Wide-brimmed tortoise
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Wide-brimmed tortoise ( Testudo marginata ) |
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| Schoepf , 1792 |
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The wide-brimmed tortoise ( Testudo marginata Schoepf , 1792) is the largest of the five tortoise species within the genus Testudo (Palearctic tortoises). Wild animals in some regions reach armor lengths (SCL, height) of up to 34 cm; but there are also small populations with about 20 cm carapace length. The distribution area is now limited to the southern Balkan peninsula and some Aegean islands. Occurrences in Sardinia and mainland Italy are considered naturalized by human hands. The species has various local forms, but no real subspecies .
description
This tortoise species has an elongated back armor, waisted in the middle, the rear edge shields of which - especially in older, male animals - are wide exposed, sometimes also arched and sawn. The basic color of the back armor in adults is black with lighter spots in the vertebral and costal shields. The horn-yellow belly armor has characteristic, paired, dark triangular spots, the tips of which are directed backwards. The fronts of the front legs are covered with large, tile-like overlapping scales. In older animals, the rear lobe of the belly shell ( plastron ) is somewhat mobile. There is an elongated marking on the tail. The animals have approaches of thigh spurs, but no horn nail on the tail. Depending on the local form, the animals can reach shell lengths of up to 34 cm, and even up to 40 cm when kept in captivity.
Young animals differ from sexually mature animals in their shell shape and color. The armor is more rounded, the widening of the rear edge shields is still missing. The bright carapace shields of the hatchlings get a horseshoe-shaped, dark border as a result of the horn growth, which becomes wider and wider over time and leads to the characteristic image of almost black turtles with light central spots.
The species has a pronounced sexual dimorphism . What is unusual for the genus Testudo is that male wide-brimmed turtles are larger than females. The broad edge that gives them their name is more pronounced, they are even more elongated and tapered. In addition, like other Testudo species, they also have a longer tail, thicker at the base, and a clearly concave belly armor.
Geographical variations
The wide-brimmed turtle Testudo marginata is relatively variable in appearance despite its small distribution area. This led to multiple attempts to separate certain local forms as subspecies or even independent species based on their morphological criteria. In 1992 Mayer described the wide-brimmed turtles of Sardinia as a separate subspecies Testudo marginata sarda , because their rear marginal shields are less jagged and not as protruding as in the Greek form, which is particularly noticeable in adult males. This classification is not tenable, however, because the Sardinian animals were introduced by human hands and this local form is too young to be able to form a genetically independent subspecies. The undisputed differences in armor shape are probably the maintenance of youth forms. Certain Greek local forms also differ in shell shape and size from other populations, which prompted Bour in 1995 to designate them as a separate species, Testudo weissingeri . However, studies have shown that the animals hardly differ genetically, so that their smaller size is attributed to barren environmental conditions.
distribution
The natural occurrence of the wide-brimmed turtle is southern Greece from the Peloponnese to Olympus and the adjacent southern Albania. There are also small, island-like occurrences on the Aegean islands Skyros and Poros . The wide-brimmed turtle is naturalized in some regions of Italy. These include the occurrences in the northeast of Sardinia and an isolated population at Tombolo Livorno , Tuscany . An alleged occurrence near Ephesus in Turkey is apparently based on individual sightings of abducted specimens.
Way of life
The wide-brimmed tortoise is more at home in mountainous habitats than the Greek tortoise ( Testudo hermanni ). She lives at heights of up to 1600 meters. The animals benefit from the dark color of the back armor, which enables them to absorb a lot of heat in a short time, in order to reach the necessary body temperature . The fairly light underside, in turn, prevents heat from being radiated onto the cold ground. At the same time, the massive body can store the heat for a long time. The main food is the plants in the meadows of their Mediterranean home. In the early morning they leave their night shelter and let the sun warm them up first. Then they go to their feeding places. In principle, animals are herbivores, but animal protein is not spurned, especially when there is a lack of food, this is especially true for young animals and pregnant females. So every now and then earthworms and snails are ingested. They spend the hot lunchtime in their hiding spots, which they usually only leave in the late afternoon.
Reproduction
Immediately after waking up from the cold rigor , the mating instinct sets in. The males pursue the females with great zeal, circle them, bite them in the limbs, ram them with violent thrusts and try to ride them up. In intermittent copulation , the male opens its mouth, the red tongue becomes visible, and it emits cries that can be heard from far away. They sound almost sighing in long, deep tones, in contrast to the Moorish tortoise , where a high-pitched intermittent beeping can be heard. During mating, the female will stand still with her head up sideways so that she can see the male's wide open mouth. Obviously the red tongue has a signaling function. In the same rhythm as the male makes his sounds, the female moves his head left and right.
If the female has found the right place after a long search, she remains still and braces her front legs firmly into the ground. It now begins to dig a cave with its hind legs. The feet work alternately between left and right, at first more scraping, then really digging and shoveling. Soon two piles of loose soil are formed. The size of the cave is determined by the length of the rear legs. If the earth is too hard, the female drains water from the anal bladder to soften it. After the digging, the egg-laying begins. Each egg is gently rolled backwards. After the last egg, the female immediately begins to shovel, again alternating with the hind legs. Finally, she stamps the earth with her feet. This gives the floor its natural strength again. Large animals can lay up to three clutches of 15 eggs each in one summer.
The breeding season in natural conditions is about 100 days. That is relatively short. In many tropical turtles, it lasts up to 200 days. The relatively short time is an adaptation to the subtropical Mediterranean climate with the not indefinitely long summers. The incubation time in the incubator is significantly shorter. At a continuous temperature of 31.5 degrees Celsius, wide-brimmed turtles hatch after just 60 days.
After the sixty days of embryonic development in the egg the young animal scratches first with the egg tooth , the shell from the inside, pushing the egg tooth an opening out and can now for the first time, the lungs fill with air. Then it withdraws again, turns in the egg, continues to work the shell with the egg tooth and then folds the egg open. In nature, the animal remains in the ground for the first two weeks. Here it is safe from enemies and still grows because it feeds on the yolk sac that has moved in. The young live very hidden, mostly they stay in the shade, they avoid the sun, because the danger of overheating is great. Little is known about the growth of wide-brimmed tortoises in nature; information on growth rates is only available from captivity. From sexual maturity, the weight gain is minimal. In captivity, the animals can reach an old age of up to 100 years, no information from nature is available.
Protection status
Like all real tortoises, the wide-brimmed tortoise is protected by the Washington Convention . It is listed in CITES Appendix II or Appendix A of the EU Species Protection Ordinance . According to the Federal Species Protection Ordinance in the Federal Republic of Germany, their keeping is notifiable.
The broadband turtle is listed by the European Union in Annexes II and IV of the Habitats Directive and is therefore a species of community interest to be strictly protected, for whose preservation special protected areas must be designated by the member states.
proof
Individual evidence
- ^ Uwe Fritz, Peter Havas: Checklist of Chelonians of the World. (PDF; 925 kB) In: Vertebrate Zoology. 57 (2), Dresden 2007.
- ↑ H. Bringsoe, J. Buskirk, RE Willemsen: Testudo marginata SCHOEPFF, 1792 - wide-rimed tortoise. In: Uwe Fritz (Ed.): Handbook of Reptiles and Amphibians in Europe. Volume 3: Tortoises (Testudines) 1. Aula, Wiebelsheim 2001, ISBN 3-89104-004-0 .
- ↑ U. Fritz, G. Peters, W. Matzanke, M. Matzanke: To the tortoise fauna of Northern Sardinia. Part 1. In: herpetofaua. 17 (99) 1995.
- ↑ U. Fritz, P. Siroky, H. Kami, M. Wink: Environmentally caused dwarfism or a valid species - Is Testudo weissingeri Bour, 1996 a distinct evolutionary lineage? New evidence from mitochondrial and nuclear genomic markers. In: Molecular Phylogenetics and Evolution. 37 (2) 2005, pp. 389-401.
- ↑ CITES Species database
- ↑ DGHT database of protected amphibians and reptiles ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
literature
- H. Bringsoe, J. Buskirk, RE Willemsen: Testudo marginata SCHOEPFF, 1792 - Wide-brimmed tortoise. In: Uwe Fritz (Ed.): Handbook of Reptiles and Amphibians in Europe. Volume 3: Tortoises (Testudines) 1. Aula, Wiebelsheim 2001, ISBN 3-89104-004-0 .
- M. Herz: Observations on wide-brimmed tortoises Testudo marginata SCHOEPFF, 1792 in the wild. In: Sauria. 16 (1) 1994, pp. 27-30.
- PF Keymar, H. Weissinger: Distribution, morphological variation and status of Testudo marginata in Greece. - Proceedings of the 4th Ordinary General Meeting of the Societas Europaea Herpetologica. Pp. 219-222.
- M. Mähn N. Graf: On the reproductive biology of European tortoises using the example of the wide-brimmed tortoise (Testudo marginata, SCHOEPFF 1792). In: Mediterranean tortoises. (Draco 2). Natur-und-Tier-Verlag, Münster 2000, DNB 959186042 , pp. 32-41.
- R. Praschag: tortoises , Verlag Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3546-9 .
- M. Rogner: Tortoises - biology, keeping, reproduction. Verlag Eugen Ulmer, Stuttgart 2008, ISBN 978-3-8001-5440-1 .
- W. Wegehaupt: The Sardinian population of the wide-brimmed tortoise (Testudo marginata SCHOEPFF, 1792). In: Marginata. January 1, 2004, pp. 24-30.
Web links
- Photos of the wide-brimmed turtle on www.herp.it
- Testudo marginata in The Reptile Database
- Testudo marginata inthe IUCN Red List of Threatened Species 2013.1. Posted by: van Dijk, PP, Lymberakis, P. & Böhme, W., 2004. Retrieved October 13, 2013.
- Species protection project