Palearctic tortoises

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Palearctic tortoises
* left: Testudo graeca ibera, * above: Testudo hermanni boettgeri, * right: Testudo hermanni hermanni, * below: Testudo marginata
  • left: Testudo graeca ibera ,
  • above: Testudo hermanni boettgeri ,
  • right: Testudo hermanni hermanni ,
  • below: Testudo marginata
Systematics
without rank: Sauropsida
Order : Turtles (Testudinata)
Subordination : Halsberger tortoises (Cryptodira)
Family : Tortoises (Testudinidae)
Subfamily : Testudininae
Genre : Palearctic tortoises
Scientific name
Testudo
Linnaeus , 1758

The representatives of the genus Testudo are referred to in German as palaearctic tortoises , real tortoises or, colloquially, European tortoises . The latter is wrong insofar as the species of the genus Testudo are not only native to Europe, but also to western Asia and northern Africa. The Palearctic summarizes these land masses.

The term "Mediterranean tortoises", however, does not represent a genus of its own, but is a purely geographical and climatic grouping. The species belonging to this grouping occur in similar habitats and are subject to comparable living conditions there, but all belong to the genus Testudo .

The affiliation of individual species and subspecies to the genus Testudo was partly questioned ( Testudo horsfieldi , Testudo hermanni , Testudo graeca nabeulensis ). The relationship within the genus has not yet been sufficiently researched, but nature hybrids in sympathetic zones and hybrid forms under captivity have been described several times.

Appearance

The mean height of the back armor of adult Palearctic tortoises varies between less than 10 centimeters in male Egyptian tortoises and up to 40 centimeters in wide-edged tortoises . The back armor is slightly elliptical in shape and usually two-colored; Typical, darker drawing elements can be found on a yellowish to pale orange, brown or olive green base tone. In the case of the Egyptian tortoise, however, the dark color markings can be so slight that they appear almost monotonously sand-colored. The plastron posterior flap is movable in some species, but the armor on the back has no joint. The genus shows a pronounced sexual dimorphism with thicker tail bases and concave belly armor in males.

Reproduction

The mating behavior of the Palearctic tortoise is rough. The males persistently pursue the females and often ram or bite them before mating. Clutches comprise an average of 4–6 eggs, fewer in Egyptian tortoises and sometimes more in older females of the larger species. Multiple egg-laying per season is also possible.

The time between egg laying and hatching of the young turtles depends on the nesting temperature. Under natural conditions it is usually 80–115 days, and sometimes even more, depending on the weather. In contrast, with artificial incubation at consistently high temperatures, some Testudo young hatch after approx. 55 days. Under natural conditions, they need at least 8–12 years to reach sexual maturity, sometimes even significantly longer.

Duration

Each of the turtles belonging to this genus is at least regionally threatened. In addition to habitat destruction, the catch for the animal trade also contributes to this. This applies in particular to the Egyptian tortoise, which people consider "cute" because of their small size, and which probably no longer occurs in Egypt. The species, which is difficult to care for, is classified as endangered by the IUCN . The four-toed tortoise is similarly endangered . According to a study, there are still a few regions in Kazakhstan that could cope with a population loss of 40,000 animals annually. In fact, 150,000 animals were caught and traded here every year at the beginning of the 1990s.

Distribution areas of the five Testudo species

species

The genus Testudo includes:

The Tunisian tortoise Testudo nabeulensis , the dwarf wide-edged tortoise Testudo weissingeri and the Dalmatian tortoise Testudo hercegovinensis , on the other hand, are not to be regarded as separate species.

literature

  • Uwe Fritz : Handbook of the reptiles and amphibians of Europe. Turtles (Testudines) I . Aula Verlag, Wiebelsheim 2001, ISBN 3-89104-004-0 .
  • Reiner Praschag: tortoises , Verlag Eugen Ulmer, Stuttgart 2002, ISBN 3-8001-3546-9 .
  • Manfred Rogner: Tortoises - biology, keeping, reproduction , Eugen Ulmer Verlag, Stuttgart 2008, ISBN 978-3-8001-5440-1 .
  • Richard Gary Paull: The small and medium sized tortoises , Green Nature Books, Homestead 1997, ISBN 1-888089-25-3 .

Individual evidence

  1. ↑ a b c Uwe Fritz: Handbook of the reptiles and amphibians in Europe. Tortoises (Testudines) I. Aula Verlag, Wiebelsheim 2001, ISBN 3-89104-004-0 .
  2. ↑ D. Müller: Mediterranean tortoises - biology, husbandry, reproduction, disease Mittenaar 2011.
  3. ↑ LI Khozatsky, M. Mlynarski: Agrionemys - nouveau genre de tortues terrestres (Testudinidae). In: Bull. Acad. Polon. Sci. Cl. II, 14, No. 2, 1966, pp. 123-125.
  4. ↑ F. de Lapparent de Broin, R. Bour, JF Parham, J. Perälä: Eurotestudo, a new genus for the species Testudo hermanni Gmelin, 1789 (Chelonii, Testudinidae). In: Comptes Rendus Palevol 5, No. 6, 2006, pp. 803-811.
  5. ^ AC Highfield: Tortoises of North Africa: Taxonomy, nomenclature, phylogeny, and evolution with notes on field studies in Tunisia. In: J. Chelon. Herpetol. 1, No. 2, 1990, pp. 1-56.
  6. ↑ Paull, p. 162.
  7. ↑ Rogner, pp. 95 and 93.
  8. ↑ Paull, p. 163.
  9. ↑ Paull, p. 160.
  10. ↑ Uwe Fritz, Peter Havas: Checklist of chelonians of the world (PDF; 925 kB, compiled for the CITES Nomenclature Committee and the Federal Agency for Nature Conservation) In: Vertebrate Zoology 57, No. 2, 2007.

Web links

Commons : Testudo  - collection of images, videos and audio files