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Everything You Need to Know About the Gila Monster

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Amara is a blogger and writer. She is a graduate in life sciences and has a master's in social sciences.

Gila Monster, Photo credit; Pixabay

Gila Monster, Photo credit; Pixabay

Found in the Mojave, Sonoran, and Chihuahuan deserts of the southwestern United States and northwestern Mexico, the Gila monster is a black lizard marked with dramatic patterns of yellow, orange, or pink. This lizard was named after Arizona's Gila River basin, where it was first discovered.

Scientific Classification

  • Binomial name: Heloderma suspectum
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Squamata
  • Family: Helodermatidae
  • Genus: Heloderma
  • Species: H. suspectum


The study of this subject has been around since the age of the dinosaurs. The Gila monster is the nation's largest lizard, with a length of up to two feet (24 inches) and weighing in at more than five pounds. It is also the only poisonous lizard of New Mexico.

Life Span

This creature has an average life span of 20 years in wild. In captivity, the Gila monster can live up to 35 years. It is now considered a threatened species as its population is shrinking due to human infringement.


They generally inhabit desert scrubs, succulent desert, and oak woodland. They can be found in burrows, thickets, and under rocks in locations with a favorable micro-climate and adequate humidity. This is so that they can escape the heat of the day. They can be observed in puddles of water after a summer rain for water resources, but they avoid living in open areas such as flat places and open grasslands.


Gilas are sluggish in nature and primarily feed on new born mammals, lizards, frogs, birds, insects, and eggs of other animals. They primarily hunt by their sense of smell and taste. The lizards have been observed invading rabbit burrows and swallowing baby rabbits whole. They can eat four rabbits in a single meal. Such a meal can provide a Gila monster with nearly half of its nutritional requirements. Unused energy is stored in the large tail and drawn on as needed. A fat tail is an indication of a well nourished Gila monster.

Potent Venom

The lizard produces venom when it bites down. Biting compresses poison glands in the reptile's lower jaw and triggers them. The glands then release toxins when the lizard bites a victim. As a Gila bites its prey, its venom flows into bite wounds. Its venom creates an intense pain that acts on the nervous system. Its pain can be felt like a wave of fire, and it may end in severe shock.

However, there are no medical records of any human fatality from such bites. They are venomous, but due to their sluggish nature, they are generally not dangerous. They are rarely a real threat to humans.

In these recent years, scientists have learned more about Gila monster, and how they use their venom. They concluded that it is used for defense purposes against coyotes, hawks, and owls, and not for predation.

A thick, fat tail means, a well nourished Gila Monster. Photo credit; Pixabay

A thick, fat tail means, a well nourished Gila Monster. Photo credit; Pixabay

Incredible Sense of Smelling

The Gila monster has an incredible sense of smell. They flick their tongue to pick up scent particles in air and ground. That helps the animal to reach its food, including baby birds, small mammals, and eggs. Its incredible sense of smell can find eggs buried 15 centimeters or 6 inches deep. Their sharp claws help them to dig up the meal.

Metabolic Mysteries

Scientists has been fascinated by the Gila's metabolic abilities, as the lizard can survive on so few meals. From the lab experiments, they learned that these reptiles have an unusually low metabolism rate.

Since 1983, a team of scientists have implanted radio transmitters in the abdominal cavities of wild Gila monsters. Through ample laboratory measurements, and signals from radio transmitters, they learned that the animal's metabolic rate decreases at lower body temperatures, thereby reducing food needs. It means "that Gila monster can spend up to 95 percent of their lives underground and not have to spend a whole lot of time searching for food."

The reptile has an unusual aerobic capacity, an ability to take in huge quantities of oxygen that would come handy for heavy breathing under adverse condition. However, it puzzled scientist that why else might the creature need such a huge capacity? Does it play a key role in reproduction?

What happens to the metabolic rates, for example, of males fighting over females, in mating season? Males do fight for mating, and their fights are strenuous. Only after hours of hissing, snorting, and biting, a winner emerges.

Through a number of lab experiments they concluded that, Gila monster have, "in fact the highest aerobic capacity of any American lizard," and more specifically, "its the male with the highest aerobic capacity that wins amorous contest."


After many days of combat, the winning male is typically joined by a female. In captivity, copulation has been observed to last from 15 minutes to two and a half hours. In the month of July, the female lays about six eggs, usually at abandoned nests of pack rats. Young hatch the following month of May. Gila monsters emerge from their eggs active, completely formed, and essentially self-sufficient. The young receive virtually no attention from their parents.

Trading and Tracking

One of the issue Gila monsters face is the illegal pet trade. Because the creatures are incredible preservation pieces, black-market profiteering involving the reptile has now grown so much.

Some collectors interested in Gila monsters as exotic pets have paid as much as $2,100 for one animal. And the fact is that only Arizona, New Mexico, California, Utah, and Nevada legally protect Gila monsters. Illegal collectors of Gila's cannot be arrested, once these animals are taken beyond the borders of these states.


This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Amara


Amara (author) from Pakistan on March 30, 2021:

Wow Manatita, I think you also had some incredible senses when you were a child.. Thank you very much for reading it.. I am glad that you found it interesting.. Salam.. Allah bless you..

manatita44 from london on March 30, 2021:

Sad that they are taken away by illegal collectors. They have powerful scents! When I was a child I could tell where the crabs were hiding in the sand and would dig them up.

Very interesting info about these Gida Monsters. Perhaps I can live 200 years if I slow my metabolic rate. I think Yogis do that. Peace.

Amara (author) from Pakistan on March 30, 2021:

Thank you so much Misbah, I am glad to know that you found it informative.. Stay blessed my sister..

Misbah Sheikh from — This Existence Is Only an Illusion on March 30, 2021:

Amara, it was an interesting and informative read, I didn't know that much about Gila Monster before.

Thanks for sharing

Blessings :)

Amara (author) from Pakistan on March 30, 2021:

Thank you so much Ann, I am glad to know that you liked it.. Have a wonderful day.. God bless you and protect you..

Ann Carr from SW England on March 30, 2021:

What a strange, fascinating animal! Thanks for the education.