Over the past few years successfully breeding Gila monsters I have seen an interesting behavior that is fascinating; nest box guarding! Each year after laying eggs my females back fill the nest boxes and then vigorously defend the nest. I cannot re-connect the cages with the males for at least a month after oviposition! The moms get extremely aggressive and if I put my hand in to grab or move something they run over to attack.
I am curious how this works in the wild as it’s obviously an innate behavior, but with wild Gila monsters breeding habits virtually unknown to us it may be some time before we know the answer.
Once the female Gila monster backfills the nest I know viable egg laying is over (I also check on ultrasound to be sure). Some slugs can still be laid after the nest is filled, but they are most certainly bad.
I how in the future we can piece the puzzle together between wild and captive behaviors and shed more light into the secret lives of Gila monsters!
Yesterday one of our females laid her first egg of the 2026 Gila monster (Heloderma suspectum) breeding season, followed up by two more females laying today! There are still more to come but the excitement is growing! So far only three slugs out of 13 eggs, but I do expect a few others to turn over the next few weeks. Stay tuned for more posts and updates!
The pre egg-laying shed (what I calls PELS) is a sure signthings are progressing reproductively inside the female. This shed is different from any other – the pieces come off in large bits whereas it is usually small chunks over a period of 10 days or so during a regular shed. I ultrasound every few days to keep an eye on the progression and keep detailed notes to try and anticipate egg laying. PELS occurs after ovulation and sends me a visual signal to get things ready for oviposition. Nest boxes ready? Check. Incubator set up? Check. The hopes and dreams of getting lucky enough to seeing a baby Gila hatch this year? Check, check, double check!!! Two of the five females we are breeding this year are deep in PELS (Belle and Heather pictured here), two more are starting (Misty and Paisley) and the last is just starting to ovulate (Lucy). Fingers crossed for another great year here at Goatsby’s Place and to all my friends breeding Gila monsters! Here’s to an amazing 2026!
This was a cool find from May 2025 Herpetological Review I picked up while doing my daily scour for new Gila info. Gilas are so secretive it’s a wonder we can get them to breed in captivity with all the activity and interaction they have with their keepers! There’s also a related video which may be NSFW (but in a scientific way) which I will link below. I think my life would feel pretty fulfilled if I got to trail Gilas in the wild for research.
The end of our 2025 Gila monster breeding season came to an end this week when Gila 62 fully emerged from the egg! Ten eggs made it all the way and I could not be happier with the results! Two new moms (Misty and Lucy) produced their first viable hatchlings and stalwarts Belle and Heather did not disappoint. Above are the babies born this year and it is interesting to see what the pairings have produced over the years.
Can you see the hyper-pink one?
As with every season there were wins, losses, and lessons learned. I feel lucky and proud to have been successful another year breeding Gila monsters. We have a just a few babies are still available as of this post so drop us a line if you see something you like! And our 2026 waitlist has already started so jump on now especially if you are looking for a hyper-pink or aberrant (or both traits together as we had this year!). A few photos from the season for your viewing pleasure below!
The anticipation is killing me. So close to hatch time for our 2025 Gila monster babies it’s hard not to check multiple times a day! with this years pairings it will be a very interesting year to see what pops out! Hopefully some high pink reduced pattern Gilas pop out, but no matter what they’ll be beautiful baby Gilas to enjoy! Stay tuned!
Our 2024 holdback is getting more beautiful with age!
Hey Monster Squad! It’s been way too long since I last sent an update out which is disappointing as so much has happened since the last post. As with all Gila monster breeding seasons, this one was full of surprises and a lot of lessons to be learned.
Caught in the act.Well, we know what this is..Locked up at night.
First, during pairing and copulating we attempted a 1.1 ratio for breeding pairs which we hoped would increase success. Two of our previously bred females were seen copulating at least five times, but the new girl we got last year was only seen once. Eggs seem to be maturing well as monitored on ultrasound, except for the new female which only had two eggs (the other two females had greater than five eggs from what we could see). By the time egg laying came about in June this is where things change and deficiencies in our program were found. our two long-term females produce 13 eggs between the two of them, and the new girl produced two.
Egg forming from follicle as seen by ultrasound. Egg at a later stage, the shell now visible on ultrasound. Momma monster made a nest for her tightly buried eggs and guarded the nest for over two weeks!
Unfortunately only four of the 15 eggs survived of the whole group to date. One was actually eaten by it mother! This was a severe disappointment but valuable lessons were learned. First, the new female was under condition and not ready to be bred but she had enough weight and we thought she would be ready, she was not. Second our egg-laying protocol needs to be revised as it appears our girls are not comfortable laying eggs in their current egg boxes, which at this time are the entire cage turned into an egg laying nest with dark tint over the glass to provide privacy. Unfortunately this is not enough and we are going to try something entirely new next year fingers crossed!
Inside the nest above, six Gila monster eggs!Bad eggs and good eggs, wish I had Willy Wonka’s machine to save some time.
As we approach the end of October we have four eggs still in the running. Four out of 15 is not a good ratio but some success is certainly better than none at all! It’s interesting that most eggs go bad within the first 30 days of laying, which says to me that our incubation protocol technique is working. Of course mid and late term and losses have happened but generally most eggs even fertile they are doomed will go bad within the first 30 days. These days I’m checking the incubator daily opening to egg boxes for fresh air as the humidity and temperature continue to remain stable throughout the week incubation period. We are super excited for the birth of our baby Gila monsters – each time I truly feel like a kid during Christmas opening the big gift center left under the tree! As soon as the babies are out we will post pictures and contact those on the waitlist in the order that they joined (Allen you’re up first!).
Late-season candling of a viable egg showing nicely growing veins.
So as we wrap up our 2022 Gila monster breeding season and get our monsters ready for the Big Chill (hibernation, not the movie), we look forward to an amazing 2023 breeding season. One of our 2019 females produced here is growing follicles as shown by ultrasound and will be attempted to be bred next year. We are also very excited to have our axanthic Gila monster Winnie up to condition and ready to breed next year. This is a very, very exciting project for us as few of these morph are being bred throughout the world. We are also excited to put into motion the lessons we learned in this and past seasons to improve our success and to see more amazing baby Gila monsters born into this world, because what world isn’t better with more Gila monsters in it?
Winnie, our axthanic Gila, looking to be in good condition
Kicking off the 2022 Gila monster breeding season seemed like a time to start our YouTube videos. We plan on documenting the entire breeding season, from warm up to hatching babies, to help expand the knowledge of breeding Gila monsters in captivity. Check it out here and let us know what you think!
The 2021 baby Gila monsters are all out and settling in here at Goatsby’s Place! We are very proud of our beautiful baby monsters, and feel blessed to have been successful again this year. While most are spoken for, we may have a few available for new homes. Please email us if interested, or to get on the list for 2022.
Goatsby's Place 