A super cool discovery has lit our imagination with the possibilities of a disco desert nightlife.
A German biologist named David Prötzel has found that web-footed geckos have skin markings that fluoresce neon green under UV light. In other words, these are glowing geckos!
Flourescence is a condition where light energy is absorbed and then emitted (or sent out) at longer wavelengths. This looks to us as a glow. In nature, the animal would appear to glow to its fellow geckos under moonlight. Why moonlight? Scientists believe that this is because the animals are noctural, or active at night.
Prötzel made the discovery while observing the nighttime behaviour of geckos that he keeps at home. These animals are noctural because their native habitat, the Namib desert in Namibia, is absolutely scorching during the day. They hide from this heat by using their webbed feet to dig under the sand and burrow underground. Then when the sun sets, they emerge and search for bugs and other treats to eat.
As Prötzel was watching his little friends scurry around in the evening, he thought to shine his UV light on them. Immediately, the marking along the undersides of the animals began to glow! Wow!
There are several examples of glowing creatures in nature, including scorpions, fish, and amphibians. But these geckos are the first reptiles to exhibit this exact trait, or feature: Glowing thanks to iridophores (say ih-RIH-doh-fors)—pigment-containing cells—in their skin.
Scientists are not certain why they are able to do this, but its seems likely that it is for communication. According to an interview with researcher Mark Scherz in Live Science, the markings would be visible to fellow geckos but "would be hidden from predators with higher vantage points, such as owls or jackals." (A vantage point is a position from which creatures see things around them.) In other words, a semi-secret signal to friends.
You can watch Prötzel talk about his glowing geckos, as well as meet his chameleon, in the video below. Though the video gets a bit complex while explaining iridophores, it's really striking watching these critters light up!