Western gang geckos don’t seem to win in a fight. However, this unassuming predator feeds on poisonous scorpions, and a field study published in March Biological Journal of the Linnaean Society shows how lizards take down such dangerous prey.
The geckos bite the scorpion and slam its head and upper body back and forth, knocking the scorpion to the ground, new high-speed video reveals. “The behavior is so fast that you can’t see what’s really going on,” says Rulon Clark, a biologist at San Diego State University. “[You] seeing the gecko lunge and then seeing this crazy motion blur…like trying to look at the wings of a hummingbird.”
Clark first noticed the behavior in the 1990s, during undergraduate fieldwork in the Sonoran Desert near Yuma, Arizona. When he returned with colleagues to study kangaroo rats and rattlesnakes, the team also filmed geckos. The researchers captured western banded geckos (Coleonyx variegatus) and dune scorpions (Smeringurus mesaensis) in the desert at night (along with harmless arthropods, like field crickets and sand roaches, for comparison), and documented the clashes.
Normal gecko feeding behavior generally involves lunging, grabbing prey in the mouth and chewing on it, Clark says. With scorpions, it’s totally different after the initial thrust. Such shake feeding is a known method for carnivores and adventurous eaters. For example, dolphins shake (and throw) octopuses before eating (Serial number: 04/25/17).
The fact that this delicate, cold-blooded species, which is not known for its speed, can pull off such physical turns is impressive, says Clark. songbirds called booby shrikes whip larger predators in circles (Serial number: 7/9/18), but at a lower frequency (11 hertz compared to geckos’ 14 hertz). whiptail lizards they also shake scorpions violently, but at unknown speeds. Closest documented match to gecko flapping feeding speed is small mammals shake themselves dry; guinea pigs also register around 14 Hz.
It is unclear how common this behavior is among geckos. And aside from generally subduing a poisonous enemy, how it works (killing the scorpion, immobilizing it, damaging its stinger, or reducing the amount of poison it injects) remains a mystery.