Radiated gender determination

Anyfoot

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Hi all

In my quest to learn more about this species and although I'm way off knowing the sex of mine, Can anyone tell what the differences are between male and female radiated please.
Would really appreciate photos if possible.

Thanks.

Craig
 

Sterant

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I can say that the absolute biggest difference is that males have a penis and females do not. (had to do that)

In addition to that, once sexually mature, generally speaking:

Males will have a much larger tail than females.
The plastron of a male will be rather concave.
The plastron of a female will be rather flat.
All things being equal, males are larger. That doesn't mean that your male will be larger than your female - just that males have a maximum size that is larger than females.

There can also be differences in the anal scutes, but the items above are easier to make out.

Behaviorally (and other than mating behavior), males tend to be more outgoing while females are more shy / reserved, but that varies.

@zovick might have something to add / correct / expand on.

Dan
 

TammyJ

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It's easy to tell that this is a guy discussion.
Just check the first sentence in that response by Dan.
Males are described by what they have.
Females are described by what they do not have.
Just joking!!!;)
 

Sterant

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It's easy to tell that this is a guy discussion.
Just check the first sentence in that response by Dan.
Males are described by what they have.
Females are described by what they do not have.
Just joking!!!;)
Females dig nests - males couldn't possibly handle that.

Females lay eggs - Guys laying eggs?!? You kidding me, they could never handle the pain.
 

zovick

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Unless you have those tortoises endoscoped, you will not be able to tell what sexes they are until they are 8" to 11" in length. You might happen to see a tell-tale penis evert at some point along the way, but even that doesn't usually happen until they are at least 8" to 9" in length.

Here are two roughly 6" to 7" long specimens. The male is on the left and the female is on the right. Going by visual clues such as their anal scute shapes, one would be inclined to guess just the opposite. Their tails are virtually identical in size and shape at this time also.

Plastron Shot #1494 (L) and #1475 (R).jpg
 
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Anyfoot

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Unless you have those tortoises endoscoped, you will not be able to tell what sexes they are until they are 8" to 11" in length. You might happen to see a tell-tale penis evert at some point along the way, but even that doesn't usually happen until they are at least 8" to 9" in length.
@zovick I know mine are years away from sexing. I wanted to find out what the differences are in the adults.
For example, anal scute shape, male to female size, does any gender take a slightly different carapace morph when older like in redfoots?
 

Markw84

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I am not aware of any books written solely about the Radiated Tortoise.
Bill,

Love the pictures and your insight. Find this fascinating as I haven't dealt with radiata personally. Do you have similar pictures you could post showing full adults? What anal scute shape becomes characteristic, or other features your look for. For example, I know with a sulcata I watch gular development, anal scute shape, concavity, and tail size. With a G. platynota, I look for anal scute shape, concavity, tail size, and overall carapace shape.
 

zovick

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Bill,

Love the pictures and your insight. Find this fascinating as I haven't dealt with radiata personally. Do you have similar pictures you could post showing full adults? What anal scute shape becomes characteristic, or other features your look for. For example, I know with a sulcata I watch gular development, anal scute shape, concavity, and tail size. With a G. platynota, I look for anal scute shape, concavity, tail size, and overall carapace shape.

Well, I don't have any plastron comparison photos of adult Radiateds, but here are an adult male (L) and female (R) pair of G. platynota. The following characteristics are virtually identical in these platynota and Radiated Tortoises:

in males, the tips of the anal scutes point to the sides (laterally) rather than pointing straight back, The anal scutes become somewhat bulbous or raised overall, rising above the plane of the femoral scutes a good bit, and the plastron itself also becomes quite concave. The tail becomes longer and thicker. The supracaudal scute frequently curls inward.

In females, the tips of the anal scutes point straight back. The anal scutes themselves are flat and on the same plane as the femoral scutes and the rest of the plastron which is also virtually flat. The tail is relatively short. The supracaudal scute does not curl inward in adult females (except in a few rare cases) because its doing so limits the ability of the female to lay her eggs. There normally is a fairly good sized round opening between the two anal scutes and the supracaudal scute to allow eggs to pass through easily.

Platynota Comp 2.JPG Platynota Comp 1.JPG
 
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Radnoisseur

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Hi,

Post #6 and Post #11, the photos does contradict one another if I may point out because #6, the male is a narrow V shape (towards the center), and female is a wider V shape (scutes pointing to the sides), but then on post #11 with the Burmese as an example, the description is inverted so it got very confusing.
 

zovick

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Hi,

Post #6 and Post #11, the photos does contradict one another if I may point out because #6, the male is a narrow V shape (towards the center), and female is a wider V shape (scutes pointing to the sides), but then on post #11 with the Burmese as an example, the description is inverted so it got very confusing.
Yes, you are correct. I posted the photo in post #6 simply to illustrate how confusing it can be to try to visually sex young Radiated Tortoises. If you look at the photos in post #11, those pictures show EXACTLY what adults of both sexes look like. The plastra of adult Radiated Tortoises look just like the adult Burmese Stars in my photos (male is on left, female is on right).

The narrative description in post #11 is spot on as well, so use that post to determine sexes.
 

Radnoisseur

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Yes, you are correct. I posted the photo in post #6 simply to illustrate how confusing it can be to try to visually sex young Radiated Tortoises. If you look at the photos in post #11, those pictures show EXACTLY what adults of both sexes look like. The plastra of adult Radiated Tortoises look just like the adult Burmese Stars in my photos (male is on left, female is on right).

The narrative description in post #11 is spot on as well, so use that post to determine sexes.

Gotcha. The reason I am trying to use #6 as a reference point is because I got my eyes on some 6-7" ones and trying my best to see if I get much luck picking out a female but #11 throws me off.

The ones I am looking at now looks like #6 on the (left side) where the tips of the anal scoots point straight back. If they hold this shape than - theoretically - as they get larger, it would look more like a crescent of #11 which would be females, correct?

Btw I searched high and low for your contact Bill, hoping you can point me in the right direction where your lines are in CA so I can connect with those breeders and hopefully get some? Your line is absolutely gorgeous and have been reading so many articles and care sheets written by you on the Rads :)

Please direct message me if you can sir. Thank you
 

zovick

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Gotcha. The reason I am trying to use #6 as a reference point is because I got my eyes on some 6-7" ones and trying my best to see if I get much luck picking out a female but #11 throws me off.

The ones I am looking at now looks like #6 on the (left side) where the tips of the anal scoots point straight back. If they hold this shape than - theoretically - as they get larger, it would look more like a crescent of #11 which would be females, correct?

Btw I searched high and low for your contact Bill, hoping you can point me in the right direction where your lines are in CA so I can connect with those breeders and hopefully get some? Your line is absolutely gorgeous and have been reading so many articles and care sheets written by you on the Rads :)

Please direct message me if you can sir. Thank you
Thanks for the kind words.

Yes, you are correct. When the tips of the anal scutes point straight back, that would indicate a female. The older the tortoise is, the more reliable that factor is. That is why I posted the photo in post #6 to show that in younger Radiated Tortoises, this fact may not be too reliable. The older the Radiated Tortoise is, the more reliable that anal scute factor will be.

The Behler Center probably has the most closely related bloodlines to mine in CA right now.
 

Radnoisseur

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Glad to hear. I will post as many photos as a I can once I pick them up :)

Yeah I've talked to a few Rad keepers that would not get anywhere from that center even a year in of initial contact so they all gave up. Their short answer is "good luck!" Haha

And I quote: "The center isn't focused on selling. You can't pick out what you want, they won't send a single photo as they only sell culls that aren't selected for their breeding program. In the off chance you could get somewhere they charge market prices so what's the point."

I've tried myself since April and have yet gotten anywhere so guess my case wouldn't be any different 😅
 

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