Are you interested in learning more about iguana reproduction?
Or maybe you own a female iguana, and you’d like to know what to expect when she lays her eggs?
In this article, we’ll answer the question, “how many eggs does an iguana lay,” while also learning about the iguana’s gestation period and what to do to prepare your pet iguana for egg-laying.
Once they reach sexual maturity, female green iguanas lay around 20 to 70 eggs per year.
Although there are around 35 different iguana species (each with slightly different reproductive habits), we will be focusing on the green iguana, since this is the most widespread and well-known iguana in the Americas and the pet trade today.
Female green iguanas typically reach sexual maturity when they’re around 2 to 4 years of age, although some may mature earlier or later.
How Many Eggs Does an Iguana Lay?
Once they are sexually mature, iguanas reproduce annually until their deaths.
Green iguanas usually live 10-20 years in captivity, so for a female who reaches sexual maturity at age 3, lives to be 15 years old, and lays an average of 50 eggs per year, she will lay a whopping 600 eggs in her lifetime!
Iguanas mate annually, typically during the dry season to ensure their young hatch during the wet season.
After establishing their mating territories (conflict and fights between males are not uncommon during this stage), adult male iguanas are selected by females.
Female iguanas may court multiple males before choosing a mate, usually picking the larger males to mate with.
Six to eight weeks before and during the courtship period, male iguanas often take on bright orange or golden coloration, displaying their dominance.
Once females have selected and mated with a male, female iguanas take up residence in his territory.
Often one male mates with multiple females during the breeding season.
Remarkably, female iguanas can save sperm for several years, meaning she can fertilize eggs several years after mating.
In the wild, the breeding season usually occurs in late fall through spring, while in North America, captive green iguanas begin the breeding cycle from February through May, typically laying their eggs in June through August.
However, if conditions are favorable, they may breed at any time of the year.
Several weeks after mating, the female iguana selects and prepares a nesting site to lay her eggs in.
She creates a chamber by digging a burrow into the ground, and around 12 weeks (or 65 days) after mating, lays her eggs inside.
In the wild, female iguanas often travel miles to return to the same nesting spot year after year.
After laying her eggs, the iguana exits the burrow and fills it in, leaving only a small air pocket for the hatchlings.
Three to four months later, the baby iguanas hatch out of their eggs and dig to the surface of the ground, emerging as small but fully independent iguanas.
In the wild, only a small percentage of hatchlings will make it to maturity.
Can Iguanas Lay Eggs Without Mating?
This is a common question iguana owners ask, since many female iguanas rarely, if ever, interact with male iguanas in captivity.
So can your female iguana still lay eggs even if she hasn’t mated with a male?
Yes. Once your female reaches maturity (around age 3 to 4 years old), she will typically lay a hatch of eggs once a year, whether or not she has mated.
The only difference between these eggs and the ones laid after she has mated is they are not fertilized; therefore, no babies will hatch from them.
However, as mentioned before, female iguanas can store sperm in their bodies for several years, so if you purchased a female and have never mated her, but she mated before entering your home, there is the possibility she could release the sperm and fertilize her eggs.
How to Know If Your Iguana Is Ready to Lay Eggs
Loss of Appetite
About one month before laying her eggs (known as oviposition), the female iguana usually loses her appetite and only consumes a few sips of water and (if any food) some leafy greens or a bite of salad every day.
Why? The eggs grow so big (and there’s so many of them), she no longer has much room for or interest in food.
If your gravid female’s appetite has drastically decreased, don’t worry and don’t force-feed her!
It’s completely normal behavior and will not hurt her.
Visibly Large Abdomen
By the time your gravid female loses her appetite, she should have a swollen abdomen (although since she is not eating, it may not look much larger than normal, although it should feel tauter).
At this point, you may be able to see and (gently) feel individual eggs inside her.
If the eggs are visible and she hasn’t been eating for around four weeks, she is close to laying her eggs!
Burrowing and Nest-Making
Gravid female iguanas close to oviposition begin displaying specific nesting behaviors like digging deep holes, burrowing, and scratching the floor or bedding.
It’s important at this point to provide her with a suitable nesting box and burrowing materials, as the lack of an appropriate nesting place can sometimes cause egg-laying problems in captive gravid females.
What to Do If Your Iguana is Going to Lay Eggs
Gravidity (producing eggs) and egg-laying is a stressful time for female iguanas, so it’s important for you as the owner to provide her with a safe and healthy diet and environment, so she (and potential offspring) remain healthy throughout the process.
Maintain Her Temperature
During her gravidity and egg-laying time, her temperature needs to be kept at the higher end of her range (around 94° to 96° degrees Fahrenheit (34° – 36° C) for green iguanas).
Give Her Calcium
Iguanas always need plenty of calcium, but during the egg growing process, female iguanas need even more.
Boost her calcium intake by adding a little more calcium supplement (we like this one) to her food or administering the supplement more often.
- Highly bio-available source of calcium carbonate
- Free of harmful impurities (not from Oyster Shells)
- Safe levels of Vitamin D3
If she doesn’t receive enough calcium during the gestation period, her body will begin to take it from her bones to give to the eggs as they grow, meaning she could develop the metabolic bone disease.
It may be hard to give her plenty of calcium if she’s stopped eating.
In this case, you may consider administering a calcium supplement like NeoCalglucon daily.
Check with your vet to see if he can supply it.
Make Sure She Exercises
To ensure the egg-laying process is smooth, gravid female iguanas need as much exercise as they can get.
Make sure her enclosure is tall and wide and has lots of high branches and climbing apparatus for her to climb on, and if possible, you may consider giving her access to a small pool for swimming.
Give Her a Nesting Box
A suitable spot for burrowing and nesting stimulates oviposition (egg-laying) for gravid iguanas, so they need to have an appropriate nesting area in their enclosure.
To recreate a nesting area for her, place a large container inside her enclosure.
For larger iguanas, a rectangular outdoor trash can, laid on its side with the lid duct-taped shut and a hole cut in the upper lid for her to enter and exit will work, while for smaller iguanas you could duct tape two large kitty litter pans together to create a box, then cut an access hole in the upper pan.
Whatever your chosen box, make sure it is large enough, is completely enclosed, and has a large enough access hole for her (preferably near the top of the box).
You may even consider draping a cloth over the hole when she is laying her eggs to give her more privacy and reduce stress.
Once you’ve chosen and assembled your nesting box, you’ll need to fill it with a digging medium, like a thick mixture of sterile potting soil, sand, and a little water to keep it moist and dense.
Make sure the nesting box is in a warm and quiet environment like a closet or spare bedroom.
If you’re interested in iguana reproduction and have been trying to find out how many eggs do iguanas lay, we hope the information in this post was helpful and answered your questions.
And if your female iguana is getting ready to lay eggs, we hope you feel better equipped to care for her during this exciting time.