European Pond Turtle

(Emys orbicularis)


Facts

European Pond Turtle IUCN NEAR THREATENED (NT)

 

Facts about this animal

In general European pond turtles measure 13 up to 23 cm. Females tend to be larger than males, northern sub-species larger than those found in the south. Although the appearance varies over its large range, the European pond turtle is usually easily identifiable by the bright yellow or gold speckling on the dark (olive, brown or black) carapace and skin of many juveniles and adults.

 

However, some populations can be nearly entirely black with very few yellow markings at all (there are currently fourteen described regional subspecies, however there is much debate over their validity). The colour of the male's iris also varies from region to region, from red, brownish-yellow and yellow to pure white, while the eyes of females are generally yellow but occasionally also white. Although the European pond turtle will bask on the shore or on floating logs or emerging objects during the day, this shy species will quickly dive back into the water if disturbed.

Sexual maturity is usually reached at 5-12 years. The mating season begins immediately following hibernation at the end of March and ends around May, depending on the latitude. Male turtles “wake up” earlier and actively seek out female partners, using water-soluble pheromones secreted by receptive females as a positional cue. Both males and females prefer larger partners, as these promise a reproductive advantage. 3 to 16 eggs, usually 9 or 10, are laid in 1-3 separate ovipositions in May and June (but up to July) in small holes dug in the ground during the later hours of the day, in some cases miles away from the home range. The incubation period varies from around 57 to 90 days, and young may emerge in autumn or stay in the nest until the following spring, surviving brief frost periods of up to –6°C. In the northern parts of its range, a long hot summer is required for eggs to hatch, so this turtle may only successfully reproduce once in every four or five years. The average size of hatchlings is 26mm and the average weight is 5g.

 

The species hunts underwater for fish, amphibians, tadpoles, worms, molluscs, crustaceans and aquatic insects, as well as foraging for the occasional plant. The diverse climatic conditions of its extensive distribution mean that, in the northern parts of its range, this turtle is forced to hibernate for long periods during the cold winter months, while in warmer, more southerly areas, it often to the contrary aestivates to escape the summer's heat.

Did you know?
that already Aristoteles mentioned the European pond Turtle under the name “mus aquaticus“ (= water mouse). In the 1. century A.D. Plinius used for the first time the name „emys“ However Conrad Gessner gave it in 1617 the scientific denomination Testudo lutaria. This denomination can also be found with Linné (1758), who, in his “Systema naturae” by mistake also called the species Testudo orbicularis. This name was established in 1876 by W. T. Blanford as defintive denomination according to still valid rules of nomenclature. The species name „orbicularis“ („with little circles“) therefore origiates with Linnè and indicates the yellow spots on skin and plastron. In the 18. and 19. century the name Testudo europaea was used, going back to Schneider (1783). The zoological genus Emys, which contains the European pond turtle as single species, was described by Dumeril in 1806. Gray called the European pond turtle in 1831 Cistudo europaea („European turtle“). This name was – finally – replaced by Bibron in 1835 with Emys orbicularis. Until well into the 19 th century, the nominate form Emys orbicularis orbicularis was relatively common in Germany and Austria, but subsequent climatic and human-induced changes in their habitat, as well as their popularity as a meat substitute during the catholic fasting period, left these species threatened with extinction in these areas.The home range can be as big as 700m² - 5000² and 3m in depth; additional inland excursions of up to 4 km have been recorded. The European pond turtle belongs according to the groudbraking work of Claude Pieau (from 1974) to the reptiles with, von temperature-dependent sex determination (TSD). If the incubation temperature stays below 28°C only males are produced and with tepreratures above 29,5°C the hatchlings are predominantly females. Between 28°C and 29,5°C both sexes can develop Thus the so called pivotal temperature for temperature-dependent sex determination is in general indeed around 28.5°C. In German E.o. however, genetic predisposition or maternal influence appears to play an important or even predominant role.


 

Factsheet
Class REPTILIA
Order TESTUDINATA
Suborder CRYPTODIRA
Family EMYDIDAE
Name (Scientific) Emys orbicularis
Name (English) European Pond Turtle
Name (French) Cistude d’Europe
Name (German) Europäische Sumpfschildkröte
Name (Spanish) Galápago europeo
CITES Status Not listed
CMS Status Not listed

 

 

Photo Copyright by
George Chernilevsky

Distribution

 


Distribution
Range North Africa; Central Asia; Turkey; Southern, Central and Eastern Europe
Habitat Found in a wide variety of aqueous habitats, some of which may even dry up during the summer months, like rivers and streams, lakes and ponds, irrigation/drainage ditches, cattle trenches, and even the brackish waters of estuaries and coastal wetlands. However the ideal territories are characterised by large bodies of slow-moving fresh water with soft bottoms (mud or sand), lush vegetation and nearby sandy areas for nesting, although juveniles prefer shallow waters with depths of up to 50 cm. The water is left to bask or nest
Wild population The European pond turtle's wide distribution gives a deceptive impression of abundance, since its occurrence is often highly localized and populations in many parts of its range are in fact undergoing severe declines. Probably the greatest threat to this species comes from water pollution from agricultural, industrial and domestic/residential sources. Habitat destruction as a result of changing agricultural practices is also responsible for much of this decline. Particularly damaging have been the conversion of earthen drainage ditches to concrete ones as well as the the regular burning of vegetation The increasing exploitation of groundwater resources and urban expansion have also destroyed many areas where this turtle was once plentiful. The introduction of the exotic species, the red-eared slider (Trachemys scripta elegans), to a number of areas, probably from released pets, is also of particular concern as it competes for the same food resources and basking spaces as the European pond turtle. In addition the hatchlings and young animals have (and always had) a number of enemies like wild boar, badger, fox, crow,raven, magpie, heron and other birds, but also cat and dog. As soon as the hatchlings are in the water they may be taken by pikes and catfish. Aduld specimens have however no more enemies in the animal world. Illegal commercial collecting of the species from the wild for the pet trade has also occurred, although most specimens on the market probably now are captive bred. Indeed the European pond turtle is legally protected over much of its range and long-term conservation projects (including captive breeding and reintroduction programmes) have bee put into place. Encouragingly some of these reintroduction programmes have proved to be very successful, with high rates of survival and nesting behaviour following their release. This provides hope for the possibility of other reintroduction programmes in the future, where numbers in the wild should fall too low.

In the Zoo

European Pond Turtle

 

How this animal should be transported

For air transport, Container Note 43 of the IATA Live Animals Regulations should be followed.

 

Find this animal on ZooLex

 

Photo Copyright by
Wolfgang Simlinger

How this animal should be kept

Since this species is protected throughout its range, the collecting and keeping of specimens of wild origin is in general forbidden. Therefore only captive-bred specimens may be kept.

For the summer from April/May (when the water temperature has reached 15 °C) a fenced-in garden pond with a minimum of 18 m² that receives direct sunlight throughout the day is ideal. It should provide a variety of deep and shallow areas, with a platform (e.g. a log) for basking and a land area with a sandy slope for oviposition. The water temperature should be between 18 and 25 °C. The enclosure should be protected with wire mesh or a net against predators such as cats, rats, crows and birds of prey. The animals can be placed straight in the pond in spring provided that it contains shallow areas which will quickly heat up in the sunlight; otherwise the turtles should be kept temporarily in a spacious well-structured indoor vivarium with a basking ramp during a transition period (see below). In autumn they should remain outdoors until they are ready for hibernation to allow their metabolism to wind down optimally. In winter (i.e. from middle November to middle April) the pond turtle should hibernate at around 5°-6C, possibly in the refrigerator in water tanks with a water depth of app., 5 cm.
The vivarium for the transition period should measure at least 150cm x 60cm x 50cm for 2-3 adult specimens.In particular for adult females, a sandy area for oviposition must be available in order to avoid a potentially fatal dystocia (egg-binding). During the transition period, ambient water temperature is sufficient. The water tank should contain roots and aquatic plants as secure underwater hideouts and resting or sleeping places, some of which should be close to the water's surface. Natural aquatic plants generally do not survive the conditions found in turtle tanks. In addition, a floating log or large root that extends beyond the water should serve as a basking platform. An efficient but slow-flowing canister filter with the largest possible filter volume is needed as turtles are heavy water pollutants. Appropriate filter material consists of a combination of foam, pumice, lava and zeolite. Every 2-4 weeks, the water in the tank should be partially replaced with fresh water and excess waste should be removed.

When pond turtles are kept indoors permanently, they require not only adequate temperatures but also very bright illumination, both of which are necessary to prevent these diurnal poikilothermic reptiles from dropping into a prehibernation-like state with reduced metabolism. Warmth and lighting can be provided by metal halide lamps (e.g. Osram HQI or HCI) with colour temperatures around 5000 °K. Alternatively, incandescent mercury vapour bulbs such as PowerSun or Active UV Heat can be used in combination with fluorescent tubes of sufficient wattage and appropriate light colour (e.g. Osram Lumilux Daylight). The duration of the illumination should vary according to the natural daylight time of the season. In permanently dark surroundings, especially in basement rooms, dawn and dusk should be mimicked using a succession of lamps, and at night, a faint light should provide an orientation point (essentially an artificial ‘moon'). Additional UV-lighting is superfluous for turtles housed outdoors for most of the year and fed with a varied natural diet during the indoor transition periods. Those kept in an vivarium indoors year-round, however, require UV heat lamps, such as PowerSun 160W (all day) or OSRAM Vitalux/Radium Sanolux (about 10-15 min daily), in order to prevent metabolic bone disease and the resulting deformations of shell or skeleton. At the basking spots the temperature may reach 40 °C .For turtles kept permanently indoors the water temperature should be increased to 25°-27°C in summer, with the heating turned off at night. Like many other aquatic turtles, they are not overly sensitive to changes in temperature: The leap from a sunny dry spot back into the water can cause an abrupt temperature drop of over 10°C. The vivarium should remain uncovered, but protected from drafts. Three times per week they should be fed with appropriate food.