Lizards take bigger risks when they are hungry

In the wild, every meal is a gamble. Animals like lizards must constantly weigh their options – play it safe or take a risk. The wrong choice could mean starvation. But the right one? A feast.

For some creatures, survival is about consistency. They take the sure thing, never gambling on an uncertain future. Others, when faced with starvation, throw caution to the wind.

A recent study led by Maria Thaker, professor at the Centre for Ecological Sciences (CES) at the Indian Institute of Science (IISc), reveals that certain tropical lizards fall into the latter category. Under the strain of hunger, they roll the dice – risking it all for a chance at a bigger meal.

The study challenges a long-standing belief. Reptiles have often been dismissed as slow, instinct-driven animals. But this research suggests otherwise. These creatures, despite their cold blood, are surprisingly calculating. They don’t just react; they strategize.

Hunger makes lizards take risks

Scientists call it the “risk-sensitive foraging hypothesis.” The idea is simple: hunger changes how animals approach risk. When full, they opt for reliable food sources, even if they’re small. When starving, they chase bigger, uncertain rewards.

Birds and mammals have demonstrated this behavior. But reptiles? They’ve largely been overlooked. After all, many can slow their metabolism and enter a state of torpor when food is scarce. But tropical lizards don’t have that luxury.

“Reptiles can slow down their metabolism a lot. So, in food-scarce times like winter, they go into torpor (hibernation) to avoid starving to death,” explained Professor Thaker.

“In the tropics, however, reptiles are exposed to warm temperatures all year round and cannot slow their metabolism down enough to get through tough (food lean) times. We expected that lizards in the tropics should have evolved the ability to assess food options, because if they don’t, they may risk starving to death.”

Starving lizards make riskier choices

To test this, the researchers turned to the rock agama (Psammophilus dorsalis), a lizard commonly found in and around cities like Bengaluru. These small, fast-moving reptiles navigate both natural and urban landscapes, making them ideal for studying adaptive behavior.

The team devised a straightforward test. First, they split the lizards into two groups. One group received plenty of food, while the other received nothing for 48 hours.

Next, both groups were presented with a choice. One option offered two mealworms, guaranteed. The other was a gamble – either zero or four mealworms. Would hunger change their decisions?

Risk-taking lizards

The results showed that well-fed lizards stuck to the safe bet – two mealworms, no surprises. But the starved lizards? They took the risk, picking the unpredictable option far more often.

“We found that well-fed lizards played it safe, opting for the guaranteed two mealworms option,” said study lead author and PhD student Avik Banerjee.

“On the other hand, starved lizards took greater risks, frequently choosing the variable option which has the potential to get them four mealworms. Remarkably, both groups of lizards ended up with similar net food gains by the end of the trials, indicating that the different strategies worked.”

A survival strategy, not a fluke

The study reshapes how we see reptile decision-making. Unlike their cold-climate cousins, which rely on metabolic slowdowns, tropical lizards must stay active. Their survival depends on making smart, timely choices.

And this goes beyond instinct. The lizards remembered their options, assessed the risks, and made choices based on their needs. That’s strategy, not reflex.

Lizards remember past choices

For decades, intelligence has been linked primarily to mammals and birds. But reptiles are proving to be far more complex than previously assumed.

“We think that humans have an excellent ability to assess our environment and take calculated risks when needed. But lizards can too,” said Professor Thaker.

“The fact that the rock agamas can remember different options and make appropriate choices to secure their survival is rather cool. We are surrounded by very clever and calculating animals.”

Lizards, often overlooked, might just be thinking more than we ever gave them credit for. And if they can weigh risks and rewards – who knows what else they’re capable of?

The study is published in the journal Biology Letters.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–