At the foot of the hills surrounding the city of Arezzo, in the southern part of the city, where Val di Chiana begins, natural populations of Testudo hermanni hermanni currently live among ancient olive groves blessed by a mild and sunny climate for most of the year. In these ideal conditions, the tortoises live in the outdoor throughout the year in large, fenced lawns that resemble their natural habitat.
The breeding centre
Tortoises are accommodated outdoors during the whole year. However, in order to allow a natural breeding process, at the time of egg laying females are moved in large cold greenhouses, or in fenced, mesh-protected yards with suitable substrate where, protected from extreme weather conditions or predators, they can lay eggs in a suitable environment for them to develop healthily. This procedure not only avoids unnecessary delays in the egg laying activity and allows natural hatching even without artificial incubation but involves additional benefits as well. In fact, baby tortoises are usually an easy prey for many animals and despite the high fences, we still have to cope with several birds of prey, such as crows and magpies, which systematically dig up the eggs from the ground.
Even when artificial incubation is needed, we make use of the most powerful, state-of-the-art techniques available, reproducing the climate that the eggs would have in the ground through a sophisticated control and management system. We achieved this extraordinary result through accurate observation and data collection related to nests temperature and humidity throughout the breeding season and we have compared them to the hatching success, hatchlings’ vitality and sex ratio. Then we developed a monitoring station that would allow the timely and faithful reproduction of several daily cycles that proved ideal.
Top hygiene conditions and disease prevention of our tortoise are paramount. All the animals are kept in very large fences measuring up to more than 200 square meters, with natural substrate, that we maintain adequately populated. Overpopulation, in fact, frequently causes the spread of several, often disastrous, diseases: consequently, each species and subspecies as well as the hatchlings are raised separately, minimizing the spread of disease and parasites. Thanks to this smart approach, our animals stay healthy and the use of medications is very limited. Finally, the number of breeders and the careful selection of matings between unrelated subjects, guarantees the reared animals highest profile.
testudoalbino professional breeding of Mediterranean tortoises
For many years, I have picked up and developed in an incubator part of the eggs laid at the beginning of the season, which had fewer opportunities to develop due to possible climate resurgence. Today, as back then, we rely upon devices suited to maintain a constant temperature, which unofortunately feature thermostats often inaccurate as well as approximate temperature check. Hatching percentage can also vary greatly from year to year, as it is not always possible to obtain even an accurate humidity control. Luckily, tortoises’ eggs have a wide enough tolerance, so that they can develop in a quite varied temperatures and humidity range that ensure a normally acceptable hatching. Over time I noticed that ground-born animals, even at the end of the summer season and beyond, showed a decidedly higher survival rate compared to specimens born early in incubators maintained at a constant temperature. As a biologist, I was prompted to made in-depth researches in the huge scientific literature concerning tortoises. Soon I found a few articles published on international scientific journals, which associated several incubation parameters with lack of development, morphology, adaptation to the environment (fitness) and, definitely, of survival. I spent a whole year collecting data related to incubation temperature starting from the month of April until October and then I compared them to hatching success and newborns’ viabilty upon birth. It was obvious how a particular temperature development would be such as to ensure the highest percentage of hatching and fully-formed, large and thriving newborns. In such conditions – although I could only check it later - it was also observed a fairly balanced relationship between genders, which has never been obtained by incubating eggs at constant temperature. Even if we usually consider the incubation temperatures average as crucial for the development of a gender or another, the nest temperature fluctuating within the optimal range for the various species, ensures the birth of babies of both sexes. It should be emphasized that inside the nest we always find a temperature gradient and therefore not all the eggs will be in identical conditions. Initially, I decided to build an incubator that could ensure two different temperatures during night and day. This was quite before similar devices were introduced in the market, but it was soon clear that it was virtually impossible to artificially reproduce what happens on the ground, i.e. a linear and progressive progression, quite different from the sudden changes induced by this type of solution. Even if it should be noted that the newborns fitness upon birth was much improved, a significant difference compared to specimens born in ground still remained. The solution was to develop a thermohygrostat suitable to adjust the temperature each hour on the basis of a program reproducing the best incubation conditions detected in nature. Beside varying the temperature and thus gradually minimizing thermal shocks, this instrument should ensure an advanced temperature and humidity control, such as to get in any moment parameters set. This feature was obtained by including a function activating a cooling system that lowered the temperature exceeding a certain threshold compared to the one currently set. Since humidity is a basic parameter in a proper incubation context, a system was activated to promote the relative humidity increase, while another was included in order to avoid its excess. In fact, while in the ground the soil maintains a level of relative, fairly constant humidity in the nest chamber, regardless of the current temperatures, in the incubator’s enclosed and hermetic environment, the air ability to absorb humidity varies depending on temperature, thus causing dangerous, sudden changes. However, this is not the whole story, because eggs’ active metabolism further changes this parameter, so that sometimes a function that lifts humidity from the air through a dehumidifier is required. In fact, if humidity rises beyond a certain limit that is specific for each species based on particular environmental adaptations, can cause the embryo’s death.
This ultimately allows eggs not only to develop in the best conditions found in nature, but ensures a natural and balanced gender determination without external contrivance, so as to curb the sexual inversion phenomenon, i.e. a phenotypic sex different from the genetic one, which is also associated to a reduction of fitness and even of average survival. This is certainly not a parameter to be underestimated, since our tortoises are expected to lead a long and healthy life.
testudoalbino professional breeding of Mediterranean tortoises