Fall 2021 Children's Sneak Previews

Webinar Held On Conservation Of The Samaná Banded Gecko

Image: Natusfera

Barrick Pueblo Viejo recently hosted the webinar "From Critical to Near Threatened: A Look at the Conservation of the Samaná Banded Gecko," highlighting the successful reclassification of Sphaerodactylus samanensis, a gecko species endemic to the Dominican Republic, from "Critically Endangered" to "Near Threatened" by the IUCN.

The event featured prominent herpetologist Germán Chávez, whose collaborative research with Dominican scientists has been vital in reassessing the conservation status of various reptiles across Latin America.

The webinar attracted a diverse audience, including scientists, students, environmental professionals, and private sector representatives. It underscored the importance of collaborative conservation efforts and served as a case study for how mining operations, like those of Barrick Pueblo Viejo, can align with ecological stewardship.

How A Western Banded Gecko Eats A Scorpion

Western banded geckos don't look like they'd win in a fight. Yet this unassuming predator dines on venomous scorpions, and a field study published in the March Biological Journal of the Linnean Society shows how the lizards take down such perilous prey.

Geckos bite the scorpion and thrash their heads and upper bodies back and forth, body-slamming the scorpion against the ground, new high-speed video reveals. "The behavior is so fast that you can't see what's actually happening," says San Diego State University biologist Rulon Clark. "[You] see the gecko lunge and then see this crazy blur of motion … like trying to watch the wings of a hummingbird."

Clark first noticed the behavior in the 1990s, during undergraduate fieldwork in the Sonoran Desert near Yuma, Ariz. When he returned with colleagues to study kangaroo rats and rattlesnakes, the team filmed geckos as well. 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, to compare), and documented the showdowns.

Watch western banded geckos demolish some scorpions.

Normal gecko feeding behavior usually involves lunging out, grabbing prey with their mouth, and chomping it, says Clark. With scorpions, it's totally different after the initial lunge. Such shake feeding is a known method for carnivores and adventurous eaters. For instance, dolphins shake (and toss) octopuses before eating (SN: 4/25/17).

The fact that this delicate, cold-blooded species not known for speed can achieve such physical gyrations is impressive, Clark says. Songbirds called loggerhead shrikes whip larger predators in circles (SN: 9/7/18), but at a lower frequency (11 hertz compared to 14 Hz in geckos). Whiptail lizards also violently shake scorpions, but at unknown speeds. The closest documented match to the speed  of gecko shake feeding is small mammals shaking themselves dry; guinea pigs clock in at around 14 Hz, as well.

It's unclear how common this behavior is among geckos. And aside from generally subduing a venomous foe, how it works — killing the scorpion, immobilizing it, damaging its stinger, or reducing how much venom gets injected — remains a mystery.

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Gecko Takes Down Venomous Scorpion In Dramatic Slow-Motion Video

Dramatic footage has been shared online capturing the moment a gecko went toe-to-tarsal claw with a venomous scorpion.

The video was shared with Newsweek by researchers from San Diego State University (SDSU) in California who have been studying the unique feeding behavior of western banded geckos when consuming scorpions.

Western banded geckos are considered mild-mannered creatures, known for quickly pouncing and feasting on insect prey like crickets, beetles and other small arthropods that reside in their environment.

However, as the footage shows, when they catch scorpions their demeanor changes entirely. After catching the scorpions, these geckos proceed to violently writhe around and shake themselves from side to side at high speeds. In the process, their prey is smashed back and forth against the ground until entirely immobilized.

Researchers believe the blunt force trauma of this frenzied attack leaves the scorpions, a formidable enough species, unable to fight back. When the dust finally settles on it all, the gecko is able to devour the scorpion in peace.

The research, published in the Biological Journal of the Linnean Society, was conducted by SDSU biologist Rulon Clark and Malachi Whitford, a graduate student in the joint SDSU and University of California, Davis Ph.D. Program in ecology who is now a professor of environmental science at Clovis Community College.

Whitford told the SDSU Newscenter: "They seem to be kind of body slamming the scorpions into the ground. If you ever see seals, they'll pick up fish and they'll slap them against the water. I think geckos are doing essentially the same thing."

Clark noticed the geckos' distinctive behavior while studying flat-tailed horned lizards at the Barry M. Goldwater Bombing Range in the Sonoran Desert near Yuma, Arizona, during his time as an undergraduate research assistant at Utah State University in the 1990s

He returned there, years later, to study how kangaroo rats fend off rattlesnakes using their powerful limbs, with the resulting footage going viral on social media.

It was during this trip that Clark and Whitford filmed the gecko interactions with scorpions and other prey using high-speed video cameras capable of capturing up to 1,200 frames per second.

This allowed them and viewers online to examine the geckos' frenetic movements in pinpoint detail. While they filmed several interactions with various bugs and insects, it was the encounters with scorpions that proved the most remarkable.

As Whitford puts it, geckos, which are most active at night, are probably "the least intimidating animal" you are ever likely to meet—but they discovered that all changes when they encounter a scorpion.

"They go like berserker mode. And watching that play out and how violent it actually is, how rapidly they're actually shaking, how much they're actually trying to apparently damage the scorpion in some way, that was by far the most impressive and exciting part of this study."

The slow-motion camera, meanwhile, allowed them to examine the minutiae of the method. Clark explained: "You can see what they're doing is rotating their head and body back and forth in this cyclic motion to thrash this thing around—against objects, against the ground—using torsional force to incapacitate the scorpion."

According to the researchers, this scorpion-thrashing technique has been identified in one other species of lizard and could be designed to minimize the likelihood of them being harmed by these predatory arachnids.

"When you're dealing with dangerous prey you have to adopt strategies to mitigate that risk," Whitford explained in the SDSU Newscenter.

"So like with roadrunners dealing with rattlesnakes, they don't just run up and eat it like they could another snake. They have to try and manage that risk of being bit and injected with venom. It's clearly a strategy to mitigate that risk because most of the prey that they're eating doesn't pose any risks to them at all."

One possibility is that the geckos shake their bodies so violently to make it impossible for the scorpions to inject them with venom. Clark suggests the whipping back and forth may stop the scorpion and disable their stinger, but Whitford thinks it could be simply the blunt force trauma that stops their prey from fighting back.

It's also unclear as to whether geckos have developed a resistance to scorpion venom, with the researchers noting that the reptiles are often stung during these attacks.

Ultimately more research is required but the findings nevertheless highlight how geckos appear to have evolved to combat more dangerous prey in their environment with the resulting encounters making for fascinating viewing.

A western banded gecko. Researchers have captured footage of the dramatic technique these seemingly docile reptiles use to tackle venomous scorpions. A western banded gecko. Researchers have captured footage of the dramatic technique these seemingly docile reptiles use to tackle venomous scorpions. SDSU Clark Lab

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