Reptiles on the Dry Wall Circular Trail of Niedereggenen (Lörrach cty., extreme SW Germany)
GUNTRAM DEICHSEL, November 2014
Above the church of the village of Niedereggenen (part of the township of Schliengen) a very specific circular trail begins: it provides a walk through a dreamlike old wine growing area with many old limestone dry walls. The relatively small area bounded by the trail hosts a reptile fauna of surprisingly high diversity.
Abb. 1: The lower section of the trail with dry wall, abandoned vineyard, forest and the villages of Niedereggenen and Obereggenen in the background.
Common Wall Lizards (Podarcis muralis brongniardii) in good numbers can be seen on the walls in clear skies.
Abb. 2: Male Common Wall Lizard.
Abb. 3: Female Common Wall Lizard.
Abb. 4: Mating wall lizards. The male bites the flank of the female in order to generate support for pressing the cloacae together (photo: Dorothee Kling).
Sand Lizards (Lacerta agilis agilis) are rarely seen on the walls but they are seen more often than wall lizards at the forest borders and in sun-exposed places in the orchards and gardens.
Abb. 5: Juvenile Sand Lizard.
Abb. 6: Female Sand Lizard heavy with eggs (photo: Dorothee Kling).
Abb. 7: Male Sand Lizard.
Lizards play a role in human health – they are often interim hosts of ticks. Ticks that suck lizard blood become free of borreliosis. Thus lizards lower the risk for humans of becoming infected with borreliosis after a tick bite.
Abb. 8: Portrait of a male Sand Lizard infested with ticks.
Slow worms (Anguis fragilis fragilis) are not snakes, they are legless lizards. They live a hidden life in meadows and gardens and often seek shelter in wall joints at the bottom and under loose bricks on top of the walls. With a little bit of luck a specimen can be observed during basking, or with much luck preying on slugs, their chief diet.
Abb. 9: Basking Slow Worm.
Abb. 10: This Slow Worm is eating a Leopard Slug Limax maximus.
Smooth Snakes (Coronella austriaca) prefer to live in the system of wall joints. Usually they bask partially hidden in vegetation where they are frequently overlooked due to their unspectacular grey or brown coloration. At the easiest, one can discover their shed skins or sloughs.
Abb. 11: Slough of a Smooth Snake.
Abb. 12: This basking male Smooth Snake is typically half hidden. The glossy iridesence of the unkeeled scales is namesake for this snake (photo: Dorothee Kling).
Abb. 13: This female Smooth Snake is heavy with young, daring an open sun bath because she needs a good deal of warmth for the embryos to mature. Smooth Snakes are live bearing.
Abb. 14: If one gets too close to a Smooth Snake it takes a defensive posture as shown here against the photographer. Usually resting Smooth Snakes do not flee because they rely on their camouflage. However, they try to bite if they feel threatened when approached too closely. A strike leaves several blood drops which is as harmless as a rip by thorns. As a cautionary measure such injuries should be disinfected in order to avoid wound infections.
Western Grass Snakes (Natrix natrix helvetica) scavenge meadows and gardens for prey and like to use joints at the bottom of walls as shelters. In contrast to the bright yellow neck marks of the nominate form of the Grass Snake (Natrix natrix natrix), those of the western form are often pale or even missing. The black bars on the flanks are typical of the western sub-species.
Abb. 15: This Western Grass Snake is crossing the trail.
Abb. 16: Facing the photographer it displays an imposing mimicry behaviour: by spreading the movable jaws the head becomes triangular-shaped, mimicking the apparel of a venomous viper. However, the round pupils identify the snake as a harmless one. The bars on the flanks are mostly marked in the fore part of the body.
Both snake species found on of the trail, Smooth Snake and Grass Snake, are not venomous. In the rare event of an encounter, which is a case of good luck, there is no reason to panic! Stand still and observe the snake without disturbing it. It will never attack you, but as a rule it will flee from you. All our reptile species are strongly protected by law. Restoration and maintenance of the dry walls serve also the protection of the animal group of reptiles which get increasingly rare or locally extinct as our agricultural landscape becomes progressively more sterile.
I am indebted to Chris Davis and Gary Nafis for reviewing this English version languagewise and for their very helpful comments.
Author: Guntram Deichsel, Biberach an der Riss.
Wording and photos, if not otherwise indicated, © 2014 Guntram Deichsel.
