Photo by Vince Pinto

Among the entire fauna of planet Earth that crawl, swim, fly, and pounce, a mere handful of species have inspired true fear among Homo sapiens. Large cats, bears, sharks, crocodiles, venomous snakes, spiders…and, yes, Gila monsters. You might look no further than the fact that few of its fear-mongering cohorts have their own B-movie. “The Giant Gila Monster” is a forgettable 1959 flick that merely serves to reinforce the terror that this often-misunderstood species evokes. What, then, is the truth about this unique southwestern lizard?

First of all, size does matter when it comes to these issues. For the record, a two-foot Gila monster weighing up to, and occasionally over, five pounds is a truly behemoth one. There is no way for a Gila monster to consume a human. 

Still, in a world seeking superlatives, the monster is the largest and heaviest lizard in the U.S. On the other hand, South America, Asia, Africa, and Australia all boast much larger lizard species, to put things in perspective. If you’re searching for a “man-eating” lizard, then you must travel to Indonesia, where a lurking Komodo dragon might fill the bill nicely. 

This striking species does, however, harbor a potent venom and is quite capable of inflicting a memorably painful bight on foolhardy or unlucky people. The former consist of those folks who insist on picking up wildlife, thereby courting the bulldog-like bite of this otherwise placid creature. I have perhaps encountered 15 Gila Monsters in the wild and none of them remotely menaced me in any way, shape or form. They all went about their business of foraging and/or slowly walked away from me. Humans who are bit experience excruciating pain via the venom, which fortunately is not considered fatal to healthy adults. 

While Gila Monster venom is almost as potent as that of a western diamondback, very little is produced in comparison to its reptilian cousin. Further, Gila monsters must chew their venom into the wound with grooved teeth, lacking the hollow fangs found in many venomous snakes.

Gila monsters have long been the victims of myths. One popular tall tale held that their breath was toxic. Others went to size, claiming weights such as 35 pounds. The bite was often considered fatal.

Gila monsters feed largely on bird and reptile eggs with small mammals, nestling birds, insects and carrion rounding out the diet. Occasionally they climb trees in search of bird nests and eggs. In this regard they play second fiddle to their larger cousins, the Mexican beaded lizard found south of the border. 

Much like an anaconda or a shark, Gila monsters can thrive on relatively few meals each year. Their slow metabolism and large periods of inactivity are conducive to this feast or famine feeding mode. In fact, monsters may spend about 90% of their time relatively inactive in an underground lair, where they bide their time saving calories. 

They can be found day or night, depending upon temperatures and prey activity, any time of year, though particularly from May through September.

Having secured ample calories, intrepid male monsters search for mates by scent and sometimes after ritual combat, which can determine male dominance in a female’s territory. Females select a mate likely based on size, vigor, and perhaps color pattern. 

Gila monsters sport a broad spectrum of skin designs and colors, reflecting genetic diversity over their southwestern range. The same beaded/mottled orange and black or yellow and black skin pattern helps to hide them from the inquisitive eyes of large predators or rambling humans. This is just as well, since prying eyes may lead to prying jaws biting the less astute bipeds of the world! 

Vincent Pinto and his wife, Claudia, run RAVENS-WAY WILD JOURNEYS LLC, their Nature Adventure & Conservation organization devoted to protecting and promoting the unique biodiversity of the Sky Islands region. Visit: www.ravensnatureschool.org