10 Interesting Facts about Gila Monster

You may have heard about the Gila monster. You may have even seen one with your own eyes in the wild.

But maybe you don’t know as much about the animal as you’d like. So, allow me to correct that right here and now.

Today, we will discuss the 10 most interesting facts about the Gila monster, some of which I guarantee you’re not aware of. Enough talking, let’s get to it!

1. Gila Monsters are Venomous Lizards

Gila monsters are slow lizards, so they rely on their venom to make up for it. These lizards don’t have venomous glands like snakes do. Instead, the venom is produced and delivered through special grooves located on the reptile’s lower jaw. The venom will then oil up the bottom teeth and enter the prey upon biting.

Gila’s venom is neurotoxic, comprising a group of toxins known as oxamide-active peptides. These attack the central nervous system and inflict muscle paralysis due to messing up the nervous system’s electric signals.

The only problem is that the Gila monster only injects low quantities of venom with every bite. That’s because, unlike snakes, this lizard doesn’t have venom glands that can produce and inject lethal doses of venom.

With snakes, the venom glands are located right underneath the front hollow teeth. As the snake bites, the prey’s flesh presses against the mouth palate and the venom glands, forcing them to squeeze the venom into the wound.

But Gilas lack this mechanism, so they make up for it by biting repeatedly and holding onto their prey for up to 10 minutes or more.

This is to make up for the low quantity of venom, as well as for its slow-acting mechanism. The venom’s effectiveness depends on the prey’s size and metabolism. The reptile’s venom has a delayed response in humans because of it, so symptoms may not appear until hours after the bite.

Fortunately, Gila’s bite isn’t deadly in the vast majority of cases. Even so, you need to seek medical attention if bitten because complications may appear anyway. This includes anaphylactic shock, which can turn deadly.

Unfortunately, there’s no antivenom against the Gila monster, but research is still ongoing on the subject.

Recent studies have found similarities between the Gila venom and that of the Mexican beaded lizard, suggesting that the same antivenom can be used for both. But these are merely speculations for now, and the treatment is considered experimental at best.

2. Gila Monsters Have a Strong Bite

Gila monsters measure up to 2 feet and weigh up to 5 pounds, although many specimens are smaller than that. Knowing these measurements, it then comes as a total shock that the lizard’s bite force can measure up to 200 psi.

Sometimes even more. To understand the reptile’s sheer power, consider that the average human bite force revolves around 110-140 psi. The maximum would be around 160 psi.

This makes Gila’s bite 60-70% higher than that of the average human. This is nothing when compared to other reptiles, as alligators, for instance, can deliver a bite force of up to 2,000 psi. But it’s definitely impressive based on the ratio between the lizard’s body, and its bite force output.

Gila’s jaw strength makes sense from an evolutionary perspective because this is a slow lizard with little antivenom available. So, it had to work its way around its deficiencies to improve its hunting abilities.

Developing improved jaw strength and muscle resilience was the way to go. This allows the Gila monster to bite and hold its prey for longer, allowing for more venom to flow into the wound.

3. Gila Monsters are Carnivores

Gila monsters are actually scavenging carnivores, which is another way of saying they eat anything, alive or dead.

Some of the animal’s preferred meals include lizards, snakes, mammals, birds, frogs, insects, and even carrion and leftovers from other carnivorous animals.

They even consume eggs whenever they find them, and they’re quite adept at it. Gila monsters have a good sense of smell, allowing them to detect eggs buried in the ground. These provide them with a lot of nutritional value until something better comes along.

4. Gila Monsters Have Slow Metabolism

This shouldn’t pop as a surprise, given that Gila monsters are reptiles and all reptiles have slow metabolisms. But you couldn’t have guessed the extent of this animal’s adaptability.

Some studies suggest that Gila monsters can get all the calories they require for an entire year in only 3-4 meals. This is thanks to 2 evolutionary adaptations that make Gila monsters extremely resilient and hardy.

The first one is the reptile’s ability to store fat in its tail and other places. This isn’t a biological wonder in and of itself since all animals do that, including humans.

The difference is that Gila monsters can live off of those fat reserves far longer than any other animal. They can go for several months without any food.

The second one is that Gila monsters can consume obscene amounts of food during one meal. More precisely, we’re talking about a third of the reptile’s total body weight.

This would be the equivalent of a 200-pound human gulping down nearly 70 pounds worth of food in one meal.

This means that Gila monsters are fine with eating whenever they can and are not under any stress to find food, unlike other animals.

5. Gila Monsters are Protected Species

Gila monsters don’t currently rank as endangered, but they’re not in the clean either. IUCN, or the International Union for Conservation of Nature, qualifies Gila monsters as a species of least concern. This means that the population is relatively stable across the board.

This is where the ‘however’ part comes in. However, Gila monsters are protected in some states, with international trade falling under Convention on International Trade in Endangered Species of Wild Fauna and Flora regulations. Or CITES, if you want to avoid the spelling convo.

The main factors causing the decline of Gila monster populations include natural predation (coyotes, birds of prey, and even humans) and habitat destruction and fragmentation.

These lizards are still durable and resilient, so they’ll likely adapt to whatever Mother Nature throws their way. But they still require our support to continue to thrive in an ever-changing world.

6. Gila Monsters Have Slow Reproductive Rates

Gila monsters reproduce very slowly, which is part of why their population is dwindling in some parts of the world. The sad part about it is that the Gila monster’s slow reproductive rates make sense.

This is the reptile adapting to its habitat, as bringing too many offspring in a desertic region low in food and resources aren’t benefitting anyone. So, these reptiles have evolved only to produce 2-8 eggs per year, which take approximately 3 months to hatch, depending on the environmental conditions.

Add to this the risk of predators discovering and consuming the eggs, and you can see why the situation isn’t exactly sparkly-pink for these lizards.

Then there’s the problem of the long timespan necessary for Gila monsters to reach sexual maturity. These lizards are considered sexually mature at the age of 4 or 5. So, the time window during which Gilas cannot produce offspring is quite large.

A lot of things can happen during this time that could lead to the lizard’s death.

Good thing that Gila monsters can live for decades as adults, which makes up for it a bit.

7. Gila Monsters’ Bright Coloration Warn Predators

Gila monsters exhibit very low color and pattern variation. They pretty much all look the same, with thick bodies, wide heads, and black and yellow as their main colors.

The color pattern is fairly random, with color splashes covering the entire body. The tail is generally sand-yellow with black bands, while the face is invariably black.

This flashy coloration has 2 purposes: to help the animal blend in its environment and warn predators of the lizard’s venomous nature. The black head is a pretty good indicator of the latter.

But the coloring isn’t the Gila’s only defense mechanism. Its claws, bite force, and sheer strength also contribute to the reptile’s defenses.

It’s not uncommon for Gila monsters to fight back against their predators, which is really all they can do since fleeing isn’t an option. In that case, their venomous bite, jaw pressure, and piercing claws are no joke.

Finally, Gila monsters have thick and bumpy skin covered by armored scales. These make the reptile difficult to hold down, sting, or bite through. Many predators are simply discouraged from even trying.

8. Gila Monsters are Slow Lizards

Gila monsters are not designed for speed. Their bulky bodies, short legs, and thick heads force them to take their time when doing anything.

While this may sound detrimental to a lizard that also has natural predators, it actually makes sense from an evolutionary perspective.

The lizard’s slow movement allows it to conserve energy, which plays into its slow metabolism and the reptile’s less reliance on food.

Not to mention, Gila monsters don’t have that many natural predators to begin with. The lizard’s skin is hard to pierce, and few animals are willing to hunt a venomous and powerful lizard, to begin with.

So, instead of relying on speed to evade predation, Gila monsters rely on their bite power, venom, warning colors, and ability to blend in their environment.

9. Gila Monsters Can Survive Months Without Food

All reptiles can survive without food for far longer than any other animal family on earth. Some exceptions may be allowed, of course. Most importantly, the reptile’s ability to fast for extended periods of time doesn’t include torpor or hibernation, which would justify the behavior.

Instead, Gila monsters are naturally resilient and owe their resistance to nutrient deprivation to their slow metabolism and ability to store fat and nutrients in their bodies.

This allows Gila monsters to last months without food, but the exact maximum timespan is difficult to calculate. This being said, not all Gila monsters are equally as resilient.

The reptile’s adaptability to nutrient deprivation depends on its age, size, health, and stored fat, among other things. It’s natural for many Gila monsters to have huge meals before the scorching summer when food is more difficult to find and procure.

The same behavior occurs before breeding, as Gila females tend to fast for months during the breeding season.

10. Gila Monsters Can Live for Decades

The lifespan of Gila monsters is subject to debate, as claims vary, depending on where you look.

However, the general consensus is that Gila monsters can live between 15 and 20 years in the wild and slightly over 20 years in captivity. The current record for the oldest Gila monster grown in captivity is 36 years.

A few mentions here. Gila monsters tend to live longer in captivity due to a constant supply of food and water, the lack of natural predation, and personalized veterinarian care, decreasing the incidence of major health issues.

This results in a longer lifespan and a higher quality of life in an ideal scenario.

The problem is that Gila monsters aren’t exactly great as pets. These animals are much feral than other lizards and reptiles. They don’t adapt well to life in captivity and need special living conditions to thrive.

These include a tank size of at least 70 gallons; just ignore those who suggest that 40 gallons are enough. Maybe for a juvenile, they are, but not for an adult Gila.

These reptiles may be slow and less active than other lizards, but they still require sufficient space to remain calm and stress-free.

Even so, Gila monsters can still experience stress in captivity, despite all your best efforts. This is why they’re generally not recommended as pets.

If you think you can handle a Gila monster (which is possible with sufficient preparation and know-how), get ready to break at least $1,200 for one specimen and reach all the way up to $5,000.

This is without including the long-term costs associated with feeding, maintenance, veterinarian care, etc.


Gila monsters are, without a doubt, fascinating reptiles with unique physiologies and lifestyles. Many people love them for their looks, temperament, behavior, and long lifespans in captivity, but be wary.

These are venomous reptiles that have difficulties adapting to life in captivity. You can’t really pet them and caring for them requires serious efforts, both financially and time-wise.

However, you might be able to pull it off with a bit of dedication and some luck. In this case, you’ll have an awesome, venomous member joining your family for decades to come.

Robert from ReptileJam

Hey, I'm Robert, and I have a true passion for reptiles that began when I was just 10 years old. My parents bought me my first pet snake as a birthday present, which sparked my interest in learning more about them. read more...