How Do Box Turtles Reproduce?

Are you thinking about reproducing or breeding box turtles?

It’s a natural extension to the love of owning one of these pets, but you need to be careful about how it works and understand what you’re getting into. 

This article is here to help you come to breeding better prepared. 

How Do Box Turtles Reproduce?

Once box turtles in the wild have reached sexual maturity, they will mate in spring, after waking up from their fall-winter brumation. Females will then lay their eggs in late spring or early summer.

Sources differ on when box turtles reach sexual maturity. 

It will depend on several factors, including overall health, available food, and the environment. 

Answers for when an individual will be ready to mate range from 4 to 20 years of age.

Mating requires a male to meet a female. 

Individual turtle ranges may be as large as a football field but, for various reasons, have no turtles of the opposite sex. 

For some turtles, the search begins after a rainfall event. 

Turtles rarely vocalize or call, but they often will find a mate or while mating. 

They will also track each other via scent. 

There is no guarantee two turtles of opposite sexes will meet every spring. 

If they meet each other later in the year, they might mate regardless of timing.

March and April are the busiest months for courtship, fights, and mating. 

Males fight each other over females by shoving, flipping each other over, butting into each other, and biting. 

Usually, turtles are sociable with each other and not aggressive. 

Mating season is one of the rare times you will see aggression between turtles.

Once the male has won his right to mate with the female, the courtship begins.

He will circle the female and bite at her carapace. 

Eventually, he will get into position by gripping the hind part of her shell with his back feet. 

If the female is receptive, she will usually help him with her hind legs. 

Male box turtles have long penises, which help them reach the female’s cloacal vent underneath her body. 

He will lean back, almost vertical, once he is in.

After mating, turtles do not generally stick together. 

A female can store a male’s sperm inside her for up to four years before fertilizing her eggs with it. 

This is especially helpful, considering there is no guarantee turtles will be able to mate every year.

Box Turtle Eggs And Hatchlings

The average clutch size for a box turtle is about 4-6 eggs. 

In most habitats between May and June, a mother box turtle will dig a hole in sandy or loamy soil, lay her eggs in it, and then bury them. 

She may also use abandoned mammal burrows for this purpose. 

A turtle living in a hotter environment, usually in the Southern United States or in Mexico, may have two clutches in a single season. 

Once the eggs are buried, the mother turtle leaves her eggs and her hatchlings to fend for themselves.

Incubation takes 70-90 days. 

The hole’s ambient temperature will determine the sex of the hatchlings since they don’t have sex-determining genes like humans. 

This phenomenon is called Temperature-Dependent Sex Determination. 

Within the appropriate range, temperatures on the higher end of the scale will result in female hatchlings, while lower temperatures will result in male hatchlings. 

Mid-range temperatures provide a 50-50 shot of getting either sex.

When they are in the egg, turtle embryos are attached to yolk sacs by a cord. 

The yolk sac provides enough nutrition to sustain them through incubation and even for several weeks after hatching. 

Like chickens, turtles have an egg tooth, which helps them break through their eggs before falling off.

Baby turtles are especially vulnerable to predators and will be until they reach adulthood, anywhere from 7-10 years of age.

 Their shells and carapaces have not yet fully hardened to provide them with the defense they need. 

The hinges which will let them fully retreat into their shells as a defense will not function until they reach adulthood, either.

In general, baby box turtles also have higher protein needs than adults. 

Babies usually spend much of their lives in water, where insects, slugs, and snails are more plentiful. 

As they age, they will shift to spending more time on land and eating more vegetation.

If they live into adulthood, a turtle may have a life expectancy of 50 or even 100 years, though the average age is 25-35. 

If you keep them well in captivity, they should live a long time too.

How Do I Breed My Box Turtles?

Breeding box turtles could be a fun and profitable hobby for you. 

However, there are a few things you will need to know before starting.

First, check the animal regulations in your area, usually from the Department of Natural Resources. 

Most of North America has protections and regulations in place for box turtles, both wild and captive. 

Depending on where you live, your state or local government may prevent the captive breeding of box turtles. 

Second, breeding is a stressful process for many turtles. 

Only the strongest and healthiest pairs should be mating with each other. 

Make sure you have kept your intended breeding pair for a few years before letting them mate, and make sure to take your breeding pair to the vet before mating to ensure they are in their best health. 

Do not breed a turtle with a damaged shell.

Letting a sick female turtle breed may be especially dangerous and deadly. 

If your turtle has a condition which makes her keep her eggs in her body instead of laying them, it may cause her death. 

Other conditions may affect the eggshell thickness, resulting in eggs which may not survive outside of their mother.

Breeding siblings with each other or parents with their children may result in undesirable genetic anomalies. 

While some box turtle species can cross-breed with each other, these specimens may also possess genetic anomalies. 

If you are planning on breeding for profit, it is essential to minimize genetic mutations. 

If not, still avoid incestuous breedings and cross-breeding as the hatchlings may develop health issues.

Make sure you know how to raise and care for hatchling turtles before breeding. 

Hatchling turtles, even in captivity, are especially vulnerable. 

Ensure you have a proper plan in place for when they are old enough to be sold or adopted out. 

Do not just give them away to potentially unsuitable pet keepers. 

You want to ensure the best life possible for any new life you create. 

This involves knowing whoever you entrust care to knows how best to take care of a pet turtle.

Never release captive-bred box turtles into the wild. 

Most states have laws in place against captive-bred release since so many native populations are currently in decline. 

Turtles can carry diseases and illnesses to each other, which taxes already vulnerable native populations.

Sometimes, your box turtles will breed and lay eggs without your knowledge or intention. 

If this happens, do your best to take care of the eggs while incubating and the hatchlings after birth.

Intentional Brumation

While you do not usually need to brumate your captive turtle, most reptile experts recommend an intentional cooling period before intentionally breeding your turtles. 

The change back to their normal temperatures in spring should stimulate mating behavior. 

Hibernation comes with its risks, so make sure your turtles are in good health with a veterinarian.

Before hibernation, feed your breeding turtles foods high in vitamin A. 

These include broccoli, collard and dandelion greens, squash, carrots, pinkie mice, and fish. 

Increase fiber content at the end of summer with additions of timothy hay, alfalfa, weeds, and safe grasses.

Build an insulated hibernation box.

This could be as simple as placing two boxes inside each other with an insulating layer of newspaper in between. 

Make sure it is big enough for your turtle to turn around in.

Fast your turtles 10-14 days before hibernation begins, keeping them hydrated with soaks in tepid water. 

Weigh your turtle and record it. 

Every week during hibernation, weigh them to make sure they are not losing too much weight. 

Keep a clean drinking water source in the enclosure or hibernation box since reptiles will occasionally wake up to drink water during their hibernations.

Keep in mind hibernation may not be safe, even for healthy and strong adult turtles. 

Some species, like the Florida and Gulf Coast box turtle, may not hibernate at all.

Taking Care Of Moms And Hatchlings

Once your turtles have successfully mated, the female will need her solitary enclosure. 

Set one up with all the things she’s going to need plus multiple areas with soil at least 8″ inches (20 cm) deep for egg-laying.

 A mother box turtle will usually pick a sunny, humid spot next to rocks or logs. 

It’s a good idea to replicate this as closely as possible. 

Keep her in the enclosure from May to July.

It may be difficult to tell when she has laid her eggs since she will bury them. 

However, it is better not to disturb her too often during the egg-laying process. 

Limit your visits to occasional checkups so as not to stress her out.

If your turtle has laid her eggs above ground or in her water, this is a sign the eggs are infertile. 

Female turtles will usually deposit clutches which won’t hatch in water or on the ground instead of burying them.

Once she has laid eggs, put a wire mesh cover over the burial spot to protect it. 

It is best not to move the eggs into a separate incubator once they have been laid. 

By instinct, the mother usually picks the best spot in the enclosure to ensure egg survival. 

If you have set up her enclosure properly, the eggs should be fine after this point.

If you need to move the eggs into an incubator, put the eggs in a container with drainage holes and fill it with soil with vermiculite. 

Mist the soil frequently with distilled water to keep it moist. 

Set the incubator to 84° degrees Fahrenheit (29° C). 

Once the hatchlings emerge, keep them in an indoor enclosure. 

For box turtles, the hatchling mortality rate during their first year is very high, and you want to give them the best chance at life possible. 

Make sure to feed them higher quantities of worms, insects, and snails than you would an adult. 

Phase this high-protein diet out as they grow and include more vegetation.

How Do I Sex My Box Turtles?

Before breeding, you will need to know what sexes of box turtle you have. 

This may be a difficult task since both sexes have internal genitalia. 

While most mammals have easily visible genitals, most reptiles keep their genitals inside their bodies, tucked into cloacal vents.

There may be some visible signs, depending on the age of the turtle and the species. 

However, these rules do not apply in all cases. 

Some signs to look for include:

• Male turtles have red irises in their eyes, while females tend to have yellow or brown eyes.
• The shell, face, and foreleg colors may be brighter on males than on females.
• Male turtles’ bottom shells are usually concave, while females’ are flatter.
• Male turtles have a nail on each hind foot which curves inward.

The most reliable visual cue is in the vent and the tail. 

Male turtles have longer and thicker tails, with their vents located further from the back edge of their shell. 

Since male box turtles have long penises, their tails need to be longer and thicker to store them. 

Females will have shorter, skinnier tails, with their vents closer to their shells.

If you want to be sure, you may need to contact your veterinarian or a reptile expert to perform safe sexing procedures. 

If done improperly, methods like venting or popping may injure your turtle.

How Do I Help Wild Box Turtles?

Many native box turtle populations of all species are declining due to habitat loss and the illegal pet trade. 

Helping them regain ground and successfully mate and reproduce involves awareness and sharing information. 

If you have a dog or outdoor cat, make sure to observe them when in your backyard or parks. 

A dog may easily kill a box turtle if it comes across one, and cats are powerful hunters as well. 

Never take a turtle from its wild habitat to keep as a pet. 

Not only is it illegal in many states, but a wild turtle also will most likely not survive its first year in captivity. 

Their strong homing instinct will make them attempt to escape even harder. 

If you want a pet turtle, consult a captive breeder. 

If you find an injured wild turtle, consult your local wildlife rescue.

Be careful while mowing your lawn. 

Female box turtles often look for open, bare spots in the sun to lay their eggs.

Final Thoughts

Box turtles mate between March and April after waking up from hibernation. 

They may not mate every year since they may not encounter turtles of the opposite sex every spring. 

Females then lay their eggs between May and July, sometimes twice in one season.

If you intend to breed your captive turtles, you need to take proper care and make sure they are in the best of health before proceeding.