Indian & Burmese Star Tortoises
- male vs female -
Subadult Burmese Star tortoise female. Notice the short, stubby tail and the roundish shape of the bony tail opening to allow for egg laying.
Boy or girl?
Determining the gender of young Star tortoises is not always straightforward because most of the gender characteristics apply to subadult and adult tortoises only. Burmese Star tortoises can be especially tricky to sex when young. Some young males can look more like girls for quite a while. See the example photos below.
Very young male Star tortoises have flat plastrons and short tails, but the tail will grow and the plastron will concave as the male grows and matures. Many male youngsters start out looking more like females and then suddenly grow a big tail.
Some subadult individuals are easily sexed because one or more of the sex characteristics is quite obvious. With others, figuring out the gender is more difficult due to ambivalent sex traits. In those cases, you'll need to consider all the attributes as a whole.
Gender traits in ADULT Star tortoises
1.) Overall size:
- Adult females are much larger than adult males.
2.) Shell shape:
- Females are typically more rounded in overall shape, while males are more elongated. Male tortoises can also have more flattened shells.
- Females have flat plastrons and adult males have concave plastrons. Male's concave plastron aids in mating. As youngsters, both sexes have flat plastrons.
- Females have short, stubby tails. Males have bigger and longer tails. In addition to overall size, this is the most noticeable gender characteristic in adult tortoises. As youngsters, both sexes can have short tails.
- Mature Burmese Star tortoise males may have a terminal tail spur. Scroll down to photo.
5.) Angle of anal scutes:
- In males, it's very open with a wider angle. In females, the angle is narrower, and the opening may be more roundish to allow passage of eggs. In adult females, the tips of the anal scutes tend to point towards the back and in adult males more towards the sides. However, the shape of the anal scutes varies from individual to individual and can change in the same tortoise as it matures.
6.) Growth rate:
- Among siblings raised together, females can grow faster than males. However, faster growth alone is not a reliable gender indicator. Any tortoise can grow fast depending on circumstances.
- Many Indian Star tortoise boys start to "flash," i.e., show their private parts, in a warm bath when they reach the weight of 200-300 g. This is often the first sure sign that you have a male. :O)
Note: For reference, see the shell scute diagrams.
Characteristics of adult female Star tortoises
Adult Star tortoise females have short, fat, stubby tails with a little tip. Angle of the anal scutes is narrower than in males, and the bony opening is often roundish to allow the passage of eggs. The supracaudal scute does not curve down as much as in males, but opens up for egg laying. The cloacal opening in the tail is roundish, looking kinda like a star.
Female Star tortoise
Characteristics of adult male Star tortoises
Adult Star tortoise males have long, thick, deep letter V shaped tails. Anal scutes can be shaped like a mustache with the tips pointing towards the sides. The supracaudal scute typically turns strongly inwards in adult males. Assumably, to protect the tail and male organ. The cloacal opening looks more like a slit towards the tail.
Note: The direction of the supracaudal scute varies among individual tortoises and different species. For example, in my Golden Greeks, both males and females have supracaudal scutes that open up. On the other hand, in my Angulate tortoises, both males and females have supracaudal scutes that turn under.
Male Star tortoise
Simple rules for sexing tortoises :O)
- If the tortoise looks like a boy, it's a boy.
- If the tortoise looks like a girl, it could be a girl or a boy.
Subadult & adult tortoises:
- If the tortoise flashes, you know for sure you have a male.
- If the tortoise lays eggs, you know for sure you have a female.
Examples - young Burmese Star tortoises
This Burmese Star baby was easy to sex. As a hatchling, he already had a long, male shaped tail. Indeed, he turned out to be a boy.
Here's another little Burmese Star hatchling. Eventhough the bony opening and tail look a bit boyish at this point, it's a girl. One clue for girlness can be a rounded, less oval, shell shape like here.
Ok, how about this Burmese Star tortoise youngster. Is this a boy or a girl? Tail is short and stubby looking and the bony opening is circular. Must be a girl, right? Nope. This tortoise is too young to sex accurately because it hasn't developed the male gender characteristics yet. He turned out to be a boy!
For comparison, here's a young Burmese Star female. She doesn't look that different from the male above. Tail is short and stubby and the bony opening is roundish.
Here's a young male. Tail is big and long, but the bony opening is still roundish. It will change over time.
Examples - adult male Burmese Stars
Mature Burmese Star tortoises may have terminal nail spurs. They are not present in younger males.
Mature Burmese Star tortoise male with a tail spur (terminal nail).
For comparison, here's a another male Burmese Star tortoise. His tail has spur had not yet developed when the photo was taken. He was probably about 7 years old when his tail spur started to grow.
Examples - Indian Star females
Adult female Indian Star, Sri Lankan type. Notice the short, stubby tail.
The tail is short in females.
Female tail from the underside. Photo courtesy of Philip Chan.
Female Indian Star tortoise with a clear stubby tail and a round bony opening. Photo courtesy of Zoltán Horváth.
Examples - Indian Star males
The tail is big and long in males.
Another big male tail. Photo courtesy of Philip Chan.
Male. Notice the size and long length of the tail.
Male. Notice the inward curve of the supracaudal scute. Photo courtesy of Zoltán Horváth.
Adult male Star tortoise's concave plastron. Photo courtesy of Jitka.
Example - Indian Star pair
Female Geochelone elegans may grow 2-3 times the size of a male! Photo courtesy of Zoltán Horváth.
Indian Star pair. Notice the size difference. Photo courtesy of Zoltán Horváth.
Flashing vs prolapse
Young male Star tortoises often "flash," i.e., show their private parts, in a warm bath. This is often the first sure sign that you have a male. The tortoise male part is sometimes described as looking like a purple flower, a cowboy hat, or the Starship Enterprise. :O)
Many new tortoise owners become alarmed when they see their male tortoise "flash" for the first time. They often think there's something terribly wrong with the tortoise, for example, an intestinal prolapse.
As long as the private part goes back in after a short while, everything is ok. If it prolapses and stays out, take your tortoise to the vet ASAP to have it treated. Otherwise, it may become necrotic and have to be amputated.
On a rare occasion, you may catch a glimpse of your female's private parts as well. The female part looks similar to a male's, but it's much smaller and doesn't have a long stem. More likely though, it's probably just a young, maturing male tortoise showing his immature bits. In boy tortoises, the bits start out small and then grow bigger as the tortoise matures.
Link - Here's a link [Scientific American, offsite] to a science blog with photos of "flashing" male tortoises, including a male Geochelone elegans. WARNING: Photos on that page are very graphic. They many not be suitable viewing for young children.
Link - For comparison, here's an article about intestinal prolapse with photos [Tortoise Trust, offsite]. Intestinal prolapse, or prolapse of any other internal parts, is an emergency.