Water turtles
The European pond turtle Emys orbicularis orbicularis LINNAEUS, 1758
Emys orbicularis is still relatively common in the Mediterranean region. It is the only species of turtle that is native to Germany, Switzerland and Austria. However, these stocks are extremely rare. The northernmost occurrences are known in Lithuania. The European distribution area extends from the Iberian Peninsula over southern France, Italy, most of the Mediterranean islands, Poland, Hungary, Romania over the entire Balkans. It is also found in Turkey, parts of West Asia and parts of North Africa. A number of subspecies are described.
In their area of distribution, the pond turtle can be found in almost all suitable, standing or slowly flowing waters. Herbaceous waters with lush aquatic and bank vegetation and a muddy bottom are preferred.
In agricultural areas, the pond turtle can be found in almost every irrigation ditch, even in foul-smelling sewers and ditches. In the latter, surely only because it is the original habitat that has been polluted by human hands.
The animals can even be observed in brackish water.
Because most of these ditches and accumulations of water dry out completely in the hot summer months, the pond turtles dig themselves into the still wet mud in good time to survive the waterless period in a kind of summer rigidity in the mostly superficially drying mud. Only a few animals have the opportunity to migrate to nearby, constantly water-bearing rivers or lakes.
The pond turtles have an extremely shy way of life in their primary habitats and have a long flight distance. For this reason, turtles sunbathing on land are rarely seen. At the slightest disturbance, the animals run into the water, almost overturning, or simply let themselves fall from their sunny spot. Once in the water, they immediately swim to the bottom, bury themselves in the mud or hide in the vegetation. Often you only hear a splash at a distance of up to 20 meters and you don't know whether a frog or a turtle has fled into the water.
Sometimes the pond turtles can be seen swimming freely in the water. But here, too, the animals are very sensitive to falling shadows, movements or vibrations. However, motionless observers are not noticed by the turtles.
For sunbathing, the pond turtle likes to use tree trunks hanging in the water, all kinds of objects floating on the water and small clearings in the bank vegetation. The turtles also like to sit in close proximity to other conspecifics or even on top of each other in order to increase their vigilance towards predators. When sunbathing, the turtles like to take a slightly inclined position and at the same time stretch their head and limbs far out of the shell in order to absorb the solar radiation with as large a surface as possible.
In the main mating season in spring you can sometimes watch animals drifting in the water during the advertising ritual. The male sits on the back of the female and holds onto the edge of the tank with its claws. At the same time, the male, with his neck stretched out, constantly nods towards the head of the female. However, direct bites are rare. During the ritual and the subsequent mating, the pond turtles are so focused on themselves that they apparently no longer notice their surroundings and show no escape reaction.
From April onwards, the females dig nesting pits in the immediate vicinity of their waters and lay their eggs there. A second clutch takes place after about four weeks. Hatchlings and younger pond turtles lead a very hidden life in the mud and in the vegetation and are therefore rarely seen.
All representatives of the European pond turtles are omnivorous. The animals are very active and persistent hunters. They eat anything that can be hunted. From small crustaceans and freshwater prawns, which are abundant in some places, to snails, (unfortunately) also tadpoles, small frogs, amphibians, newts and their larvae.
The small goblin carrages (Gambusia affinis) found in almost every body of water are often hunted and eaten. The gambuses were introduced from the southern states of the USA at the beginning of the 19th century to control mosquitoes throughout the Mediterranean and can still be found in almost every water reservoir in the Mediterranean today
Pond turtles share the same enemies as their terrestrial relatives. Often, however, they can escape faster in the water and hide better.
The increasing drought causes some of the accumulations of water to fall permanently dry, thus robbing the pond turtles of their habitat.
In the cultivated areas, irrigation ditches and channels are increasingly being laid in pipes, thus depriving the animals of their habitat. In the vicinity of cities or areas used intensively for agriculture, streams and rivers with sewage, overfertilization or pesticides are already similar polluted that, despite the relatively high tolerance of the animals, no turtles can live here either.
Pond turtles spend the winter buried in the mud.
West Caspian brook turtle Mauremys rivulata VALENCIENNES, 1833
Moorish brook turtle Mauremys leprosa SCHWEIGGER, 1812
There are a number of German names for the water turtles, called Mauremys caspica, when I was a young boy. Even today, people still don't seem to agree on the Latin naming. But here, too, the name used or the classification into species or subspecies does not play a role in the description of the way of life.
The Mauremys are not found in the entire Mediterranean area like the Emys, but are absent in all of Italy, including the Italian islands, and on the Adriatic coast they only appear again in isolated cases in the extreme south of Croatia and then again from Montenegro. Otherwise the occurrence in the European Mediterranean area coincides with that of the European pond turtle. Mauremys often live mixed directly next to Emys, but generally prefer flowing waters and even larger rivers. There are two species in the European Mediterranean: Mauremys leprosa is native to the west of Italy and Mauremys rivulata to the east of Italy. The way of life of the two species does not differ.
The primary waters are wider brooks and slow-flowing rivers, where the animals stay under the often overhanging embankments and in the quieter peripheral zones in the vegetation. In the meantime, however, the river turtles can also be found in stagnant waters and even in smaller ponds as well as in ditches, often in very large numbers. If these waters dry out in summer, the river turtles, buried in the mud, also keep a summer dormancy. In primary habitats, Mauremys are also shy and have a great escape distance. However, the Mauremys are not quite as cautious as the Emys and reappear relatively quickly after an escape in order to carefully observe the area. Mauremys are also very tame in tourist areas and even leave the water when they see people to literally beg for food.
The river turtles can often be found in large groups while sunbathing. Preferably on overhanging, heavily overgrown banks on which real steps have been stepped into the ground. Trees and branches sticking out of the water, tufts of grass and all sorts of other places in the sun are also used.
While young animals mainly feed on animal food, older animals also graze on algae and aquatic plants very persistently. Otherwise, as with the Emys, everything that the living water offers in terms of food, falls on the water surface or is found in the form of carrion is eaten. In some of the smaller pools, the animals stand in the tadpoles of the innumerable water frogs. In contrast to Emys, who can only eat in water, I've seen Mauremys eat on land and even graze plants.
With the turtles, the advertising ritual begins with intensive head-to-head contact, with the male moving his head back and forth in front of the female's head. Finally, as the Emys do, the male sits down on the female's armor and clings to the edge. Here the female is repeatedly bitten in the neck after wild back and forth movements. For copulation, the male slides down backwards.
The eggs are buried in small egg pits near the bank from the beginning of May. Usually a second clutch follows.
Hatchlings and younger turtles live in large numbers in shallow marginal areas, often separated from the actual body of water, or in very shallow puddles in which the water is very warm.
The brook turtles also spend the winter buried in the mud of their waters. In southern Spain and southern Portugal, Mauremys leprosa is also active in winter due to the mild temperatures.
The red-eared slider turtle Trachemys scripta elegans WIED, 1839
The red-eared pinned turtle, which originally came from America and has been imported in huge quantities in the past decades, has meanwhile found an extensive distribution in nature in the Mediterranean region, together with other non-native turtles. Unlike in more northerly areas, these turtles can also reproduce successfully there, so that in many wetlands, ponds and streams in the Mediterranean area ear turtles of all sizes can be found alongside the native river and pond turtles. Unfortunately, they live there in competition with the pond turtles and have already displaced them in many places. As omnivores, Trachemys are not only food competitors, they also do not disdain the relatively small young of Emys and Mauremys. I know of a smaller lake in Greece where we were able to observe a larger population of Emys in the 1990s. When we visited this lake in May 2004, we only found red eared turtles there. In some places, signs have already been put up to educate the population.
In Spain, the red-eared tortoises have reproduced in an extensive ditch and irrigation system to such an extent that hundreds of tortoises have certainly found a new habitat there.
