Eastern green lizard

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Eastern green lizard
Eastern green lizard (Lacerta viridis), female (front) and male (background) in the Pilis Mountains, Hungary

Eastern green lizard ( Lacerta viridis ), female (front) and male (background) in the Pilis Mountains, Hungary

Systematics
Superordinate : Scale lizards (Lepidosauria)
Order : Scale reptiles (Squamata)
Family : Real lizards (Lacertidae)
Subfamily : Lacertinae
Genre : Lacerta
Type : Eastern green lizard
Scientific name
Lacerta viridis
( Laurenti , 1768)

The Eastern Green Lizard ( Lacerta viridis ) is a large European lizard species with a green basic color. Only with the proof of insufficient cross-ability and after further comparative genetic studies has it been recognized since around 1991 that there is another species that also occurs in Central Europe , the western green lizard ( Lacerta bilineata ). Previously, these species had not been differentiated, although there had been hints and efforts to do so earlier.

features

A female animal
Cub

It is a large, but quite slender-looking lizard with a pointed head and a tail that is quite long, especially in the case of the males. Its dimensions can be 1.6 to 2.3 times the length of the head and torso, which is up to 13 centimeters. The maximum total length is often difficult to quantify, however, as many older animals no longer have an intact tail, but have lost it and (incompletely) regenerated it in the meantime in contact with predators or in mating fights. However, a total length of about 40 centimeters is achieved. The extremities are relatively long in relation to the trunk.

The back and large parts of the body are light to dark green in both sexes. The green color arises only gradually in the course of the first years of life; the young show brown tones. While the somewhat more robust-looking, larger-headed males usually have small black, sometimes ornament-like speckles on the green base color, the females often have a drawing pattern with rows of dark markings and whitish-yellow lines that can merge into longitudinal bands. However, depending on the region and season, the sexes cannot always be differentiated by means of drawing features. The abdomen and throat are spotlessly white, greenish or yellow in color. With the first moult after hibernation, the chin, throat and throat regions turn green-blue to "cornflower blue" in both males and partially in females. This “mating dress” appears richer in contrast and color in the male.

The above description also applies to the sister species, the western green lizard . Morphologically, there are only minor differences in the scaling and body proportions between the two species. Apart from genetic characteristics, the two species are mainly differentiated by their different distribution. Occasionally, an emerald lizard can also be confused with a male sand lizard ( Lacerta agilis ).

habitat

Green lizards prefer sun-warmed, south / south-west / south-east exposed slopes with a sufficient degree of moisture and a mixture of open structures and mosaic-like vegetation. Are particularly suitable, for example, drier forest margins, grassy vineyards , semi-dry grasslands (but not loose bushes dry grass !), Broom - and heathland , thickets of brambles, rail and Wegdämme, meadows with Schlehengebüschen and sparse orchards . In the south of the distribution area, on the other hand, the occurrences are often limited to humid locations or to mountainous regions. The diurnal animals take extensive sunbaths in the morning and in the evening; otherwise they climb around in the vegetation looking for food. In case of danger, they scurry very quickly into protective vegetation as well as crevices and hollows.

Reproduction

(Note: phenological data refer to Central Europe.)

Adolescent emerald lizard from the Kaiserstuhl

After about six months of wintering in frost-proof burrows in the ground, the males appear first in March or April, then the females and finally in May the young animals appear on the surface. First of all, warming up in sunlight is in the foreground for cold-blooded animals . After molting, mating activities begin in May. The individuals claim territories , which the males defend against each other in fierce battles with imposing behavior , biting and chases. They show typical courtship behavior with certain movement patterns towards females . When mating, the male first bites the tail of the female running in front of him; both continue in the so-called mating march. It then bites its flanks, bends its lower body under the female, and inserts its hemipenis into the female's cloaca . The copulation takes several minutes. A female mates with several males and vice versa on occasion.

After about three to six weeks, the females lay 6 to 23 eggs, initially about one centimeter wide. The eggs are laid at night in probably self-dug burrows that are about 30 centimeters long and about ten centimeters below the surface. After that, the females often guard and defend the clutch for a few days - also against other females.

The development of the eggs (egg fermentation) takes about 70 to 100 days depending on the ambient temperature. By absorbing water, their initial volume increases by about a third. The hatchlings are already eight to ten centimeters long. Sexual maturity occurs at just under two years of age and the lizards, which have grown rapidly until then, slow down their further growth. A life expectancy of ten to twelve years is assumed.

Food, predators

Green lizards eat larger insects , spiders , woodlice , snails and small vertebrates (e.g. young mice), but also reptile eggs and young animals as well as berries. They actively hunt prey with the help of their visual and olfactory senses, grab their prey with their toothed mouth and swallow them directly or after chewing them several times. Bulky parts such as the hard wing covers of insects are removed beforehand by shaking.

They themselves are part of the prey spectrum of snakes (for example, often syntopically occurring smooth snake ), birds of prey and nine killers . Chickens mainly eat the young. Among the mammals , domestic cats , shrews , hedgehogs , foxes and species of martens should be mentioned as enemies .

distribution

Distribution of the Lacerta viridis group in Europe and Asia Minor

The species, which is more south-eastern within Europe, has its western limit of distribution in Germany (see next paragraph), Austria ( Carinthia , Styria , Burgenland , Lower Austria , Upper Austria ), in Slovenia and the extreme northeast of Italy ( Trieste , Udine ); to the east, the area extends over the entire Balkan Peninsula to Ukraine and Turkey . The emerald lizard form fejervaryi , which occurs on the Italian island of Elba , is now attributed to Lacerta bilineata .

In Germany there are only a few island-like occurrences in the Danube slopes near Passau and - as a phylogeographically completely disjoint area today - in eastern Brandenburg . New DNA examinations also revealed that the emerald lizard populations at the Kaiserstuhl , which had meanwhile been regarded as Lacerta bilineata , also belong to Lacerta viridis and must be of allochthonous origin. However, in the Herpetofauna of Baden-Württemberg, which appeared a little later, it is assumed that the southern Baden emerald lizards on the Kaiserstuhl and Tuniberg belong to the species Lacerta bilineata .

Germany, Italy and Croatia are the only countries in which the two green lizard species Lacerta viridis and Lacerta bilineata occur. In the north-eastern Italian region of Friuli- Venezia Giulia , a hybridization zone of both species seems to exist; otherwise their distribution areas are largely allopatric . On the Croatian island of Cres , however, a bilineata population was able to survive, while this species was probably displaced in the rest of the Istria region by the eastern green lizard, which was spreading to the west.

Subspecies

Lineage of the green lizards ( Lacerta viridis , Lacerta bilineata ). In addition to the eastern and western green lizard, there are two other basic lineages. The Adriatic Line and the Asia Minor. The eastern green lizard can in turn be divided into three separate taxa.
  • Lacerta viridis guentherpetersi Rykena, Nettmann & Mayer, 2001
  • Lacerta viridis infrapunctata Schmidtler, 1986
  • Lacerta viridis meridionalis Cyrên, 1933
  • Lacerta viridis paphlagonica Schmidtler, 1986
  • Lacerta viridis viridis (Laurenti, 1768)

The subspecies status of L. v. infrapunctata and L. v. paphlagonica (both Turkey) is questioned by some authors.

Species formation in the Lacerta viridis bilineata complex

A male emerald lizard from the Kaiserstuhl

The formation of two biological species of green lizards was initiated by biogeographical factors. The entire area has a relatively narrow "bottleneck" south of the Alps , which restricts the exact exchange . No contiguous distribution area could develop and maintain north of the Alps after the Ice Age. Favored by this extensive spatial separation, selective evolutionary processes took place, which gradually led to genetic differentiation in the populations. This was methodically verified by comparing genetic distances of allozyme profiles and mitochondrial DNA sequences (cytochrome b). Today the development has advanced so far that crosses between individuals of Lacerta bilineata and Lacerta viridis result in very limited fertile offspring. It is assumed that speciation is currently at a "point of no return".

Danger

Green lizard in Austria, near Aschach ad Donau

Unfavorable climatic conditions and changes can lead to population losses, especially on the northern edge of the distribution area, especially in Germany. This affects more territorially isolated populations that are already weakened by other factors and poor in individuals. The island-like Brandenburg population of the Eastern Green Lizard, for example, is estimated to be less than 300 specimens. However, certain anthropogenic measures have a decisive effect in the habitats, which can generally be characterized as extensive cultural landscapes . The intensification of cultivation, the expansion of traffic routes or the encroachment or afforestation of semi-open habitats are among others. It is possible that it is captured by “lovers”, although the species is protected under the Bern Convention, among other things .

Further protection status (selection)

National red list classifications (selection)

  • Red list of the Federal Republic of Germany: 1 - critically endangered
  • Red list of Austria: EN (corresponds to: highly endangered)
  • Red list of Switzerland: (this species does not appear here)

Sources and further information

literature

  • Günter Diesener, Josef Reichholf : amphibians and reptiles (= Steinbach's natural guide. ). Mosaik-Verlag, Munich 1986, ISBN 3-570-01273-5 .
  • Kerstin Elbing: The green lizards. Two (un) same sisters (= magazine for field herpetology. Supplement 3). Laurenti-Verlag, Bielefeld 2001, ISBN 3-933066-09-3 .
  • Silke Rykena, Hans-Konrad Nettmann, Rainer Günther: Western emerald lizard - Lacerta bilineata Daudin, 1802. In: Rainer Günther (ed.): The amphibians and reptiles of Germany. Gustav Fischer, Jena et al. 1996, ISBN 3-437-35016-1 , pp. 558-566.

Individual evidence

  1. Silke Rykena: Crossing experiments to test the species boundaries in the genus Lacerta sensu stricto. In: Messages from the Museum of Natural History in Berlin. Zoological Museum and Institute for Special Zoology (Berlin). Vol. 67, No. 1, 1991, pp. 55-68, doi : 10.1002 / mmnz.19910670108 .
  2. a b Ulrich Joger , Daniela Guicking, Svetlana Kalyabina-Hauf, Peter Lenk, Zoltan T. Nagy, Michael Wink : Phylogeography, speciation and post-Pleistocene immigration of Central European reptiles. In: Martin Schlüpmann, Hans-Konrad Nettmann (eds.): Areas and distribution patterns. Genesis and Analysis. Festschrift for Prof. Dr. Reiner Feldmann (= journal for field herpetology. Supplement 10). Laurenti, Bielefeld 2006, ISBN 3-933066-29-8 , pp. 29-59.
  3. Klemens Fritz, Peter Sowig: Westliche Smaragdeidechse, Lacerta bilineata DAUDIN, 1802. In: Hubert Laufer, Klemens Fritz, Peter Sowig (eds.): Die Amphibien und Reptilien Baden-Württemberg. Ulmer, Stuttgart 2007, ISBN 978-3-8001-4385-6 , pp. 559-576.
  4. Lacerta viridis in The Reptile Database ; Retrieved January 9, 2011.

Web links

Commons : Eastern Green Lizard  - Album with pictures, videos and audio files
This version was added to the list of articles worth reading on June 5, 2006 .