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Male Vs. Female Snapping Turtles (Identification Guide)

As you explore the world of snapping turtles, one of the most common questions that comes up is ‘What are the differences between snapping turtle males and females?’. Today, in ‘Male Vs. Female Snapping Turtles’ we will delve into the fascinating natural history and life history of these snapping turtle species, focusing on aspects like breeding season behaviors and physical differences.

In this article, we’ll cover physical characteristics for identifying gender for both common and alligator snapping turtles, as well as differences in mass, nesting behaviors, and how the temperature of nests can determine hatchling gender.

Along the way, we’ll also cover some frequently asked questions and by the time we’re done, you’ll have a great foundation on the differences between male and female snappers. So if you’re ready, then let’s get started!

If you’ve just brought home a snapping turtle of your own, be sure to check out our snapping turtle care guide before you go!

Male Vs. Female Snapping Turtles: The Common Snapping Turtle

Hatchling Common snapping turtle
It’s a lot easier to check a snapping turtle’s gender when they’re still this size!

In this section, we’ll take a closer look at the identifying features of Common snapping turtle males and females, so that you can identify them and understand a little more about their behaviors.

Cloaca Position

The position of the cloaca is the easiest way to tell a male from a female. This is particularly true of adults and subadults.

The cloaca is an opening underneath the turtle, which is found on the tail. This feature is common in the snapping turtle family, including species like Macrochelys temminckii and Chelydra serpentina. The turtle uses this vent or orifice for laying eggs, mating, excreting waste, and even breathing. The cloaca also contains the male reproductive organ, and you’ll usually see a bulge on the tail.

In females, the cloaca is located right by the plastron (lower shell). In males, the cloaca is located further down the tail. This is because the cloaca contains the male penis and this physical location makes it easier for the male to mount the female during mating.

Putting this into practical application, if you wish to tell the sex of the snapper, simply turn the turtle around and inspect the cloaca. If the cloaca is close right next to the shell, it’s a female.

If the cloaca is further down the tail, then it is a male. Be careful when handling snappers, of course, as they may become frightened and try to bite you!

To check the gender of the turtle, firmly grasp the tail and stretch it out so that it is straight. Flip the snapper so the plastron faces the sky. From there, the position of the cloaca will instantly tell you the gender of the turtle that you are holding!

Plastron Shape

The plastron shape can be used to identify the gender of the snapping turtle. Males have more concave (cup-shaped) plastrons compared to females, who have relatively have flat plastrons.

Size Differences

Body Mass

Common snapping turtle
Males tend to be larger than females, especially once they reach maturity.

Male snapping turtles are considerably bigger than female snapping turtles and you can often use this weight disparity to tell the difference between a male snapper and a female snapper.

Want to know about the biggest snapping turtle in the world? We can tell you about that when you’re done!

On average, male snappers are about 25-50 percent heavier, unless you are dealing with hatchlings or very young juveniles.

Males reach an average body mass of 10 to 35 pounds (4.5 to 16 kg). Females reach an average body mass of 10 to 20 pounds (4,5 to 9 kg), so this information can be useful when determining a common snapping turtle’s gender.

Males also have larger heads, and when you’ve seen examples of both genders a few times, this will be easy to spot. This characteristic is notable in many turtle species, where males often display a large head and long neck, distinguishing them from females.

Shell Length

Males have larger shells. The average carapace (upper shell) length of males ranges from 10.5 to 13 inches (27 to 33 cm), and the average plastron (lower shell) length of males ranges from 8 to 9.5 inches (20 to 24 cm).

By contrast, the average carapace length of adult females is 10 to 11.5 inches (25 to 29 cm) and the average plastron length of females is 7.5 to 8 inches (19  to 21 cm).

This trend occurs in all snapping turtle populations across their geographic range with this particular sizing data being taken from a study done in Virginia.

Nesting Habits

Snapping turtle laying eggs
The Common snapping turtle female will lay eggs even if she doesn’t have a mate.

Mature female snappers nest but males do not. Females do not need to mate before laying eggs, either. If the female hasn’t mated, the eggs produced are simply unfertilized and will not hatch.

As soon as the female has reached reproductive maturity, she can potentially lay eggs, so it is important to have a nesting box if you are hosting a snapping turtle female so that she will have a place to put them (and avoid the risk of retaining those eggs).

Females normally reach reproductive maturity between the ages of 10 to 12 years and will have an average carapace length of approximately 8 to 9 inches (20 to 22 cm) during this time.

There are exceptions — females can technically reach maturity anywhere between 9 to 18 years of age and may have a carapace range of 7.5 to 11.5 inches (19 to 29 cm), but 8 to 9 inches is the most common.

Once mature, a single female can lay about 25 to 45 eggs, and the incubation time is 75 to 95 days. These turtle nests play a critical role in the life cycle of young turtles, often found in regions ranging from southern Canada to the rocky mountains of North America.

The gravid female (a female carrying eggs) nests from late spring to summer and will usually exhibit ‘restless’ behavior.

She will leave or attempt to leave the water often and you’ll definitely notice this — Snappers love the water and try to stay in it 100% of the time if they can. During this time, she will likely find any ground strata in the tank and attempt to dig up a nest.

If she can’t, she may even lay a few eggs in the water, so it is VITAL during this time to provide a nesting box if you have a captive female snapper.

Failure to do so can lead to a problem known as ‘egg binding’, which leads to health complications and may even be potentially fatal.

Sex Determination Based on the Incubation Temperature

An interesting turtle fact is that the temperature of the nest a phenomenon known as temperature-dependent sex determination, affects the sex ratio in hatchling snapping turtles. If you are the breeder you can use this information to determine or even to ensure the likely sex of the hatchlings.

Very high or very low temperatures will ensure a clutch of mostly females. For instance, An incubation of 68 degrees Fahrenheit produces only females, and temperatures above 82.4 degrees Fahrenheit will also produce only females.

An incubation temperature of 73 to 75 degrees Fahrenheit will produce only males and an incubation temperature of 70 to 72 degrees Fahrenheit will produce a mix of both females and males.

If you’re checking the gender of a juvenile snapping turtle, then you’d better know how to properly pick one up to avoid a nasty bite! Find out how it’s done when you’ve got a moment!

Male Vs. Female Snapping Turtles: The Alligator Snapping Turtle

An Alligator snapping turtle takes an aggressive stance
Alligator snapping turtles have armor that you simply cannot miss!

Now that we’ve covered the common snapping turtle, let’s take a look at alligator snappers. You’ll see that a lot of the differences will be similar to what you find with common snappers, with the exception of the alligator snappers’ superior size.

Let’s take a look and you can see what we mean!

Cloaca Position

As with common snappers, the easiest way to tell the difference between an adult male and an adult female alligator snapping turtle is to simply inspect the position of the cloaca. 

The cloaca of the female is located close to the shell (plastron – the lower shell that covers the underside of the turtle), while with males, the cloaca is far from the shell and is further down the tail.

You will also notice a telltale bulge on the tail of the male to further confirm the gender identification, although it will be much less pronounced if you are trying to sex a hatchling.

Size Differences

Body Mass

Alligator snapping turtle in enclosure
Be careful when you check a snapper’s gender – especially alligator snappers!

Males are generally larger than females, although the differences are most apparent when the specimens are mature. This size difference is considerable so you can use it to help you identify the gender of an alligator snapper in many cases.

Males can reach a mature body mass of over 220 pounds, although 155 to 175 pounds (70-0 kg) is more typical. Inhabiting a wide variety of aquatic habitats, including slow-moving water and wetland areas, these turtles display notable sexual dimorphism.

The largest male alligator snapper recorded was caught in 1937 in Kansas and weighed over 403 pounds (approx. 183 kilos), but this is VERY rare.

Females on the other hand are much smaller, they typically weigh 50 – 62 pounds 22-28 kilograms) but generally reach a mass of under 60 pounds (about 27 kilos).

Shell Length

Male alligator snappers usually sport carapace lengths of up to 29 inches (73.7 centimeters). Females are considerably smaller, with carapace lengths of up to 22 inches (55.9 centimeters).

Tail Size

Males have longer tails than females, as the tail also houses their reproductive organs. Those organs are located further down the tail so that they are ideally positioned for mounting the female during mating.

Nesting

Female turtles lay eggs and males don’t, so if you see an egg in the tank, then your turtle is definitely female. The eggs look like ping pong balls and have a somewhat flexible shell, so they are definitely hard to miss!

While males reach maturity at 9 years, females reach maturity at 11 to 13 years — with the exception of a few females who may not reach maturity until as late as 18 years. Once the turtle reaches maturity, it will start to lay eggs, even with no males present.

Female alligator snappers nest in late spring to summer and when the urge hits, the female will become restless. Like common snappers, alligator snapper females will suddenly ‘need’ to get out of the water.

They will act restless and may start digging in the substrate of the tank, and you might even see a few eggs in the water. This is to avoid egg impaction also known as dystocia, ‘egg binding’, or ‘ovostasis’.

If the female doesn’t have a place to nest, sometimes she will retain eggs inside her, and when they harden it can cause serious health complications or even prove fatal.

As such, if you suspect that your snapper wants to nest, then be sure to provide it a nesting box in which to do so.

The National Wildlife Federation has some more info on alligator snapping turtle eggs and more that you can read here if you would like to learn more!

Sex Determination Based on the Incubation Temperature

Digital infrared thermometer
The gender of snapping turtles will be determined largely by the temperature in the nest.

The sex of alligator snapping turtles, just like with common snappers, is determined by the temperature of the nest. So, if you are incubating the eggs and have the right thermometer, then you can tell the sex of a hatchling before it leaves the egg!

Breeders use this information all of the time!

By keeping the temperature of the nest/incubator at 77 to 80.6 degrees Fahrenheit (25 to 27 degrees Celsius) they will get male hatchlings and the temperature at 84.2 to 86 degrees Fahrenheit (29 to 30 degrees Celsius) will produce female hatchlings.

Temperatures of 72.5 to 75.2 degrees Fahrenheit (22.5 to 24 degrees Celsius) will also produce female hatchlings, although a small number of them may be male.

On the other hand, hotter temperatures of 82.4 to 86 degrees Fahrenheit (28 to 30 degrees Celsius) tend to produce only female hatchlings.

In this case, you are actually deciding the gender of the hatchlings, rather than identifying it, but it essentially works out the same.

Frequently Asked Questions

How do you tell a female from a male snapping turtle?

There are several ways to tell the sex of a snapping turtle but the easiest is by inspecting the vent on the tail.

With males, the vent (cloaca) is far down the tail, and on females, it will be located very close to the shell.

Are male or female snapping turtles more aggressive?

Male snapping turtles are more aggressive than female snapping turtles, but female snapping turtles are still quite aggressive. You should be cautious when approaching any snapping turtle regardless of their gender. As the name suggests, they ‘snap’!

Do male and female snapping turtles look the same?

Males and female snapping turtles look the same without close examination. Males are generally bigger, but this is only helpful with older turtles, as they are very close in size when hatchlings or juveniles.

Conclusion

It may be necessary to know the sex of your snapping turtle. After all, you might wish to breed them or just identify if your turtle is female, you can prepare a suitable nesting area for it.

You might even just be picking a name, but whatever the case, now you know how to tell!

Just keep in mind a handful of traits and identifying your turtle’s gender should be a piece of cake. Starting off, males are considerably larger than females as they get close to closer to maturing. They also tend to have larger heads and larger tails.

Next up, check the location of the cloaca. The female’s cloaca is located close to the plastron (lower shell), while the male’s cloaca is located further down the tail and typically exhibits a noticeable bulge.

Females lay eggs, males don’t, so if you see an egg then you’ve got a quick answer! Finally, speaking of those eggs, the incubation temperatures needed to hatch males are different from the incubation temperatures needed to hatch females.

Remember, whether you’re observing wild snapping turtles in their natural habitat among aquatic plants and brackish water or studying them in a field guide, understanding their unique characteristics like the small plastron, powerful jaws, and structure of the tail enhances our appreciation of these fascinating creatures.

Now that you’ve got the basics, you should be all set. Thanks so much for reading and we hope to see you again soon!

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