
כמו reptiles Others, geckos' body temperature is affected by the environment and therefore they depend on the external temperature for various activities. In winter, when temperatures drop and food is scarce, geckos enter a state of "bromancy" - a type of cold hibernation. During this period, geckos reduce their activity to a minimum, and at the same time, their internal organs.
study A recently published study found that during the winter, the gecko's liver mass decreased by no less than 69 percent, the heart mass decreased by 37 percent, and the stomach mass decreased by 25 percent. "The internal organs shrink not only to save energy, but also to provide a source of nutrition and protein when food is not available," explains doctoral student Shahar Dubiner, the lead researcher from the laboratory of Prof. Shai Meiri and Prof. Eran Levin from the School of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University. In other words, in winter, the gecko feeds on its own internal organs.
Along with the reduction of internal organs, males have one organ that does the exact opposite: the testicles. The researchers found that during the winter, the testicles of these geckos double their mass in preparation for the breeding season in the spring. "The gecko prioritizes reproduction over everything else," says Dubiner. "That's why they manage to spread and build strong populations even in new environments."
The ability to adapt the body to changing conditions is critical for survival, and it is an advantage For invasive species At the expense of native species. “The invasive gecko is an example of a species that can take advantage of changing conditions, which is why we see it spreading into new areas,” he says. Thanks to this mechanism, the Egyptian walled gecko has been able to establish itself not only in hot deserts but also in urban environments and areas where temperatures change significantly between summer and winter.
For example, in built environments, geckos take advantage of artificial lighting that attracts insects, ambushes them, and preys on them. This is an advantage that allows them to thrive, but also increases competition with native species. “Invasive geckos create significant pressures on ecosystems, so it’s important to understand the mechanisms that allow them to succeed,” he says, in order to know how to eradicate their spread.
The Hitchhiking Gecko
The Egyptian wall gecko was first observed in Israel in 2012 on the walls of houses in Kibbutz Ein Gedi. Since then, additional individuals have been discovered in the southern Arava, and in 2024, individuals were also observed in Kibbutz Elipaz – indicating its continued spread in the area. It is known for its spiny body structure, wide toes, and serrated tail. The Nature and Parks Authority is working to reduce its population and is asking for the public’s help in identifying and reporting sightings, in order to prevent its ecological damage.
"The gecko knows how to cling, to travel inside cars, trucks, on platforms," she explains. In a statement from the Israel Nature and Parks Authority Dr. Tal Pollak, an ecologist from the Science Division. "The Ein Gedi water plant sends a lot of trucks all over the country and it has the potential to hitch a ride." In addition, "the gecko eats anything it can get its hands on. In North Africa, it has been documented eating gerbils. It eats other geckos and arthropods. It is a potential danger to anything that lives in its habitat that is smaller than it. When we found them in Ein Gedi, there were no other geckos there. Our assessment is that this gecko has eliminated all the local geckos. Its potential for damage is very great," Pollak notes in a statement. It is estimated that the arrival of the invader is the result of human activity, mainly through trade and transportation of goods.
The study's findings have broader implications than just geckos. Understanding these adaptive mechanisms could help researchers examine other invasive species and improve how we deal with the effects of climate change on animals in general. "The gecko is a testament to how creative and resilient animals can be in a changing environment," says Dubiner. "To maintain ecological balance, we need to understand how they operate and adjust our policies." The study highlights the need for intelligent monitoring and management of invasive species populations. Dubiner adds that the ability to introduce into Israel - intentionally or accidentally - species with high adaptive capacity like the gecko and that have been observed as "successful" invasive species elsewhere should be significantly limited.
New research on the Egyptian walled gecko provides a glimpse into a world of resilience, adaptation, and constant change. The gecko, which manages to change itself to survive, is a reminder of the power of natural processes and the fragility of the ecosystems on which we all depend.
More of the topic in Hayadan: (Beresheet is the Hebrew name for the book of Genesis)
