Can Turtles Change Gender?

The turtle eggs buried in the sand. Incubator turtles outdoor. Conservation of endangered species of large giant turtles in the Andaman Islands India. little baby turtles in the hand of the night

The information is current and up-to-date in accordance with the latest veterinarian research.

The challenging part for new turtles’ parents is determining the gender. I couldn’t identify my turtle’s gender at the beginning. At that early stage, I was wondering, can turtles change gender?

Turtles can change gender because of climate change and embryo development in the hatchling stage. It happens due to the warm and hot sand temperature. Baby male turtle’s gender is changing into the females when they grow up.

But is it possible to prevent turtles from changing their gender? How do you determine if your turtle is male or female? Keep reading to gather more about turtles changing their gender.

Key Highlights

  • Turtles change gender due to ecological imbalance and incubation or hatchling temperature changes.
  • Warmer temperature is the significant reason for the female-biased turtle population.
  • High beach temperatures can change the turtle’s eggs from male to female.
  • However, turtles’ sex determination also depends on the embryonic movement of their eggs.
  • 99% of sea turtles are turning into females because of global warming.

What Causes A Turtle To Be Male Or Female?

The process of determining the gender of turtles is called temperature-dependent sex determination (TSD).

In this process, the turtle’s gender depends on the climate or temperature in the incubation period after fertilization.

Thus, the embryonic movement also influences gender determination in a turtle. It also depends on the hormones during their development stages. When the temperature fluctuates, turtles can even change their gender.

Not only temperature, but some turtle species also have a genotype that determines the turtle’s gender.

In that case, genetic factors are essential in hormonal development. The thing is, genetics and ecological systems both determine the gender of turtles.

According to recent research, warming trends due to climate change may result in more female sea turtles being born. This is because sea turtle hatchling sex is determined by temperature, and warming trends are resulting in more females in many species.

Some sea turtle populations have become skewed towards females due to climate change, and it appears that chemical pollution might also be skewing the sex ratio of sea turtles.

(Source 1) (Source 2) (Source 3)

Ready to get the facts on Life Facts + Turtle Anatomy & Physical Traits? Here’s your turtle-friendly guide. How Does Temperature Affect Turtle Gender?

Turtle Gender Identification Chart

turtle gender identification

For a printable version of this amazing visual chart, click here!

How Do I Know If My Turtle Is A Boy Or Girl?

When I got my first turtle, I couldn’t understand whether it was a male or female. It’s not easy to get the difference at first glance. Then, I discussed this with an expert vet in my town.

He told me I could identify the difference between male and female turtles by checking their features. The features to find the turtle’s gender are tail, shell size, shape, claw length, cloaca positions, markings, and coloration.

For example, male turtles have bigger claws than female turtles. While checking the shell shape,  it’s important to focus on the shape of the plastron. Male turtles have curved plastrons, and female turtles have simple and flat plastrons.

Moreover, the female turtle’s tail is thin and short, and the male turtle’s tail is thick and long. One of the essential differences is the males have a regular-shaped cloaca near the end of their tails, and the female turtles have a round shaped cloaca near the top of their tails.

baby sea turtles

Recent research has highlighted the influence of pollution on the sex ratio of green sea turtles. It was found that exposure to heavy metals like cadmium and antimony, accumulated by the mother and transferred to her eggs, can cause embryos to be feminized. This adds to the already existing bias towards female hatchlings caused by rising global temperatures. (Source)

Male Vs. Female Sea Turtle: What Are The Differences?

As male and female turtles have subtle differences in their body features and behavior, it’s quite tough to differentiate them. But if you look closely, you can see the visible changes in both turtle genders.

Here is the table to help you understand the gender of your turtle by its characteristics and behaviour.

CharacteristicsMale TurtleFemale Turtle
SizeLarger than femalesSmaller than males
Shell shapeCurvedFlat
Reproduction systemThrough mating and inserting spermsMating and laying eggs
TailsThin and longThin and short
Weight10 to 35 pounds10 to 20 pounds
Nesting BehaviourNot active in nestingActively work on the nesting
MatingSearch for mating partners and show their territorial behaviourPicks a perfect nesting location and engages in nesting methods
VocalizationProduce mating callsPrefers to be silent
Travelling rangeOften travel around for different territoryTravels frequently to lay eggs

Trying to get a handle on Shell + Turtle Anatomy & Physical Traits? This page has all you need to know. 10 Surprising Turtle Shell Care Hacks to Keep Your Pet Happy

Does Temperature Determine Gender In Turtles?

As turtles are temperature-dependent reptiles, it plays an important role in determining a turtle’s gender. Not all turtles, but sea turtles can mostly change gender due to climate change.

If the turtle’s eggs are incubated at a high temperature, it can turn out to be female. And when they are incubated at a low temperature, they can be male.

It’s not common in pet turtles because you can control the incubation temperature.

But, the temperature of the sea can change from time to time, and it affects the gender of hatchlings. Mostly, male turtles turn into females when the climate changes in the sea.

a photography of a turtle that is sitting on a rock, mud turtle sitting on a rock with its head inside a ball.

What Temperature Determines The Gender Of Turtle Eggs?

There is no ultimate incubation temperature for deciding the gender of turtle eggs. But after analyzing some well-researched and tested studies, I’ve put them into a table so that you can easily understand the domination of temperature in a turtle’s gender. 

Incubation temperatureGenderReasons
Less than  77° FMaleCool temperature helps to develop the embryos of male turtle hormones.
77°F to 86°FMixed-genderMedium temperature builds up both male and female embryos at the same time.
86°F to 90°FMixed but mostly femaleWarm temperature causes female eggs along with few males.
More than 90°FFemaleHigh and hot temperatures lead to the growth of female hormones. 

Why Does Temperature Affect The Gender Of Turtles?

Turtles’ gender is not genetic or hormonal all the time. Other things like sand temperature or weather are also important. However, dysfunctional environmental warming is the main cause of feminization in turtles.

Around 99% of sea turtles turn into females for the warm temperature. When the sand temperature rises, male eggs can change their gender and adapt to female hormones.

The sex ratio of turtle eggs is there are more female turtles than male ones.

These changes can harm the reproduction of turtles in many ways. Females can’t get mating partners due to the lacking of male turtles. For this reason, sea turtles are losing their populations.

box turtle face eye and nail
Owner: April Kelley McGallion

Got questions about Shell + Turtle Anatomy & Physical Traits? This post has the basics, turtle-style. Are Turtles Born With Shells?

Frequently Asked Questions

Can Female Turtles Have Babies Without A Male?

Female turtles can produce eggs without mating with a male. But they can’t have babies out of these eggs because they are infertile. Male turtles are an essential part of the turtle’s reproduction.

Do Male Turtles Lay Eggs?

Though male turtles have internal reproductive organs, their reproductive role is fertilizing the female turtles’ eggs.  Only female turtles can lay eggs and cover them inside the nesting areas.

What Is The Gender Ratio Of Sea Turtles?

The gender ratio of sea turtles is 80% to 99% female, and the rest of them are male. It depends on the sea temperature and genetic factors. Nowadays, most of the green sea turtles are born as females. That’s why the number of female turtles is rising higher.

How To Prevent Gender Changes In Turtles?

You can prevent gender changes in pet or breeding turtles by controlling the incubation temperature and monitoring their nesting area. But for sea turtles, the only way to stop gender changes is by balancing the ecosystem and preventing deforestation and tree plantation.

Before You Go

Turtles changing gender is one of the main challenges for the survival of sea turtles. If you have a pet turtle born in your home, that means you can balance the sex ratio according to your plan. Moreover, breeders can also control the gender percentage. But this is not possible for the ocean inhabitants.

There are more things you should learn about turtle’s gender. The articles below will give you a complete guide to understanding a turtle’s sex determination.

The Ultimate Guide To Determining A Turtle’s Gender [For Beginners]

How To Tell Turtles Gender Infographic

About Author

Muntaseer Rahman started keeping pet turtles back in 2013. He also owns the largest Turtle & Tortoise Facebook community in Bangladesh. These days he is mostly active on Facebook.