No matter what tortoise species you maintain, you’re going to need to be patient. Tortoises grow very slowly.
But while this can often frustrate their keepers, it means that tortoises also live very long lives. These aren’t pets that’ll die after a year or two; most tortoises will have lifespans that measure in decades.
All of this holds true for the Hermann’s tortoise (Testudo hermanni) – one of the most popular species among modern tortoise keepers. Keep reading to learn all about their lifespan and growth rate so that you can know what to expect from your pet.
The Hermann’s Tortoise: Factors Influencing Growth
Tortoises don’t do anything quickly. They’re famous for their slow walking speed, but they also grow remarkably slowly. Nevertheless, individual Hermann’s tortoises exhibit a range of growth rates, with some growing much more quickly than others. A few of the factors that influence the growth rate of an individual tortoise include:
- Subspecies: There are two species of Hermann’s tortoise, and they differ in size. The eastern Hermann’s tortoise (T. h. boettgeri) is the larger of the two, and some individuals reach or exceed 11 inches in length. Meanwhile, the western Hermann’s tortoise (T. h. hermanni) remains smaller and rarely exceeds 7 inches in length.
- Sex: Hermann’s tortoises are known as a sexually dimorphic species with respect to size. Specifically, female Hermann’s tortoises reach larger sizes than males. This is most pronounced in the eastern subspecies, as mature females are often 9 to 11 inches in length, while eastern males rarely exceed 6 inches.
- Diet: Tortoises who’re fed more food or offered better quality diets may grow more quickly. Diets that are high in protein will generate especially rapid growth, but this typically causes serious health problems and is therefore strongly discouraged.
- Husbandry: The quality of care a tortoise is provided with will often influence its growth rate. Tortoises who have an adequate enclosure with access to proper temperatures and humidity levels, a suitable substrate, and plenty of hiding opportunities to keep their stress level low will grow more quickly than tortoises provided with suboptimal environmental conditions.
- Illness: Illnesses will cause a tortoise to allocate energy toward fighting off the illness rather than growth. So, tortoises who suffer from serious illness will often grow more slowly than those who remain healthy. Such tortoises may even fail to grow as large as tortoises who remain healthy their entire lives.
- Individual Variation: There are innate individual differences between the growth rates of different individual tortoises. It is likely, though not known for certain, that rapidly growing tortoises will have offspring that also tend to grow rapidly.
Growth Stages of the Hermann’s Tortoise
Hermann’s tortoises don’t exhibit distinct life stages or growth stages in the way some invertebrates do, and they tend to grow in a relatively gradual fashion. However, their growth can be divided into four different time periods.
Hatchlings (0 to 12 Months)
Hermann’s tortoises – like almost all tortoise species – grow most rapidly during the first year of their life (relative to their body size). Most Hermann’s tortoises will reach about 2 to 3 inches in length by the end of their first year of life, which may represent a three-fold increase in length. Some may reach or exceed the 80-gram mark by the time they reach their first birthday.
Juveniles (12 to 36 Months of Age)
Hermann’s tortoises continue to grow quite quickly during the next one to three years. By their third birthday, many Hermann’s tortoises will have reached 3 to 4 inches in length and weigh 200 grams or more.
Young Adulthood (48 to 72 Months of Age)
As they approach maturity, Hermann’s tortoises begin exhibiting a slower growth rate. They also begin to increase in weight more than they increase in length. By the time they’re five years old, many Hermann’s tortoises measure 5 to 6 inches in length, though some may be longer (particularly those belonging to the eastern subspecies) or shorter than this.
The weight of tortoises in this age range will vary, but most should be at least 500 grams or so by their fifth birthday. Large specimens measuring 7 inches in length of more may weigh 1 kilogram.
Mature Adults (More Than 72 Months of Age)
By the time they’ve reached reproductive maturity, many Hermann’s tortoises essentially stop growing. They may technically continue to increase their length or weight over time, but most of the calories they consume by this time are allocated to maintenance or reproduction.
In fact, when tracking the weight of mature Hermann’s tortoises, keepers should strive to maintain their pets’ weight or observe a very slow and consistent rate of growth.
Lifespan of the Hermann’s Tortoise
All tortoises live relatively long lives, and Hermann’s tortoises are no exception. In fact, they have to in order to survive as a species.
Hermann’s tortoises produce relatively few young each year (perhaps three to five), and there are likely years in which a given female fails to produce an egg clutch at all. And of these, a significant percentage die at the hands of predators before reaching maturity.
Accordingly, the only way for the species to survive over the long term is by living for many decades, which gives the females a chance to produce enough eggs to ensure the next generation survives to adulthood.
But unfortunately, while we know that Hermann’s tortoises live long lives, there hasn’t been a lot of systematic research conducted to provide more specific information. Instead, most of what we know about Hermann’s tortoise lifespan is based on anecdotal accounts.
It is also possible to make some broad predictions, based on what we know about other tortoise species. For example, other species in the genus Testudo have been documented reaching 120 years of age, so Hermann’s tortoises are likely capable of reaching similar ages.
With all that said, most authorities agree that Hermann’s tortoises likely live for about 50 to 100 years, although there are undoubtedly outliers at both ends of this spectrum. There are anecdotal accounts of a Hermann’s tortoise from the UK who lived to be 110 years, but well-documented reports of such an individual are hard to find.
Citations
- Animal Diversity Web – Testudo hermanni
- Exotic Keeper Magazine – Care Guide: Hermann’s Tortoise (Testudo Hermanni)
- Tortoise Town – Hermann’s Tortoise Lifespan
