When researchers set out to study invasive lizard species in Florida, they weren’t expecting to stumble upon a groundbreaking, albeit unfortunate, discovery. Researchers were shocked to find a curly-tailed lizard so bloated they first assumed it was ready to lay eggs. However, a CT scan revealed something far more shocking: an unprecedented poop-to-body weight ratio.
“When we caught it, we just assumed the animal was ready to lay eggs,” said Natalie Claunch, a Ph.D. candidate in the University of Florida School of Natural Resources and Environment. “But when we went to feel for eggs, it just felt like it was full of Silly Putty.”
Claunch is studying invasive lizard populations in Florida, and she was shocked to find the unusual curly-tailed lizard. Along with Edward Stanley, director of the Florida Museum’s Digital Discovery and Dissemination Laboratory, she CT-scanned the lizard and found a massive fecal mass lodged in its enlarged stomach. It was so large that the surrounding organs were starting to atrophy, and the poop made up almost 80% of its body weight.
“I was blown away by how little room there was left for all the other organs – if you look at the 3D model, it has only a tiny space left over in its ribcage for the heart, lungs and liver,” Stanley said. “It must have been a very uncomfortable situation for the poor lizard.”
The record poop-to-body ratio was almost six times larger than the previous one, held by a Burmese python. The unfortunate lizard was unable to digest the nutrient-depleted bolus and was essentially starving because she couldn’t eat more.
The culprit? Pizza.
Curly-tailed lizards are native to the Bahamas and Cuba, and they were originally introduced to Florida in the 1940s to eat sugarcane pests. The female lizard was likely hunting insects and other prey when it was lured to a parking lot by pizza grease. Thinking it found an easy source of nutrients, the lizard started gulping the grease, ingesting a bit of sand with each bite of pizza grease. Then, it was unable to digest or expel the digestive bolus, which quickly built up inside of it.
It’s very unlikely for an animal to suffer this type of problem in nature. Lizards typically only eat small insects and can’t gulp a lot of sand at one time, and if they do, they’re likely to become prey for their own predators. It was once again human activity that paved the way for this to happen.
“New populations are still being reported and discovered – these lizards can hitchhike in cars, plant delivery trucks or boats, so they end up in a lot of disconnected places,” Claunch said. “We have so many invasive lizards in Florida that funding and person-power is typically directed toward ‘high priority’ species that are a direct threat to native threatened or endangered species, or to infrastructure, but the curly-tailed lizards’ successful spread makes it an interesting case.”
In a world where we often hear about the large-scale impacts of human activity on the environment (such as climate change and deforestation), this case reminds us that even seemingly inconsequential actions, like tossing pizza scraps, can have a profound and unpredictable impact on local ecosystems. While the discovery of the curly-tailed lizard with its record-breaking fecal mass may initially evoke surprise or even humor, the implications are serious and thought-provoking.
As Claunch and Stanley’s research underscores, invasive species often find themselves in new environments because of human actions, whether intentional or accidental. Once there, they interact with these ecosystems in ways we don’t fully understand, and the repercussions can be far-reaching. This extraordinary case of digestive obstruction serves as a vivid cautionary tale about how our everyday behaviors—like food waste—can create challenges for wildlife in unanticipated ways.
The researchers published their findings as a note in the Herpetological Review.