Habitat climate in pictures
In my book "Natural keeping and breeding of the Greek tortoise" I have already dealt in great detail with the Mediterranean climate, the habitat climate and the difference between climate diagrams and the microclimate in which the tortoises live in their heat islands.
Because pictures not only have much more expressiveness, but are also more likely to be remembered than Texts, I took some pictures of this on a sunny, partly cloudy day in mid-May 2009.
I measured the temperatures with an electronic digital thermometer with a thermocouple.
The habitat is located in a Greek hilly landscape about 25 km as the crow flies from the sea at an altitude of about 250 m above sea level.
As is common in large parts of Greece including the Peloponnese, Testudo hermanni boettgeri and Testudo marginata occur directly next to each other in the same area.
A view over this wide hill country. The barren, stony and rocky area is unsuitable for agriculture and, apart from the deforestation, was obviously not used by humans in earlier years. However, it is grazing land. Shepherds regularly lead herds of sheep and goats over the hills to graze on the grass and bushes.
I have never met hunters there. The shot shells usually lying around in many other habitats are also not available. Hikers certainly do not get lost in this hilly country, which is far from the usual tourism. Fires are extremely rare here and, due to the low bush vegetation, without the dry wood and tall withered grass that would otherwise be lying around in habitats, they cannot spread and go out by themselves.
Even in this hilly country the turtles are not found everywhere. In addition to a few other criteria, the climate must also be right. What is needed, however, is not the mesoclimate prevailing in the open landscape, but the microclimate in the immediate vicinity of the ground in which the turtles also live. This turtle-friendly microclimate can only be achieved in sheltered, sunny locations. Original, halfway natural turtle habitats are heat islands with their own very special microclimate.
The whole area is covered with many rock formations and stones.
Due to the sheltered location between the rocks and the bush formations, the actual ground surface is not touched by the constantly blowing wind in the area. The otherwise usual mixing effect of the various layers of air is not present here. Within the heat islands, there is only slight air movement and no more air movements directly above the ground.
Due to the many rock formations and boulders lying on top of each other, there are relatively many small caves that are regularly used as shelter by the turtles.
The circles show the following three measuring ranges at 2:30 p.m.
1 In the sun between rocks and bush formations in the vegetation that is only a few centimeters high.
2 In the shade a few centimeters inside the bush, directly on the ground.
3 A few centimeters inside the relatively low cave, which is more than a meter deep.
First, however, the air temperature in the sun at a height of about 2 meters above the ground: 27.3 ° C.
For comparison, the average temperature for this area is given as 19 ° C in May.
The thermometer is already rising in the scorching sun between the vegetation, which is only a few centimeters high 48.6 ° C.
Inside the bush, 28.7 ° C was measured in the shade, 1.4 degrees more than in the sun at a height of 2 meters.
The temperature in the cave is a pleasant 19.5 ° C.
The surface temperature measured directly on the carapace is 39.8 ° C with this actively moving Marginata.
The same turtle with a cloaca temperature of 33.7 ° C. Years ago I determined a preferred cloaca temperature of around 35 ° C from a number of previous measurements.
At this point I would like to make another fundamental point. As I have already done in my book "Sardinia, the island of European tortoises" and in my book " European tortoises, habitat and way of life" wrote is the Field herpetology is always an intervention in nature. Investigations on protected wild animals are now usually subject to approval and should by “laypeople” for private purposes. Should you ever be lucky enough to encounter a turtle in its natural environment during a vacation trip, please leave it at that to observe the animal or to take pictures as you have encountered it. A wild animal that is picked up from the ground suffers a shock and empties the entire contents of the intestines and bladder due to the sheer stress. However, since this also serves to regulate the water balance in turtles, this can mean the death sentence for the animal, especially in the hot summer months. In all my studies on the turtles, I always made sure that I carried out all "interventions" such as taking photos, measuring weight, length and temperature as well as taking blood and tissue samples as gently as possible.
What I always do it was considered that the water balance of these animals was back in balance. For this purpose, I always carried a container and water with me and had corresponding animals like this small Marginata in a sand dune take in water. All of these turtles have made extensive use of it on a regular basis.
Finally, the temperature at 6:30 a.m.: 19.2 ° C at about 2 meters above the ground.
What is interesting, however, is the temperature on the surface of the ground at this time: 14.7 ° C. That results a day / night temperature gradient of 34 ° C.
Think about the temperature gradient you offer your turtles.
Here is a hopefully informative shot of my shoes. As you can easily see, they only got really wet at 06:30 in the two previous recordings. The soil, including the vegetation close to the ground, and thus also the turtles living in it, are extremely moist, at least in the early morning hours. The moisture is dried relatively quickly by the rising sun and also provides moist air which, due to the lack of air movement, lies like a bell over the heat island during the day. In any case, the humidity in the Mediterranean region is much higher than here.
