Best laid plans of Gilas and men..

Gila laying egg in hide box, which was moved to remove the egg.

This year started off with promise, but there was an asterisk overshadowing success. A total of twelve eggs were laid between two females (which has been the consistent average over the past few years, six eggs per female) which was good, and all appeared promising with blood rings in all eggs. The asterisk earlier mentioned comes from two factors; 1. I did not cool one of my adult males last year but still paired him with the females, 2. my main man Winston wasn’t too interested in the girls this year. I do not know if it was because I rotated my pairs, or “he was just not that into her” as the saying goes. Winston was only observed coplulating 3 times in 2021, versus 11 times in 2020. While I have hope for success this year, it is tinged in skepticism and truly illustrates how little we know about breeding Gila monsters in captivity.

Of course success can be had following “The Recipe” as beautifully laid out in Mark Seward’s book but, much like cooking, following a recipe gets the basic job done but does not give us the insight into the inner working of what is really going on.

Egg about one week after being laid, showing veins which indicates growth.

In spending years studying Heloderma suspectum; collecting articles, reading books, and joining and participating in online forums and Facebook groups, the realization that my success as a breeder has been a lucky coincidence came hard and fast this year. I would love to take credit for the success I have been fortunate enough to experience, but as stated in Jurassic Park I have simply taken what others have done successfully and applied it to my program. If it’s not broken why bother fixing it, right? If all eggs hatched and there were no issues, hard questions would probably not be asked. As this year has brought more failure than success (so far) it is hard not to face the fact there is much to learn. Since it is a universally known fact that Gila monsters are hard to breed in captivity, it seems this lack of knowledge goes well beyond my program.

Some of these eggs are bad, can you tell which ones? Here’s a hint, three are bad (insert sad emoji).

Another unfriendly first this year was an infestation of phorid flies in my Gila monster egg boxes. As this pest has not plagued me yet, it was unnerving to find maggots on dying / dead eggs, and some on good eggs. Did the phorid fly maggots cause the eggs to die, or were they simply drawn to the smell of the decomposing matter? From what I have gathered by speaking to other reptile breeders and checking forums, the maggots do not cause they egg to due, but I am not 100% sold on that answer. Before getting into that topic, it would be good to share what was done to get rid of the fly infestation.

Upon discovering the phorid flies and maggots on my Gila monster eggs (after a releasing a string of expletives that would make Anthony Bourdain blush), the best course of action in my mind was to sterilize the egg boxes (S.I.M containers) and medium (clay Pangea Hatch) and close up all holes in the egg boxes. S.I.M. containers do not come with any holes from the factory, so when I first received them four holes were burned with a soldering iron into the top of each side to allow for greater oxygen exchange. These were now sealed with electrical tape so as to not allow entrance of the flies to lay eggs. After sealing the holes, the boxes were sterilized. The Pangea Hatch clay substrate can be boiled to sterilize, which is what was done to ensure no fly eggs would hatch from this area. After everything was cleaned the Gila eggs were gently scrubbed with a soft toothbrush to remove any fly eggs and then put back in, egg box tops then sealed to prevent further entry. Since then I have not seen any fly or maggot activity, though I do open the boxes every two or three days to make sure of this as well as provide oxygen exchange.

I forgot to mention that one egg was separated from the rest as this egg has a “weak” spot. When the cleaning occurred this part of the egg was covered in maggots attacking this area. I assumed this egg was a goner and would be the next to die, but as of today this egg remains viable. The soft spot has since hardened and no further maggots have been found on the egg! It is my belief that if left in the container with maggots and flies, this soft area would have been continued to be exploited which would have further weakened the egg and eventually would have led to its demise. Of course without having a control specimen to compare it to, we will never know if this egg would have continued to survive or would have died but my money is on the death of the egg. Ultimately the hatching of this egg will be the determining factor of this experiment, so fingers crossed a beautiful Gila monster comes out later this year!

Bad egg being attacked by phorid fly maggots. Do the maggots harm good eggs in the same container?

With roughly 77 days until hatch, there is a lot that can happen. As my Grumbuach S84 keeps the temperature and humidity steady as a rock, I can only look at the other variables in my program for improvement. Every year new challenges arrive in breeding Gila monsters, and there is always something new to be learned. Unfortunately mistakes come at the cost of viable eggs and hatchlings, but there is always next year to make improvements!

Better together

With the discovery that hatchling Gila monsters over winter in their nest, I wanted to perform my own non-scientific social study of hatchling Gilas. Normally baby Gila monsters are reared on their own in solitary containers to facilitate easier feeding and maintenance, but this year I housed two siblings to see how they would be together. While they were housed alone for for the first two months to ensure both were feeding regularly and healthy, they were introduced into an adult-sized terrarium and have been there ever since. So far? The photo above best describes the behavior from the hatchlings. The definitely tend to share the same “burrow” / hide more often than not, and are active at the same time. Feeding has to be done carefully so as to ensure there is not fighting over food.

I do not know if there is a certain age they go their own way, but I will keep they together through the first year to see how they act with each other. Seeing this and the behavior of my adults makes me wonder about the social structure of these reptiles. There truly is still so much to learn about Gila monsters!

Check here for the scientific findings from the discovery above.

May 2021 Update: Nest boxes and hopefully eggs soon!

Momma getting ready for the big day!

Though work and the other parts of my life have kept me from updating this blog on a regular basis, working with the Gilas has not slowed down. As of today my females are gravid and have gone through their pre egg-laying shed so oviposition is expected within the next week, according to my calculations.

Two of my females cages with privacy tint installed.

This year my nesting protocol has changed due to the failures (or, opportunities for learning) of last year. last year one of my females delayed egg laying by about 10 days which resulted in the death of six viable eggs. Not a very fun lesson but certainly an opportunity for improvement. I think last year the female did not have the proper secure nesting area and held her eggs until she could not hold them any longer. I also tried a new nesting material which did not work out very well as it did not hold moisture for very long. This year, things have changed.

To help increase privacy and to solve the humidity issue everything has been changed. To start, the entire cage has been converted to a nest box. This is to allow the females to continue to thermoregulate (though over lower temperatures) throughout this period. I have installed privacy tint on 1/2 of the cage as well as a large black hiding box to increase privacy. I also went back to good old sphagnum moss misted daily to help maintain moisture in the cage. The ultimate goal is to provide a secure area that matches conditions for positive egg growth. So far it appears to be working as the conditions in the cage mirror those in my incubator (see below screenshot from my SensorPush app).

Pretty close!

Will this ultimately work? We will know within two weeks. If all goes well my females will lay viable eggs this year. If not, I’m sure there will be a lesson learned and opportunity for improvement next year! Fingers crossed!

2021 Gila monster breeding season is a-go!

Our 2021 Gila monster breeding season has kicked off and we could not be more excited! All pairs have been seen copulating and follicles appear to be nice and healthy. We hope to correct last year’s mistakes and improve our program through the insights gained over the past few seasons. We are also now incorporating the use of ultrasound (we’ll post more on this once we’ve actually figured this technology out). Stay tuned on the haps here at Goatsby’s Place and our amazing monsters, much more to come!

Great Gila article on

I always look for all things Gila on the internet and come across this fun and well-written article on of all places. Enjoy!

Don’t Call It a Monster

But be very cautious around the venomous, determined, lumbering Gila monster.

Constance CaseyApril 26, 20138:00 AM

We’re the ones with language, so we have the power to call one of our fellow vertebrates a monster. As lizards go, the Gila monster is unusually clunky, chunky, and large—not a lissome tropical creature like a gecko or chameleon. It’s not pretty, and it is venomous, a trait that inevitably complicates any relationship. Still, loathing the creature is irrational; being careful around it is not.

North America’s largest lizard gets the first part of its name from the Gila River, which runs through Arizona and New Mexico. Its habitat is the desert scrub and dry foothills of the Sonoran, Chihuahuan, and Mojave deserts. The creature is the subject of dozens of dread-inducing bits of folklore that are, at best, unverifiable. (Unlucky male camper in the desert wakes up to find a Gila monster chewing on some tender body part. Lizard spits venom in someone’s eye. Lizard springs several feet in the air to attack. Parachutist lands on lizard. Lizard’s foul breath can kill you.)

The creature’s lumbering form and sinister look play a part in popular culture. In The Treasure of Sierra Madre, for example, a Gila monster is part of a suspenseful ordeal for the character played by Humphrey Bogart. In Meet Me at the Morgue, a 1953 mystery by Ross MacDonald (a writer as good as Raymond Chandler), a sullen blonde says of her suitor, “Big offers he makes. Mink coat, a new car, a trip to Honolulu. I told him I’d sooner go with a Gila monster.” As part of the 1950s trend for enlarging animals to make them scarier, the creature is the subject of a 1959 B movie, The Giant Gila Monster. First victims? Necking teenagers.

Herpetologists, bless them, find the 2-foot-long, lumbering lizard fascinating and beautiful. Its body has bands of black alternating with the colors of an Arizona sunset –pink, buff, or orange. They hope that more knowledge will lead to less detestation, perhaps grudging respect. (One unexpected Gila monster fact is that a research scientist at a Bronx Veterans Affairs hospital found in the 1990s that something in Gila monster venom lowers plasma glucose to normal range in people with Type 2 diabetes. A synthesized version is now an ingredient in the widely used diabetes drug Byetta.)

Though the Gila monster is shy, and you should consider yourself lucky if you see one in the desert, there is certainly reason to be careful in its presence. Its bite is extremely painful, though very rarely fatal. Of the 5,000 or so known lizard species, the Gila monster (Heloderma suspectum) is among the few that are venomous. Another is its neighbor to the south, the Mexican beaded lizard (Heloderma horridum). (Note: “Beaded lizard” is a much better, less prejudicial choice for a name than “monster.” In both The Treasure of the Sierra Madreand The Giant Gila Monster, the lizard shown in the films is called a Gila monster but is actually a Mexican beaded lizard.) A few years ago, Australian researchers proposed that Indonesia’s infamous Komodo dragon could also deliver venom. (It was previously believed the dragon’s mouth was so full of muck that the victim died of a bacterial infection.)

The lizard’s species name comes from the Greek helos for stud, as in the head of a nail, derma for skin. The suspectum because the man who named it—paleontologist E.D. Cope, in 1869—at first only suspected that the lizard was venomous. It took another half-century to confirm it. With their studs they’re well armored, but a determined coyote can still rip one apart, and free-ranging cats often kill immature Gila monsters. A Gila monster can live up to 28 years; the most common cause of death, as more of the desert is paved, is being run over by a car. With a nonautomotive predator, the lizard’s first line of defense is to retreat. If cornered, it exhibits a repertoire of warning signals, including hissing and opening its mouth wide.

The nail-head look comes from osteoderms, bony beads embedded in the skin. Jan Johnson, an Arizona-Sonora Desert Museum curator who cares for 20 Gila monsters, says their hide feels like an exaggerated basketball. An X-ray shows, in addition to the usual spine and leg bones, an array of polka dots.

Careless handling, which Johnson does not engage in, is the usual cause of bites. The vast majority of verifiable recorded bites (about 150 in the past 60 years) are on the finger or hand, delivered by a pet whose apparent passivity lulled its owner into handling the creature, or by a wild Gila monster avoiding capture. (Collecting Gila monsters in the wild is against the law.) Some of the bites occurred during a demonstration in a classroom or lecture, which has to have been deeply embarrassing as well as painful. Inebriation is often involved. There’s a verified story of a man in a bar bitten while playing a kind of Russian roulette by reptile, repeatedly sticking a finger into the animal’s mouth.

The last recorded fatality was in Casa Grande, Ariz., in 1930. As reported in the Arizona Republic, “Tom Reap, 62 years old, proprietor of the Moore pool hall, died at 12:20 o’clock this noon in the Casa Grande hospital, two hours after he had been bitten by a Gila monster.” The story continues with useful information about what not to do with a venomous lizard. “Mr. Reap was playing with the animal in the pool hall when he was bitten. The animal had been brought into the hall by one of the patrons and several were standing around looking it over and discussing it when Mr. Reap appeared. He began tapping it on the nose, witnesses said, and upon being cautioned replied: `Oh, it wouldn’t hurt you even if it did bite.’ ”

Reportedly it took a helpful pool hall patron five minutes, using a pair of pliers, to detach the lizard from Mr. Reap.

Which brings us to the Gila monster’s venom delivery mode. The creature is loath to use its ultimate weapon, but once deployed the system is absolutely terrifying. The Gila monster is the pit bull of reptiles. Its short, sturdy skull with blunt, black snout is adapted to a long bite. (The shape works; it hasn’t changed much in the past 23 million years.) Venomous snakes by contrast have fragile skulls, built to conform to the shape of whatever they’re eating, often something bigger than they are. Snake venom is injected, hypodermic-style, through fangs in the front of the mouth, and it acts quickly. The point is to subdue prey before its thrashing injures the snake.

If you are so astoundingly foolish or unfortunate as to be bitten by a Gila monster, it will get a good grip and then chew; it can hold on for as long as 15 minutes. The grinding releases venom from glands into grooves in its sharply tipped teeth. (All venom, incidentally, is modified saliva.) Oddly and inefficiently, the two glands are located near the bottom teeth, and the poison must travel upward, presumably by capillary action.

The longer the bite, the more venom enters the victim’s body, via lacerations made by the teeth. One emergency medicine handbook provides “tips and tricks” for removing the animal. These include the following: Don’t pull or pry it off; that increases the possibility of leaving teeth in the wound. A flame under the jaw or immersion in water may work.

In addition, there’s this rather considerate advice: “Put the animal’s feet on the ground so it doesn’t fear falling.” And a particularly ominous note: “Always take special care to prevent reattachment of the animal to the victim or subsequent attachment to the person removing the animal.” Doctors are advised when cleaning the wound to make sure all the teeth are removed.

The effect of the venom, potent but not as damaging as a rattlesnake’s, is excruciating pain that has been described as a steady burning, like a spine embedded in the flesh, lasting up to 24 hours. There’s no commercially available antivenin; doctors treat pain and swelling and the most dangerous possible effect, a drastic lowering of blood pressure.

Gila monsters use their venom sparingly and primarily as defense against predators rather than to subdue prey. (Their fellows in using venom primarily for defense are the platypus and the stonefish.) Daniel D. Beck, author of Biology of Gila Monsters and Beaded Lizards, says he has often seen Gila monsters “delicately swallow” young cottontails without the chewing or pumping that’s displayed when they envenomate an enemy. The lizards’ favored foods are bird and reptile eggs, newborn small mammals, and bird nestlings—food sources that do not put up much of a fight. Eggs seem to be their favorite; the lizard splits the egg and, kittenlike, laps up the yolk. A Gila monster can eat one-third of its body mass at one sitting and survive on three good meals a year.

Because they don’t go out foraging often and they stay in a cool place in the summer, you’d be fortunate to see a Gila monster in the wild, Beck says. “You’d have to be a fool to be bitten,” says Beck, who has not suffered a bite. A Gila monster spends 95 percent of its time in a burrow, out of the sun, venturing out mostly in spring to find food and a mate.

Like everything that lives, Gila monsters are driven by hunger, fear, and the need to reproduce. What looks sinister and snakelike—the forked tongue flicking out every few seconds—is the lizard’s way of experiencing the world. The Gila monster is essentially tasting the air, picking up clues as to where there might be some quail eggs to eat, a likely mate, or a coyote to avoid. When the lizard’s tongue pulls back in, the two tips are inserted into little holes in the roof of the mouth. This delivers the captured odor particles to the Jacobson’s organ, named for 19th-century Danish anatomist Ludvig Levin Jacobson. Some of the chemical compounds bind to receptor molecules, sending messages to the lizard’s brain. Other reptiles have the Jacobson’s organ, as do some amphibians and mammals.

The Gila monster evolved such a keen sense of smell because food in an arid environment is widely distributed. The creature rarely runs, but it can trudge for miles. Most people’s impression of Gila monsters, from seeing overfed specimens in a zoo, is that they’re obese and lethargic. Smaller lizard species, in contrast, are in danger of being eaten and adapted by being well camouflaged or very fast. (And there’s their amazing ability to drop the tail when threatened. The severed tail continues to twitch, keeping a predator’s attention.)

The Gila monster does not give up its tail, which is as useful a camel’s hump for fat and water storage. In times of scarcity, the tail shrinks down to something like a ballpoint pen rather than the usual kielbasa sausage.

Low metabolism and frugal energy use are advantages in food-scarce regions. But recently it has been found that though they have a low metabolic rate, Gila monsters possess high aerobic capacity and surprising endurance.

Beck demonstrated this by putting a Gila monster on a rubber treadmill with a Dixie cup over its head. A tube from the cup sends the lizard’s exhalations to a gas analyzer and calculates the rate of oxygen consumption. How does a Gila monster respond to this gymlike activity? Some object, Beck says, but most keep on tramping “in a kind of trance. Into the Zen of being a lizard.”

In the wild, Beck tracks the lizards’ long routes by radio transmitters implanted surgically (with difficulty because of the studded skin). He and other scientists have found, by using radio telemetry, that a lizard is loyal to a couple of particular shelters. Sensibly, they find a south-facing haven in winter, one that’s cooler and moister in the summer.

Beck loves them, but when asked what a Gila monster’s life is like he has to say “dull.” They do spend most of their time doing nothing. However, from April to June, there is drama, ritual combat that’s a challenging endurance test. Two males meet in what is essentially a wrestling match, arching and flexing sumo-fashion. The contest, which can go on for hours, ends when one has forced his opponent to the ground and remains on top. Though equipped with venom and sharp claws, the males, sensibly, do not kill or wound each other. The loser walks away unscathed; the winner, having proved his fitness to reproduce, gets breeding territory or, better, a shelter with a female inside.

When a female has been won, the victorious male lies beside her and rubs his chin on her back and neck. If she accepts him, she raises her tail and the male moves his tail under hers, bringing their vents into contact. Copulation lasts from half an hour to an hour. Which brings us to the hemipenis. Like snakes and other lizards, a male Gila monster has a retractable penis that pops out like the finger of an inflatable glove, an advantage on rocky soil. Actually, he has two; they pop out together but only one at a time is used. The hemipenises are elongated tubular structures stored in the tail, decorated with tubercles in a fashion Beck calls “flounced ornamentation.”

In July or August, the female lays one to 12 eggs in an underground hole. Incubation may last nearly 10 months, and the 4-inch-long young may not emerge until a year after insemination.

For millions of years, human beings figured very little in Gila monsters’ quiet lizard lives. Then we began building deep into the desert. One of Beck’s formerly prime locations for studying Gila monsters is St. George, Utah, now the site of a fast-growing retirement community. (Someone in one of those newly built units probably has a bottle of Byetta in the medicine cabinet.) Desert houses, surrounded by irrigated land, provide attractively moist, shady environments for the bolder lizards, which is beginning to create a problem. Every year dozens of Gila monsters (and thousands of rattlesnakes) are removed from properties in Phoenix and Tucson. From the homeowner’s point of view, the lizard is large and scary—and protected by state law; killing it is not a legal option. From the herpetologists’ point of view, there are too many Gila monsters run over by cars and too little unpaved, unspoiled desert habitat left for them.

Beck, who grew up exploring deserts in his native Utah, allows that the Gila monster doesn’t seem beautiful to most people, “But they’re an indication that we live in a beautiful place. Lose them and the beauty is diminished.”

2021 Season Update

It’s mid-February, the adult Gilas are slowly coming out of hibernation, the 2020 babies are going to new homes, and to say we are excited about the 2021 season is an understatement! This year we have an ultrasound that will help us improve breeding and oviposition, and we will share some information on this here once we can successfully figure it out:$ If you are interested in getting on the list for 2021 or just want to discuss monster, drop us a message!

In case you haven’t seen them, here are 2020’s babies!

The Honeymoon Suite

Which one is the boy and which is the girl? Guess first, then answer below.

My 2020 Gila monster season is off and running. After reviewing my data and re-reading my Gila books, I was going to wait until after April 1 this year to pair the Gilas as that is when the magic happened (and seems to be for others as well). With the Shelter-in-Place order in full effect I got bored and but them together last weekend, and guess what? No activity yet. What I have found interesting is that the Gilas seem to remember each other from last year and there was no fighting between the pairs (females bit males for being too pushy). This year they are much more chill, and are spending time together the hide boxes. I have been checking in at night to see what is going on and while both Gilas are active, copulation has not yet been observed. Being a Nervous Nelly, I am concerned that they will not breed this year but will hold my real worry for late April

Belle & Pink Floyd (banded Gila monsters) resting sweetly in their hide cave

To me, the real question is could Gila monsters mate for life? I’ve read that in the wild males go back to the same shelters where they have previously copulated and in my observations females certainly do prefer some males over others. The way they rest together and spend time with each other makes this is an interesting avenue to explore. Some breeders swap different females in male cages and have great success, but I am going to try leaving known pairs together to see how things go. I can see why having one pair of Gilas could be difficult to breed and that groups (3.3 or greater) are suggested.

Winston & Heather (reticulated Gila monsters) snooze the day away

As with all things, time will tell. New observations, and hopefully some activity, will be reported here. Stay tuned..

Answer: Male on left, female on right:)

adidas Harden Vol 4 Gila monster shoes

Earlier this year adidas in collaboration with famed basketball player James Harden released Vol. 4 of his namesake shoe. Why is sneaker news on a Gila monster website? Because a variant of the shoes are Gila monster pattern! And they are quite a match with our beloved venomous lizard’s intricate pattern. Previously, a Vol. 1 shoe was also called Gila monster pattern but they were similar colors and not patterned the same so not of real interest to me. But when these cam out, I knew a pair had to be mine! I haven’t played basketball in decades, but maybe I can wear them the Gila room to blend in a bit better:) Get yours here from adidas while you can, they seem to sell out fast!

2020 Gila monster breeding season begins!

With the babies I’ve held back are growing like weeds and coloring up beautifully, I’ve taken the adults out of brumation and am warming them up and will be feeding them their first meal soon. I’m both excited and nervous as to how this season will turn out. Will all the eggs paid be fertile? Will all the fertile eggs go to term? An educated guess says no to both but if improvements are made I am moving in the right direction.

I’ll be doing some new things this year. First, I’ll be pairing straight reticulated with reticulated, and banded with banded. Also, instead of leaving switching males between cages I will keep one male with one female for the duration of the breeding season. The females do seem to have preferences, and hopefully they still lie each other this year. I am waiting until the last week of March to start pairing as last year the females were not receptive and often attacked and bit the unrelenting males so it would be nice to avoid this drama and potential injury. I’ll keep everyone posted on the progress and of any successes and failures on my second year of breeding these amazing Gila monsters!