The Geochelone sulcata, or African spurred tortoise, is also commonly called by other names: the spurred tortoise, the African spurred thigh tortoise, the sulcata tortoise, and the grooved tortoise. This tortoise's habitat extends across North Africa's Sahara Desert from Mauritania to Eritrea. It is native to Africa and is the third-largest species of tortoise in the world.
Itās easy to distinguish between males and females of some animals, regardless of whether they are adults or juveniles. However, when it comes to sexing Sulcata tortoises, it takes more than just a quick glance at their physical appearance. Whether you have just purchased one as a pet, or your current female has laid some eggs, it is important to understand how to sex a sulcata tortoise.
While many people use the terms "tortoise" and "turtle" interchangeably, they are technically different. Tortoises live mostly on land, while turtles are more adapted to live in water at least part of the time. Turtles and tortoises are the only species that have backbones and also have shells. Their shells, which are made of between 59 and 61 bones, are covered by scutes, which are plates made of keratin, like very strong fingernails. Their legs are very different too. Turtles have legs that are more like flippers to help them swim.
Here we will delve into the key differences between male and female Sulcata tortoises, covering everything from physical characteristics to behavioral indicators.
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Why Sexing Your Sulcata Tortoise is Important
Sulcata tortoises are currently listed as vulnerable by the IUCN. Therefore, breeding programs are imperative in order to grow population numbers. An important part of these much needed breeding programs involves knowing the sex of tortoises to facilitate controlled reproduction. It means that breeders can pair compatible individuals to produce offspring with desirable traits or contribute to conservation efforts. It also helps to ensure genetic diversity and healthy populations within captive breeding programs. Additionally, being able to sex tortoises allows breeders to monitor and manage the breeding process effectively, leading to successful reproduction and the continuation of the species.
Interestingly, a single male is enough to mate with at least 4 females.
Understanding the health care needs of male and female tortoises is essential for ensuring their well-being. Like all animals, care requirements differ based on sex. For example, female tortoises need specific care during egg-laying periods, such as providing a suitable nesting area and monitoring their calcium levels to prevent issues such as egg binding. On the other hand, male tortoises will exhibit particular behaviors during the mating season that often require specific attention. By tailoring your Sulcataās care based on their sex-specific needs, youāll be better equipped to maintain the health and happiness of your Sulcata tortoise in the long term.
Sulcata tortoises are generally solitary and typically only come together in the wild for breeding purposes. Females tend to be less aggressive than males and are more likely to be seen together in the wild, such as coming together to forage in areas with a high density of food. However, they are unlikely to exhibit any social behaviors with one another. Male tortoises in particular can be territorial and aggressive, so should not be kept together.
Differentiating Between Male and Female Sulcatas
Like other reptiles, determining the sex of a Sulcata depends somewhat on egg incubation temperature and weather. Eggs incubated under warmer temperatures are more likely to be female, whilst those incubated under cooler temperatures are more likely to be male.
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Sulcata tortoises can generally be sexed reliably when their shell length reaches 10 to 12 inches, this is typically at the age of around 5 years old. Bear in mind however, that growth rates can vary based on diet, environment, and overall health, so some tortoises might be sexed accurately a bit earlier or later than others.
At around this stage in maturity, certain features, known as secondary sexual characteristics, become easier to distinguish.
Key Physical Differences
As the spurred tortoise grows, it can be seen that the underside shell, called the plastron, is flat in the female but concave in the male. The anal scutes, which are located on the plastron near the tail, form a V shape but are flared in the male and narrower in the female. Attached to the plastron but visible from the front of the tortoise under the head are the gulars, which are larger in the male.
- Males have longer, wider tails with a spur on the end. Females, however, have less conspicuous tails. They are shorter and blunt and the cloacal opening is near the base.
- The gular scutes (the part of the shell that projects under the neck) are more pronounced and longer in males than in females.
- Males usually have a concave plastron (the underside of the shell), which helps them mount females during mating. Females have a flatter plastron.
- Males have broad anal scutes (located on the plastron at the rear end of the tortoise) that form a wide āVā shape. Conversely, female anal scutes are more circular in outline and form a āUā shape. This creates a larger opening that aids the laying of eggs.
In terms of sexing newly hatched Sulcatas, you will need to take it to a veterinarian who will perform an endoscopy.
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Size Matters
Size is one reliable way to tell if you have a sulcata tortoise girl or boy. Like many species in the animal kingdom, male spurred tortoises are significantly larger than females. Male adults can grow to be 30 inches long and weigh as much as 220 pounds, while adult females can be as large as 18 inches long, weighing over 130 pounds. In fact, spurred tortoises are the largest land tortoises in the world.
As is typical with many other tortoise species, males tend to be larger than females. Male Sulcatas weigh at least 120 pounds on average, whereas females are typically between 65 and 75 pounds. Additionally, males average a length of 24 inches, and females are around 16 inches in length. Moreover, males tend to have more vivid coloration. As is the case with Sulcatas, shell shape is a great way to determine the sex of many other tortoise species too.
Tortoise shells are made of two halves, which are sandwiched together to hold the tortoiseās body inside. The top part of the shell is called the ācarapaceā whilst the underneath of the shell is called the āplastronā. Typically, males have an indented or concave plastron, which allows them to fit over the convex shell of a female during mating. Females have flatter or even slightly convex plastrons, which provides more internal room for growing eggs.
Other Physical Characteristics
Aside from these secondary sexual characteristics that develop with maturity, male and female Sulcata tortoises are mostly identical on the outside.
Table: Physical Characteristics of Male vs Female Sulcata Tortoises
| Characteristic | Male Sulcata Tortoise | Female Sulcata Tortoise |
|---|---|---|
| Size | Larger, up to 30 inches and 220 pounds | Smaller, up to 18 inches and 130 pounds |
| Weight | at least 120 pounds on average | typically between 65 and 75 pounds |
| Tail | Longer and wider with a spur | Shorter and blunt |
| Plastron | Concave | Flatter |
| Anal Scutes | Broad, forming a wide āVā shape | More circular, forming a āUā shape |
| Gular Scutes | More pronounced and longer | Less pronounced |
| Coloration | More vivid | Less vivid |
Behavioral Indicators
It is hard to tell male spurred tortoises from females by appearance alone when they are born and while they are young, but certain behavior is evident from an early age. While both males and females fight, males are much more aggressive, even from birth. When one tortoise attacks another, they are almost always males. Sometimes, one male tortoise will mount another male just to show dominance.
Like all tortoise species, male Sulcatas become very aggressive during mating season. Such behaviors can be used to easily distinguish the sexes. Due to heightened aggression, males will often fight other males over females, attempting to flip one another over.
Males will court females by bobbing his head at her, nipping and biting at her legs and the edges of her shell and even ramming into her. Females receiving this courtship behavior will pull her head and limbs into her shell, allowing the male to mount. The act of intercourse is often very loud, with males vocalizing.
Sulcata Tortoise Breeding Ritual
A āgravidāor egg-bearing female will exhibit nesting behaviors, which is another way you can identify the sex of your tortoises. Once a suitable nesting site has been chosen, females will use their hind legs to begin to dig a nest. After 60-90 days, the female will lay her eggs in the nest. You can observe her extending her head and neck fully and then pulling it back into the shell with the effort of pushing the eggs out. Female tortoises can lay 15 to 30 eggs per clutch between 2 and 5 times a year. After the eggs have been laid, she will cover them over with soil. Like many tortoise species, female Sulcatas provide no maternal care.
When the weather is very cold or very hot, grooved or sulcata tortoises are inactive and tend to tuck themselves into their burrow, which can be up to 10 feet deep. They become active again during rainy seasons. Typically, males and females mate during the February and March rains. The gestation period, during which the female carries her eggs, lasts around 60 days, and then the female digs four or five nests before deciding which one to lay her eggs in. After laying her eggs, she covers them, and they will incubate for around eight months. A few days after a rain, the hatchlings will come out of their eggs. Although hatchlings are only 2 or 3 inches long, they can grow to be 10 inches in just a few years if they are not captured to be sold as pets.
Age and Maturity
Sulcata tortoises can live 100 years or longer in captivity. By the age of around 25, your tortoise should be full grown as far as size and weight are concerned. Every species of tortoise will reach sexual maturity at different ages, though males tend to mature slightly faster than females. For Sulcata tortoises, sexual maturity is typically reached at around 5 years of age, when shell length reaches 10 to 12 inches, and they are around 11 to 18 kg in weight.
Signs of sexual maturity are often the same signs that allow you to determine the sex. For example, physical signs include males developing longer tails and a concave plastron. Behavioral signs include females digging nests in preparation for egg laying. If your tortoise is under 4 years old, it is very difficult to determine the sex.
It's easy to distinguish between the males and females of some animals, regardless of whether they're juveniles or adults. In the case of many species of tortoises, however, sexing based on physical appearance alone isn't too realistic. Sulcata tortoises (Geochelone sulcata) are certainly no exception to this rule.
Baby Tortoise Gender
Male and female sulcata tortoises are mostly identical on the outside. It takes a while for individuals to start displaying the physical traits of their genders. When young sulcata tortoises reach roughly 12 to 14 inches long, they usually begin to develop characteristics associated either with males or females. They typically attain this length when they're around 3 to 4 years old.
Once sulcata tortoises are old enough, you can make the effort to pinpoint their sexes simply by looking at them. Boy sulcata tortoises usually have wider and more elongated tails. Female sulcata tortoises' tails tend to be a little less conspicuous.
Tortoises' anal notches are situated between their anal scutes. Male and female sulcata tortoises' notches don't look exactly the same. Those of females are markedly more circular in outline, which makes depositing eggs simpler. The males' anal scutes tend to be broader.
Veterinary Analysis for Gender Determination in Babies
You can't really discern between male and female tortoises using your eyes until they get to a certain size or age. Not even experienced veterinarians can make the call merely by looking. Exotic veterinarians can often pinpoint the sexes of young sulcata tortoises via endoscopy.
