Supposedly only males have orange eyes. This photo shows a female three-toed.

Turtles: How to Tell Male Box Turtles from Females

Sexing turtles (determining if one is a male or a female) can be tricky here at the Ornate Bird Garden!  Here are some distinguishing traits I've noticed. Some are more reliable than others!

• Color on face/forelegs
• Claw on hind foot
• Eye color
• Shape of plastron
• Overall size
• Tail
• Sex organ  (it doesn’t get much more reliable than that!)

Color on the face and forelegs.  Supposedly the males have more bright orange and red markings on their faces and forelegs.  Supposedly it's the males rather than the females that will have a bright green head. Well, not necessarily. My female three-toed box turtle Potscrubber has beautiful orange markings all over her face, and little Daisy the female ornate has a bright green head.  My one male Osiris the ornate has uniformly drab markings.

Female Horus has the more typical pale-yellow eyes.

Claw on hind foot. Supposedly males have a long claw on their hind feet that curves inwards.  This is to help a male hold onto a female when mounted on her.  Well, maybe. My male ornate Osiris actually does have such a claw.  I try never to pick him up since I know he doesn't like it, but whenever I do, he curves his hind leg around my wrist and hangs on for dear life with that claw.  So there may be something to this trait.  Certainly he has the claw and the instinct to hold on with it. But there are better traits to check than the claw:  read on.

Eye color. Supposedly males have red or orange eyes, and the females have yellow or pale brown eyes. This seems to be true. My male Osiris has bright orange eyes. My two female ornates Daisy and Horus have pale yellow eyes. However, my female three-toe Potscrubber has bright orange eyes!  I'd say that you can use eye-color as a backup characteristic to check, but that it's not 100% reliable.

Male Osiris’s tail is long & thick with the vent placed about halfway down.

Shape of the plastron. The plastron is the bottom part of the shell.  Supposedly a male's plastron is concave, meaning it has an inward depression.  This is so he can mount the female, and the top of her carapace (upper part of shell) will fit into his plastron and he can keep his balance. The female's plastron is flat since she won't need to mount anyone (though she might if she's aggressive, and trying to dominate another turtle).  However, in ornates the plastron seems to be flat in both males and females. Plus, for me, studying the plastron is about like studying the claw on the hind-foot. It's just too small a detail!  It's hard to read any meaning into what you see in one turtle unless you have several other turtles to compare.

Overall size. Supposedly males are bigger than females.  Well, I guess.  The four males I had in 2005 were among the biggest of my turtles. But I also had an ornate female (whom I eventually relocated to another home since she was so aggressive) who was bigger than Osiris, my male ornate.  She was the same size as the next smallest male ornate. So I didn't consider overall size to be an especially helpful variable to check. Besides, it's like the claw and the plastron again.  How does it mean anything in the individual turtle unless you have a lot of other turtles to which to compare it?

As you can see, female Potscrubber doesn’t have much of a tail!

The tail. This is THE characteristic that I look for.  A male is going to have a long, thick tail.  The vent in his tail (that is, the opening through which he makes his droppings) will be set further down his tail (away from his shell) than the vent in a female's tail. Her tail will be tiny and skinny.  All of my females have tiny little tails. When I first picked up Potscrubber when rescuing her on the street (see My Turtles), I wasn't sure what species of turtle she was, but I knew she was a female by her tail. You won't even need other turtles to compare:  the differences in a male's tail and a female's tail are that obvious.  This leads me to the most reliable sexing characteristic of all.

Sex organ. It doesn't get much more obvious than this:  if you see a penis, you have a male.  You will rarely see your turtle's penis, however, because he keeps it inside his tail. (Hence the need for a long, thick tail.) You might see it if you catch him in the act of mating.  The other situation is when he's “fanning" his penis. This isn't as exhibitionist as it sounds.  Basically, a male climbs into his water dish, extrudes his penis from the vent in his tail, and swishes it around in the water.  No one knows why he does this!  Maybe it's to cool it off on a hot day. 

The first time I saw Osiris do this, I almost panicked because a turtle penis looks like a strange, purple, multi-lobed flower. I assumed that he had somehow lost one of his internal organs like his liver, which is what it looked like (yes, go ahead and laugh!), and I'd have to take him to the vet! Thankfully, he managed to get his penis back inside his body after a few moments, and then strolled away from the water dish.  No big deal! 

There is an awful situation known as a prolapsed penis that can happen to a reptile when he extrudes his penis for whatever reason, and then can't withdraw it back through his vent because it has dried out!  It requires the immediate attention of an experienced reptile vet.  I've heard that this is most common in iguanas. 

Back in 2005, I thought that this might be about to happen with one of my male turtles.  I caught him mating with my female ornate Horus, and poured a dish of water over them to break it up.  (I didn't want turtle offspring!) Horus obligingly scurried away into a hiding place, but the poor male had his penis extruded and he didn't seem willing or able to get it back inside his body anytime soon.  I put him in a mixing bowl with water up to his plastron; he couldn’t climb out, and after about 15 minutes, he was back to normal and I released him in the back yard.

Note: I can’t recommend this book highly enough. It’s available on Amazon through this link:

The Box Turtle Manual (Advanced Vivarium Systems)