Sexing Box Turtles – Quick Way to Tell Male for Female

Box turtles are quite common and popular pets, despite their difficulty in long-term care and maintenance.

These turtles aren’t ideal for complete beginners, but this doesn’t mean you can’t try your shot at one. It’s not impossible with the right information, preparation, and a ton of commitment.

However, before getting your turtle to begin with, you need to learn the difference between a male and a female.

This can come in handy later on if you plan to breed your pets or simply sell the turtle, in which case you need to know what you have.

Male vs. Female Box Turtle – What is the Difference?

I promised a quick way to tell male from female box turtles and I kind of lied a bit. There’s no single way to distinguish between the 2, but rather several.

Fortunately, they’re several quick ways, so let’s dive right in:

Size and Shape

There are quite a few differences between box turtle males and females in terms of overall appearance. For instance, box turtle males are larger than females and capable of reaching up to 7 inches. Females will barely reach 5 inches if that.

Then you have the overall shape. Males have flatter and wider shells, while females possess taller ones. This feature is quite easy to notice, and I would say it’s the best indicator of a box turtle’s gender, even lacking any other additional info.

You only need to make sure that both of the turtles you’re comparing are adults because turtles change in shape and size as they grow.

You also need to make sure you’re not comparing a juvenile male with an adult female or vice-versa. The difference in age comes with significant differences in appearance, as well.

Shell Pattern

Aside from the shell size and shape, the color pattern is also different between the 2 genders. Males, for instance, tend to have clearer shell separations and more vibrant colors, which include more yellow than females.

Females have more faded shell separations with more black thrown into the mix as well.

However, this is a more uncertain indicator because it’s not constant. Sometimes, it simply doesn’t apply because some males can come with black shells, making them resemble females. So, always corroborate the shell pattern with other indicators just to be sure.

Eye and Head Color

The eye color is different between males and females. Males exhibit red or orange eyes, while females stick to brown. The same clear distinction is visible in terms of head coloring.

Males tend to have a lot of yellow on their necks, faces, and heads, while females showcase blander and duller colors, typically black, with very little yellow.

Many females also exhibit grey head coloring, making the gender-based difference even clearer.

Male Eastern Box Turtle
Male Eastern Box Turtle

Tail Length

Male box turtles possess longer and thicker tails than females. This isn’t a random feature or difference but one born out of necessity.

Males use their tails for support during mating when they need to use the caudal limb to balance themselves when mounting the female. The concept is similar to what kangaroos are doing when posturing up, ready to fight.

Females don’t need that, so they have shorter and weaker tails, with only limited use. However, as with all of the other indicators we’ve mentioned, this one can also lead to confusion.

That’s because juvenile males can have a similar tail size and shape to adult females. So, you should always have the turtles’ age as a baseline before starting any comparison.


The plastron is nothing more than the shell-like structure that covers the turtle’s underbelly. This section is flat for females and concave (bent inward) for males. Again, as with the tail, the plastron’s anatomy relates to the male’s mating capabilities.

During mating, the male mounts the female from behind. This means that the indentation visible in the male plastron has a pragmatic role, allowing the male to remain stable when on top of the female.

The male box turtle uses its plastron indentation, tail, and limbs to stabilize itself when mounting the female.

A rather delicate task, given the female’s round and slippery shell. This, combined with the fierce male competition, turns the mating process into quite a chore.

Hind Claws

Males possess longer and sharper hind claws, while females exhibit shorter claws. Males’ claws are larger because you guessed it, they help with mating.

In short, males use their tails and frontal claws to climb and stabilize themselves on the female and rely on the hind claws for an additional grip.

The hind claws may also serve as self-defense tools, providing the male with extra grip when fighting other males.

Vent Location

The location of the vent (essentially the cloaca) varies a bit between males and females. In males, the vent is located in the middle of the tail, closer to the tail tip.

In females, though, the cloaca is slightly larger and located more toward the base of the tail.

The difference may not be immediately visible, but you should be able to identify it upon comparing the 2 genders side by side.

Female Eastern Box Turtle
Female Eastern Box Turtle

Activity Level

Males tend to be slightly more active and energetic than females, which has multiple potential explanations. One of them comes from the need to establish, patrol, and protect their territorial boundaries from other males.

Another explanation is that males are constantly on the lookout for potential mates, so they tend to be more restless and energized than females.

Females prefer to save their energy, eat up, and deposit fat and nutrients for when the mating season comes. At that point, the reptile will tap into these resources to aid in egg formation and development.

Feeding Habit

Box turtles are generally omnivorous, so they consume a variety of fruits, veggies, insects, and even fish and frogs. But the animal’s diet also depends on its gender. Males tend to require a lot more animal protein, especially when near the mating season.

This corroborated with the male’s more active lifestyle overall, causing them to burn and require more calories overall. Females are typically chill, almost always in an energy conservation state.

However, it should be noted that female box turtles can also increase their feeding frequency and require more protein when gravid.

This is because their bodies require an additional influx of nutrients to aid with egg formation.

Also, bear in mind that the turtles’ dietary preferences and meal frequency and size vary drastically over time, depending on the turtle’s age, size, environmental parameters, and several other factors.


This one should be fairly obvious. Male box turtles tend to be more aggressive overall, especially toward other males.

This is due to their enhanced territorial tendencies, as well as their born competitional drives, forcing them to fight over females, space, resources, and pure hierarchical dominance.

However, note that females can also become more aggressive in some instances. These include mating when fighting off males or when threatened or stressed by other females.

Mating Behavior

This should be one of the clearest gender indicators you can get. All you need is to assess the turtles’ behavior prior to and during mating to tell the difference between the 2.

In short, males are those that chase the females around the enclosure, attempting to mount them. If you see one turtle mounting the other from the back, this should immediately inform you of their respective genders.

Also, keep in mind that males are more likely to engage in fights with one another during mating.

This is a normal drive since they’re all attempting to procreate and ensure the continuation of their genetic material. But females can also attack males if the latter becomes too persistent.

So, if you have several box turtles and you notice 2 of them fighting, and it’s a mid-mating season, you’re looking at a pair of males.

If one of them attempts to fight off the other, the aggressive one is the female, and she’s bothered by the male’s persistence.

Egg Laying

You can’t really tell whether the turtle is gravid or not. At least, not until the time to lay the eggs has come.

This should make things considerably simpler because the turtle laying the eggs is clearly the female.


As you can see, there are several ways to sex your box turtles properly, and you should always corroborate several of them just to be sure.

Aside from a couple, most of these differences can apply to both genders, depending on the case.

Robert from ReptileJam

Hey, I'm Robert, and I have a true passion for reptiles that began when I was just 10 years old. My parents bought me my first pet snake as a birthday present, which sparked my interest in learning more about them. read more...