Smooth snake
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Smooth snake ( Coronella austriaca ) |
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| Coronella austriaca | ||||||||||||
| Laurenti , 1768 |
The smooth snake ( Coronella austriaca ), also called smooth snake , is a very small and inconspicuous species of snake belonging to the family of snakes (Colubridae) , which occurs in large parts of Europe and western Asia . It is also widespread in Central Europe . This non-toxic snake is completely harmless to humans - however, it is not infrequently confused with the adder . Both species are protected in many countries and are neither pursued nor caught. The smooth snake was reptile of the year 2013 in Germany.
etymology
The name "smooth snake" goes back to the behavior that larger prey are entwined and suffocated before they are eaten. The term "smooth snake" is reminiscent of the smooth, unkeeled scales. The name "hazel snake" is used less often, it may have been inspired by the brown color of the back spots. There are also other regional or outdated trivial names, including "copper snake", "Austrian snake", "brown heart snake" and "spotted snake". The current scientific name Coronella austriaca was derived from the sometimes heart- or crown-shaped drawing on the back of the head ( Lat. Coronella = little crown) and the origin of the specimens first described by Laurenti (Lat. Austriaca = Austrian).
features
anatomy
Smooth snakes are delicate, slender snakes; they reach a body length of 60 to 75, occasionally 80 centimeters (in individual cases specimens with a total length of around 90 cm have been observed). A size difference between the sexes is not significant. The tail makes up 12 to 25 percent of the total length. It tapers evenly and ends pointed. The body weight of average animals is 50 to 80 grams, weights over 100 grams are rarely mentioned. Large pregnant females reach higher weights. The body is cylindrical (rounded in cross-section), with the front and rear sections having smaller diameters than the center. The transition from the narrower neck to the wider head is fluid. The top of the head is flattened, the sides and tip of the muzzle are rounded. The eyes are relatively small with a round pupil (an important distinguishing feature from the adder); the iris is brownish. A longitudinal furrow runs between the eye and the nostril. There are 12 to 16 teeth in the upper jaw, which increase in length towards the gullet, while the same number of lower jaw teeth are all similarly long.
With regard to the scaling of the head and body (compare: snake scaling ), the following properties are to be mentioned: There are seven upper lip shields ( supralabials ) and eight to nine lower lip shields ( sublabials ) on each side . The snout shield ( rostral ) is large and extends between the nostrils. In contrast to the Girondins smooth snake , it pushes itself in a wedge shape between the internalsals, which gives them a butterfly shape. The nostrils sit centrally in the nasals. The largest shields of the skull are the two elongated parietals. The body scales are smooth without a keel. Directly behind the head they are rather rounded and small, towards the tail they become elongated and pointed. On the tail they have a five- to hexagonal shape, on the sides of the body they are wider than on the back. In the middle of the body, the transverse rows consist of 19 scales each. Belly splints are between 150 and 190, pairs of tail shields between 40 and 70. The anal shield is usually divided.
Coloring and drawing
The basic color of the upper side is gray, gray-brown, brownish or reddish-brown. In males, brown to reddish tones dominate, while the females are often more gray. However, the coloration is not a completely clear distinguishing feature for the sexes (only the protruding hemipenes of the male can serve for this purpose). On the sides of the head there is a characteristic dark brown stripe that runs from the nostril over the eye to the corner of the mouth. Often it continues to the side of the neck, from where it changes into small individual spots. On the top of the head there is a heart-shaped or horseshoe-shaped dark spot (the "little crown"), which often continues in two longitudinal stripes on the back, only to finally dissolve into two (rarely four) rows of spots. Towards the tail, these spots become increasingly indistinct. Occasionally the spots can also merge into horizontal stripes. Despite all the variability of the dorsal speckle pattern, the smooth snake does not have a zigzag band like adders do. However, such an impression can arise through movements of the snake.
The belly side is never yellowish-white, as is the case with the grass snake, but different shades of brown and gray predominate here - often with lively dark speckles. The underside of the tail may occasionally be black. The underside of the head and the margin of the upper jaw are light and covered with fine blackish dots and lines. Young animals very often initially have a plain brick-red underside. They are also characterized by a darker, more contrasting markings on the back and a matt black top of the head.
distribution
The smooth snake is widespread in Europe and also reaches parts of western Asia . It occurs from the north of the Iberian Peninsula over the south of England , western , central and eastern Europe eastwards to far in Russia and on the northwestern edge of Kazakhstan . In the south, in addition to northern Portugal and Spain , Italy (including Sicily ), the entire Balkan Peninsula , the northern part of Anatolia , the Caucasus and the northwestern tip of Iran are settled. The northernmost occurrences are located next to the European part of Russia in southern Norway , southern and central Sweden (including the islands of Öland and Gotland ) and on the Finnish Åland islands. The Scandinavian range is now isolated from the rest of the area after the species became extinct in Denmark. The vertical distribution ranges from sea level to 2200 meters in the Bulgarian Rila Mountains and 3000 meters in the Caucasus .
In Switzerland , in Austria and Germany , the smooth snake is also widely available, but none of coverage. In Switzerland, the species is considered to be the snake with the largest distribution area, although the density of sites varies greatly locally and there have also been significant populations in recent decades (see section “Endangerment and Protection”). The highest evidence in the Central Alps is at 2100 meters. In the high mountains only the southern flanks of the mountains are settled; in the Central Plateau it is mainly the canyons , valley floors and slopes on the edge of the Molasse Mountains and the hilly areas. The situation is probably similar for Austria; here heights up to a maximum of 1800 meters are available.
In Germany, the main distribution of the smooth snake is thermally favored upland regions Southwest , South and South-East Germany (often simultaneously wine regions ), while the area to the north more and more into disjoint dissolves subdivisions and remove the population strengths. In large areas of Schleswig-Holstein and Mecklenburg-Western Pomerania, the species is completely absent (exceptions are isolated outposts on the Baltic coast between Rostock and Darß , on Hiddensee and Rügen and in the Ueckermünder Heide ). Otherwise in are North German lowland especially the heath and sand areas - Brandenburg , parts of the mainly medium Lower Saxony Geest - and Moor - lowlands and the Westphalian Bight populated. A more or less closed area can be found in the low mountain ranges of western and southwestern Germany . In the Rhein-Main area is the most common snake. Furthermore, there is the kind of regular including in the Franconian Jura and adjacent limestone areas, in the Thuringian basin , in the Dresden Elbe Valley and in the Oberlausitz ago. In the Black Forest heights are up to 1110 m above sea level. NN inhabited ( Belchen ), in the Bavarian Forest up to 850 m (otherwise in the low mountain ranges of Germany it is rarely more than 650 m). In the Berchtesgaden Alps , high-montane locations of 1300 meters are also reached. In the foothills of the Alps , it is mainly the large river valleys that are found, while otherwise there are larger gaps in distribution.
Subspecies
There are currently three subspecies of smooth snakes. In addition to the nominate form , which takes up most of the area, these are Coronella austriaca acutirostris in northern Portugal and Spain and Coronella austriaca fitzeringi in southern Italy and Sicily. The subspecies status of the latter is, however, doubted by some authors.
Habitats
The smooth snake is a xerothermophilic (drought and heat-loving) animal species that populates a wide range of biotope types depending on the region . While in northern Germany, the Netherlands and southern England, for example, sandy heaths, poor grasslands and dry upland moor and forest edges are important habitats, in the Central European Central Uplands it is mainly hillside locations with poor and dry grass, scree slopes, dry stone walls and abandoned vineyards (vineyards). In higher low mountain ranges, in eastern Bavaria or also in southern Sweden, sunny forest edges in the vicinity of extensively cultivated meadows, bushes, hedges, woodlands, rock heaths, semi-bushy grasslands and embankments form the natural habitat of the smooth snake. In the Alpine region, a large number of open to semi-open habitats are populated in locations with favorable warmth. In addition, there are special anthropogenic locations such as railway embankments and quarries everywhere. Smooth snakes are also found occasionally on the near-natural structured settlement edges of villages and towns.
What all habitats have in common is a mosaic-like, small-scale alternation of open, low-growth and sometimes wood-dominated locations and a high density of small structures and shelter. In the same habitat there are usually many lizards (especially sand lizards , regionally also forest lizards or wall lizards ) and slow worms . Occasionally the adder occurs syntopically .
Way of life
In Central Europe, smooth snakes can be observed regularly between April and October, occasionally earlier and later. They spend the winter rigor in small mammal burrows, cavities between stones and similar frost-proof locations. In May at the latest, an initial peak of activity can usually be recorded; Most matings and the first molt occur during this phase . Depending on the external temperatures, the snakes are active in the morning or morning and in the evening (summer, heat) or at noon (spring, autumn) in order to expose themselves to solar radiation for the purpose of thermoregulation . At night, in great heat or in cool, rainy weather, they retreat to their resting places. An individual can have a territory of several hectares within which it undertakes major seasonal “migrations” (change of location). On the other hand, the species is characterized as being extremely local.
Smooth snakes often remain motionless and trust that they will allow the inconspicuous coloration and the speckled pattern to blend in with their surroundings. If they feel cornered and threatened with no means of escape, they curl up like a plate and lift the front part of the body in an S-shape. They rarely make hissing sounds. If the distress persists, they also try to bite the attacker very often. In this case, the snake does not immediately let go, but sometimes makes chewing movements. In humans, however, the small teeth leave no more than a few scratches. Occasionally the animals move forward at lightning speed without opening their mouths - so there is no real bite with such pseudo attacks. Finally, as with all snakes, a sharp-smelling secretion can be secreted from the anal glands.
Their predators include polecats , stone marten , hedgehogs and various birds of prey , and corvids also hunt the young . They themselves primarily prey on lizards and their eggs or young animals as well as blindworms , as well as young snakes (including those of their own species, especially with high population densities), nest-young and adult shrews , voles and long-tailed mice . Garlic toads , large insects, nesting birds and bird eggs as well as earthworms can also be irregularly part of the food spectrum. Larger prey is visually located, tracked, jawed and strangled before devouring. To do this, the snake wraps its body tightly around the victim.
Reproduction and Individual Development
At the mating season in late spring, the males behave very aggressively and eagerly to bite towards other conspecifics. Real wrestling matches with other males can result in serious injuries. The female is also sometimes bitten in the neck or throat during mating and embraced. Before that there is a ritualized foreplay with tongues, nods and crawling of the female. The duration of the copula ranges from 20 minutes to several hours.
The gestation period lasts four to five months on average, so that in Central Europe the young are usually born between mid-August and the end of September. Unlike the grass snake, the smooth snake does not lay eggs, but is viviparous. More precisely, the young animals are still in a thin egg shell at birth, which they then immediately pierce through body convolutions (so-called ovoviviparia ). Each female gives birth to between three and 15 young, depending on the size of the mother. Most females take a breeding break in the following year, but sometimes there are annual or three-year intervals.
The young are between 12 and 21 centimeters long at birth. A short time later the first molt occurs and they go looking for food. Within the second year of life, they roughly double their initial length to reach a size of 30 to 40 cm in the third year. Sexual maturity occurs in the third or fourth year of life with a length of 40 to 50 cm. After that, body growth continues to slow down. About two to six moults occur in adults within a year . The maximum individual age for smooth snakes is assumed to be around 20 years.
Hazard and protection
The smooth snake is strictly protected in many countries and may not be caught or even killed. Nevertheless, it still happens that this animal, which is absolutely harmless to humans, is slain - as a supposedly dangerous poisonous snake or out of a subliminal hatred of snakes. Many reptiles, even the slow worm , are considered "threatening" out of ignorance, but the smooth snake can be confused with the adder (which is also under protection and may no longer be pursued). Sharp declines in the smooth snake population have been observed in various regions over the past few decades.
The main threat comes from habitat destruction. Due to the intensive use of the Central European cultural landscape and a misunderstood sense of order, many biotopes that are important for smooth snakes and other reptiles have been eliminated or devalued. Almost everywhere there was and there is the trend to convert varied, "untidy" landscapes into large, structurally poor, often over-fertilized agricultural areas. In the process, hedges, herbaceous vegetation, rocky peaks, piles of stone piles, dry stone walls and other small structures were removed, and marginal strips and transitional biotopes ( ecotones ) straightened. Remaining biotope islands and strips are often too small and isolated from one another, are either not cared for at all (which leads to an unfavorable amount of bushes) or too intensively (for example through improper mowing, whereby many small animals are destroyed). In addition, there are other factors such as increasing land consumption through settlement and road construction, the backfilling of quarries, the use of pesticides , locally also frequent disturbances of the snakes due to leisure activities, free-roaming dogs or stray cats.
Legal protection status (selection)
- Habitats Directive : Annex IV (species to be strictly protected)
- Federal Nature Conservation Act (BNatSchG): strictly protected
National Red List classifications (selection)
- Red List Federal Republic of Germany: 3 - endangered
- Red List of Austria: VU (endangered)
- Switzerland's red list: VU (endangered)
swell
The main source of the article as amended on August 31, 2008 is the following literature :
- Rainer Günther & Wolfgang Völkl: Schlingnatter - Coronella austriaca Laurenti, 1768. P. 631–647 in: R. Günther (Ed.): Die Amphibien und Reptilien Deutschlands. Gustav Fischer, Jena 1996, ISBN 3-437-35016-1 .
- Wolfgang Völkl & Daniel Käsewieter: The smooth snake - a secret hunter. Laurenti-Verlag, Bielefeld 2003, 151 pp., ISBN 978-3-933066-15-2 .
- Michael Waitzmann & Peter Zimmermann: Schlingnatter, Coronella austriaca Laurenti, 1768. P. 633–650 in: Laufer / Fritz / Sowig (Eds.): The amphibians and reptiles of Baden-Württemberg. Ulmer, Stuttgart 2007, ISBN 978-3-8001-4385-6 .
In addition, the following individual certificates are listed:
- ↑ Daniel Käsewieter: Ecological studies on the smooth snake (Coronella austriaca Laurenti 1768). 2002.
- ↑ Ulrich Hofer: On the situation of smooth snakes (Coronella austriaca, Laurenti 1768) in Switzerland. Pp. 91-104 in: Michael Gruschwitz et al. (Ed.): Distribution, ecology and protection of snakes in Germany and neighboring areas. Mertensiella 3, Bonn 1993, ISBN 3-9801929-2-X
- ↑ Online overview at www.herpetofauna.at
- ^ Coronella austriaca in The Reptile Database ; Retrieved January 9, 2011.
- ↑ Schlingnatter at www.wisia.de
- ↑ Federal Agency for Nature Conservation (ed.): Red list of endangered animals, plants and fungi in Germany 1: Vertebrates. Landwirtschaftsverlag, Münster 2009, ISBN 978-3-7843-5033-2
- ↑ Online overview at www.amphibienschutz.de
Web links
- Coronella austriaca in The Reptile Database
- Photos of the smooth snake at www.herp.it
- The smooth snake in Austria on www.herpetofauna.at: Species description, distribution and pictures
- Smooth Snake ( Memento from October 26, 2013 in the Internet Archive )
- Information and photos at reptilien-brauchen-freunde.de
- Distribution in Europe ( Memento of April 13, 2012 in the Internet Archive ) (351 kB)
- The smooth snake. Reptile of the year 2013
Forest Lizard (2006) | Common Garlic Toad (2007) | European tree frog (2008) | Dice Snake (2009) | Pond newt (2010) | Wall Lizard (2011) | Common Toad (2012) | Smooth Snake (2013) | Yellow-bellied toad (2014) | European pond turtle (2015) | Fire Salamander (2016) | Slow Worm (2017) | Common Frog (2018) | Mountain Newt (2019)
