European Pond Turtle Emys Orbicularis Research Articles

Nesting habitat characteristics and predation patterns in the European pond turtle Emys orbicularis (L., 1758): Implications for management and conservation measures

Integrating knowledge regarding habitat characteristics and animal behaviour into conservation programs has the potential to impact the results of management and conservation efforts. This study aimed to explore the relationship between spatial and environmental data on the nesting activity of the European pond turtle, Emys orbicularis. Additionally, it sought to analyse the abundance, activity pattern, and behaviour of potential nest predators of E. orbicularis. Natural predated nests of the European pond turtle were utilized to characterise nesting habitat features, while artificial nests and camera traps were deployed to identify potential predators and their behaviour. Artificial nests and camera traps were established in areas with evidence of track detection or historical observations indicating past instances of nest predation. The nest site distribution of the European pond turtle showed a positive relationship with north-south oriented canals, the presence of vegetative components on embankments (shrubs, grass, emergent vegetation), finer-grained soil components (silt and clay), and soil moisture. Camera trapping of artificial nests revealed mammals (Meles meles and Vulpes vulpes) and a bird (Pica pica) as predators engaging in digging and destroying behaviour. P. pica detection was notably higher in mowed vegetation areas. Results indicate that natural nest distribution and predation on artificial nests may be influenced by their distribution concerning human-controlled vegetation and foraging activities of common nest predators. Protecting nesting sites in predator-frequented habitats, combined with landscape management targeting vegetation control along embankments, could mitigate nest predation and enhance hatchling recruitment.

Direct and indirect estimates of dispersal support strong juvenile philopatry and male‐biased dispersal in a freshwater turtle species (Emys orbicularis)

Abstract Dispersal has major impacts on population dynamics, population genetics and evolution, and also is critical for population management and conservation. Dispersal is frequently sex‐ and age‐specific, but current knowledge is strongly taxonomically biased toward birds and mammals. Here, we provide estimates of dispersal in a threatened freshwater turtle species, the European pond turtle Emys orbicularis. Based on 15 years of capture‐mark‐recapture (CMR) monitoring and DNA samples from 194 individuals, we quantified both demographic and genetic dispersal between three sites separated by 1.5–3.5 km. We also investigated the effect of age and sex on dispersal. Direct (CMR) and indirect (genetic) approaches provided consistent results, showing that the studied sites are connected with a flow of about one to three dozen migrants per generation. Dispersal was both age‐ and sex‐biased in this species, with frequent dispersal of adult males and a strong philopatry of juveniles (of both sexes) and adult females. The network of canals and marshes allow effective dispersal to occur among the three study sites despite the relatively large distance separating them (≤3.5 km). The strong philopatry of juveniles contrasts with the frequently higher dispersal rate in young birds and mammals and shows the relevance of investigating dispersal in various taxonomic groups. Our results provide useful information for the conservation of European pond turtle populations.

Molecular Phylogenies of Leeches and Haemoparasites Infecting Freshwater Turtles in Aquatic Ecosystems of Northern Africa Suggest Phylogenetic Congruence between Placobdella costata Sensu Lato and Haemogregarina stepanowi Sensu Lato.

Haemogregarines are blood parasites with a life-cycle involving a vertebrate as the intermediate host and an invertebrate as the definitive host and vector. Extensive phylogenetic investigations based on 18S-rRNA gene sequences have shown that Haemogregarina stepanowi (Apicomplexa: Haemogregarinidae) is able to infest a large diversity of freshwater turtle species, including the European pond turtle Emys orbicularis, the Sicilian pond turtle Emys trinacris, the Caspian turtle Mauremys caspica, the Mediterranean pond turtle Mauremys leprosa, and the Western Caspian turtle Mauremys rivulata, among others. From the same molecular markers, H. stepanowi is further considered to be a complex of cryptic species predisposed to infect the same host species. While Placobdella costata is known to be the unique vector of H. stepanowi, it is only recently that independent lineages within P. costata have been illustrated-suggesting the presence of at least five unique leech species across Western Europe. The aims of our study were therefore to investigate from mitochondrial markers (COI) the genetic diversity within haemogregarines and leeches infecting freshwater turtles of the Maghreb, in order to identify processes of parasite speciation. We showed that H. stepanowi consists of at least five cryptic species in the Maghreb, while two Placobella species were identified in the same area. Although an Eastern-Western speciation pattern was apparent for both leeches and haemogregarines, we cannot make definitive conclusions regarding co-speciation patterns between parasites and vectors. However, we cannot reject the hypothesis of a very strict host-parasite specificity within leeches.

Molecular Screening of Haemogregarine Hemoparasites (Apicomplexa: Adeleorina: Haemogregarinidae) in Populations of Native and Introduced Pond Turtles in Eastern Europe.

Haemogregarines (Apicomplexa: Adeleorina) are the most common and widespread reptilian blood parasites. Haemogregarina stepanowi was the first haemogregarine described from a reptile, the European pond turtle Emys orbicularis, and initial assessments indicated it was widespread across different pond turtle host species across much of Europe, the Middle East and North Africa. However, recent molecular assessments have indicated the presence of multiple genetically distinct forms in North Africa and the Iberian Peninsula, and extensive mixed infections which may be associated with a negative impact on the hosts. Here, we screened two native species, E. orbicularis and Mauremys rivulata, and the introduced Trachemys scripta from Serbia and North Macedonia for haemogregarines by amplifying and sequencing part of the 18S rRNA gene of these parasites, and used a standard DNA barcoding approach to identify leeches, the final host, attached to pond turtles. Our results again demonstrate the occurrence of considerable diversity of parasites in the analysed pond turtle species, and that T. scripta are likely infected by local haemogregarine parasites, and not those that are found in its native range. Leeches were identified as Placobdella costata, part of a lineage from Northern Europe. Mixed infections within pond turtles were again common. Current haemogregarine taxonomy does not reflect the genetic diversity identified, and a full taxonomic reassessment is needed.

Blood parasite diversity (Apicomplexa: Haemogregarinidae) within the western populations of the European pond turtle Emys orbicularis.

Molecular tools have revolutionized assessments of blood parasites in freshwater turtles. In the Iberian Peninsula and North Africa, two native species of terrapins occur, Emys orbicularis (Linnaeus) and Mauremys leprosa (Schweigger). Both have been identified as hosts for the blood parasite Haemogregarina stepanowi Danilewsky, 1885, which has also been found in related species. However, recent assessments of M. leprosa have identified several distinct genetic lineages of these parasites in this host, while only three haemogregarine lineages were identified in E. orbicularis in Tunisia. Here, we screened 215 individuals of E. orbicularis from the Iberian Peninsula, Menorca Island and Morocco for haemogregarine parasites using partial 18S rRNA gene sequences to estimate relationships. Three unrelated lineages of parasites were detected, one presumed H. stepanowi and two lineages previously known from M. leprosa. A considerable undescribed diversity of parasites exists within these vertebrate host species, while mixed infection and host-sharing is also widespread. Considering that E. orbicularis is near threatened in this region, it is of great importance to identify the parasites infecting it, and to further assess the potential deleterious impact of these diverse parasites on their hosts.

An unexpected recapture of European pond turtle Emys orbicularis (Linnaeus, 1758) in the Barcs Juniper woodland (Hungary)

Little is known about the lifespan of free-living freshwater turtles in Hungary, because no long term monitoring has been conducted with such purpose. We captured a European pond turtle with markings on its carapace, at the dam of the lakes along the Rigóc stream in the Barcs Juniper woodland area on June 9, 2022. This female had been marked 16 years earlier, on July 17, 2006 in the framework of a genetic research project. At the time of marking it was 10 years old based on its growth rings, body mass was 630 g and carapace length was 151.6 mm. This individual was recaptured only 75 meters away from the place where it had been marked, thus it has been living in the same place for at least 26 years.

Fine scale behaviour and time-budget in the cryptic ectotherm European pond turtle Emys orbicularis.

For ectotherms, behaviour and associated energetic costs are directly related to thermal conditions. In the present context of global change, estimating time-budget for these species is relevant to assess and predict their capacity to adapt to near future. We tested the hypothesis that in ectotherms where reproduction is highly energy consuming, energy expenditure should vary throughout the breeding season with a maximum around nesting events. To test this hypothesis, we assessed the fine-scale behaviour, time-budget and estimated energetic costs in eight adult female European pond turtles Emys orbicularis equipped with data-loggers recording ambient temperature, pressure, light and the animals’ 3-axis acceleration. Deployments occurred over four months throughout the nesting season 2017 in semi-natural captive conditions in Alsace, France. All study turtles showed a clear daily pattern over the 24h cycle, with four distinct phases (referred to as Night, Morning, Midday and Evening), associated with different behaviours and activity levels. Before oviposition, turtles were mostly active during Morning, and activity was positively driven by ambient temperature. Activity levels doubled during the nesting period, mostly due to the increased activity in the Evening, when nesting events occurred. Throughout the active season, basking occurrence at Midday was related to air temperature but cloud coverage was an even more important factor. Our results are a first step in predicting the seasonal time and energy budgets of the European pond turtle, and demonstrate the usefulness of animal-borne accelerometers to study free living freshwater turtles over extended periods of time.

Distribution range and population viability of Emys orbicularis in Slovakia: a review with conservation implications

The European pond turtle (Emys orbicularis) is the only native freshwater turtle species in Slovakia. Due to watercourse regulations in the middle of the 20th century, its range became fragmented and, currently, there are only two isolated populations. From a total of 1,236 historical records in Slovakia, most observations (782 records) came from the area of the Tajba National Nature Reserve (NNR). Three of the population viability analysis models (‘baseline’, ‘catastrophe’, ‘nest protection during a catastrophe’) indicated the extinction of the population in Tajba, with the highest probability of extinction occurring during a catastrophic event (probability of extinction 1.00). We also evaluated information about the activity patterns of seven radio-tracked individuals and about the number of destroyed nests from the area. During the period 2017–2021, we recorded only two turtles leaving the aquatic habitat of Tajba. An alarming fact is the massive number of destroyed nests found in the area during the study period (Tajba 524; Poľany 56). Our results indicate that the population in the Tajba NNR require immediate application of management steps to ensure its long-term survival.

Reptile occurrences data in the Volga River basin (Russia).

BackgroundThe Volga basin is one of the most industrially-developed regions of Russia with a high degree of anthropogenic impact on natural ecosystems. Human influence negatively affects the species diversity and number of animals, including reptiles. There are no endemic species in the reptile fauna of the Volga basin. The herpetofauna of the region makes up 25% of the reptile fauna of Russia (Dunaev and Orlova 2017). We began to study the fauna of reptiles and their distribution in the Volga basin in 1988. Although we registered 20 reptile species in the Volga basin to date, apparently this is not a complete list of species in the region (Bakiev et al. 2004, Bakiev et al. 2009a, Bakiev et al. 2015, Kirillov et al. 2020). The distribution of reptiles in this region is not fully understood.New informationOur dataset contains information on reptile occurrences in the Volga River basin. The dataset is based on original research by the staff of the Laboratory of Herpetology and Toxinology and Laboratory of Population Ecology of the Institute of Ecology of the Volga River basin of the Russian Academy of Sciences and Joint Directorate of the Mordovia State Nature Reserve and National Park “Smolny”. A total of 5,086 occurrences of 20 species are published for the first time with georeferencing. Many of these reptiles are listed in regional Red Data Lists. The European Pond Turtle Emys orbicularis (Linnaeus, 1758) is included in the IUCN Red List with the category “Near Threatened”.

GIS-modeling of the Range Shifts of the Sub-fossil and Extant European Pond Turtle (Emys orbicularis) in Eastern Europe in Holocene

The study of the dynamics of the European pond turtle’s Emys orbicularis range and distribution as an indicator of climate change in the past, present, and future is most relevant in connection with the protected status of this species in Europe. Based on our original finds, 25 archaeological sites yielding 1623 remains of 1504 individuals of subfossil pond turtles, current marginal distribution in Latvia, Ukraine, Russia, and literature data, we analyzed 437 records of Holocene turtles and 2847 current records of pond turtles. We identified areas that could serve as refugia for E. orbicularis, as a result of GIS modeling, while using 19 bioclimatic variables from the Worldclim and PaleoClim data bases. The data obtained confirm current hypotheses regarding the origin of more than 10 mtDNA lineages of E. orbicularis and the existence of multiple glacial refugia, and considerable Holocene home range dynamics.

First data on the population of the European pond turtle Emys orbicularis at Lake Tonga, El Kala National Park, Algeria

AbstractThe North African distribution of

Demonstrating the value and importance of combining DNA barcodes and discriminant morphological characters for polystome taxonomy (Platyhelminthes, Monogenea)

Polystomes are monogenean parasites that infest mainly semi aquatic vertebrates, such as amphibians and chelonians. Owing to the lack of discriminative morphological characters and because polystomes are considered to be strictly host- and site-specific, host identity is often used as an additional character for parasite identification. Recent genetic studies, however, showed that polystomes infecting freshwater turtles in outdoor turtle enclosures and natural environments, were not strictly host-specific. Therefore, we proposed a new procedure for turtle polystome taxonomy based on the combination of Cytochrome c Oxydase I sequences and two discriminant morphological characters, namely the number of genital spines and the testis shape. We tested the validity of this procedure with Polystomoides oris, which was collected from the pharyngeal cavity of the American painted turtle Chrysemys picta and two undescribed species, both collected from the pharyngeal cavity of the American slider Trachemys scripta and two other European turtles, namely the European pond turtle Emys orbicularis and the Mediterranean turtle Mauremys leprosa. A Principal Component Analysis based on both morphological characters allowed the separation of all specimens in three morphological groups, which matched well with the molecular data. As a result, we describe two new polystome species, i.e., Polystomoides soredensis n. sp. and Polystomoides scriptanus n. sp.

Introduction and invasion of the red-eared slider and its parasites in freshwater ecosystems of Southern Europe: risk assessment for the European pond turtle in wild environments

The North American red-eared slider Trachemys scripta elegans, which is nowadays considered among the world’s worst invasive species, could constitute a real threat to native freshwater turtles. Because this species shares the same habitats of the European pond turtle Emys orbicularis since its introduction in the European wetlands, we surveyed populations of both alien and indigenous species in France and Spain in order to determine the diversity of platyhelminth parasites (Monogenea, Polystomatidae) in natural environments and to evaluate the levels of risks associated with parasitism. DNA barcoding procedure based on partial cytochrome c oxydase I sequences revealed ten monogenean parasite species within E. orbicularis populations and/or captive animals among which at least eight could be considered as introduced parasites from American freshwater turtles. Results indicated that host switching could have occurred either in natural environments or in captivity, when indigenous turtles were kept with exotic species, demonstrating that captive turtles could act as reservoirs of parasites. The presence of non-native parasite species within wild populations of E. orbicularis in the European freshwater ecosystems also highlighted the risks that these parasites may pose on the survival of natural turtle’s populations and on the dynamics of native parasites.

New data on distribution of the European pond turtle Emys orbicularis (Linnaeus, 1758) in the Podravje region (NE Slovenia)

Ten new observations of the European pond turtle Emys orbicularis (Linnaeus, 1758) in the Podravje region are presented. One observation is fairly old, while the others have been made in the last six years. Most of the data are just random observations and do not give a complete overview of the species distribution in the Podravje region. New data suggest that the European pond turtle is more abundant in the Drava River basin than previously known. Distribution and population size of the species in the Drava River basin still remain to be investigated in detail and not only at the Natura 2000 Drava site, especially in the areas of potential habitats prior to planning any new activities.

The good, the bad and the ugly: Emys trinacris, Placobdella costata and Haemogregarina stepanowi in Sicily (Testudines, Annelida and Apicomplexa).

Endemic Sicilian pond turtles Emys trinacris Fritz, Fattizzo, Guicking, Tripepi, Pennisi, Lenk, Joger et Wink were examined for the presence of haemogregarine parasites. The presence of haemogregarines, occurring mainly in the microgametocyte stage (13.2 ± 0.12 μm in length and 6.4 ± 0.52 μm in width), was observed in approximately 9% of the sampled E. trinacris. Based on the observed morphology and on the sequencing of nuclear 18S rDNA, we identified the parasite as Haemogregarina stepanowi Danilewsky, 1885. Morphometric study of uninfected and infected red blood cells has shown that H. stepanowi induces different changes in erythrocyte shape depending on the infective stage. The differential count of leukocytes in specimens infected with H. stepanowi showed no significant difference compared with healthy specimens. However, considering the health problems which might be induced by H. stepanowi in the closely related European pond turtle Emys orbicularis (Linneaus), monitoring of the health status of the infected Sicilian populations of E. trinacris is desirable. The restricted distribution of populations of Emys infected with haemogregarines in Sicily is quite puzzling and the possible human-mediated introduction of the parasite in Sicily is briefly discussed.

Challenges of monitoring reintroduction outcomes: Insights from the conservation breeding program of an endangered turtle in Italy

Captive breeding and reintroduction programs remain a powerful but divisive tool for management of threatened species, with a proven potential to avoid extinction, but low long-term success rates and high resource requirements. Monitoring the results of reintroductions is critical to be able to assess short- and long-term success, adjusting management decisions as new information becomes available. In this study, we assessed the first 15years of the captive breeding and restocking program for the European pond turtle Emys orbicularis in Liguria, northern Italy. We estimated survival of released turtles by modelling mark-recapture monitoring data. We then used those estimates to update our prior expectations about long-term outcomes, and to adjust management decisions about the age of individuals to release. Modelling results suggest released turtles had sufficiently high survival, matching prior expectations, such that local extinction has been averted in the short-term. Survival was similar among candidate age classes for releases, suggesting the release of younger individuals can provide positive outcomes while reducing management costs. On the other hand, survival varied among sites, indicating the need for ongoing in-situ habitat management to ensure long-term persistence. Moreover, the late onset of sexual maturity in the species means reproduction of released animals cannot yet be determined with certainty. Captive breeding and reintroduction programs normally require long-term efforts; therefore, focused monitoring that is clearly linked to decision-making is necessary to continually refine and adjust management strategies.

First record of the European pond turtle Emys orbicularis (Linnaeus, 1758) near Kočevje, SE Slovenia

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Attributes of basking sites of the European pond turtle (Emys orbicularis) in central Italy

Attributes of basking sites are important elements to study in management plans of threatened freshwater turtles. Here, we analyzed the basking-site characteristics of European pond turtle (Emys orbicularis) populations in a Mediterranean territory of central Italy (Tolfa Mountains, Latium). We used logistic regression and Principal Components Analysis to characterize 29 presence sites versus 61 random sites, through 16 descriptive variables recorded within a 5 m radius from the sighting/target spot. Our analyses revealed that some variables (i.e. water turbidity, presence of small coves, submerged vegetation, and emergent tree-trunks) were those that influenced most strongly the presence of turtles on potential basking sites. Maintenance of deadwood in water and preservation of submerged aquatic vegetation should be included in the management planning for this turtle species in central Italy.

Updated distribution of the European pond turtle Emys orbicularis (Linnaeus, 1758) and its conservation issues in Serbia

Although the European pond turtle (Emys orbicularis) has been included in studies for several decades, the information about its distribution and the state of populations in Serbia is still incomplete. The data collected from the available literature sources, and those based on the authors? own field investigations, indicate that E. orbicularis occupies a large part of the territory of the Republic of Serbia, preferring aquatic biotopes at lower altitudes. We compiled a list of 287 localities where the presence of the pond turtle has been recorded. Of those, 14% (40 localities) were known only from literature sources, localities added during our field investigations represent 82% (235 sites), 4% (12 localities) confirming literature data. We also gathered information on the main negative threats to the endurance of the pond turtle in Serbia. These are habitat pollution, degradation and destruction, and the spread of allochthonous invasive turtle species. Some protective and conservation measures are suggested in the conclusion.

Badger (Meles meles) predation on European pond turtle (Emys orbicularis) during the Eemian interglacial (MIS 5e)

Microstratigraphically classified fossil finds of Emys orbicularis from the open-cast lignite mine of Janschwalde and other sites of the Niederlausitz region (Brandenburg, E Germany) provide evidence for the occurrence of pond turtles during the last interglacial (Eemian, MIS 5e) for at least 4,600–5,200 years. Bite marks on the turtles’ upper and lower shells indicate predation by European badger (Meles meles). As part of a sophisticated killing technique, the predators smashed the nuchal area of the upper shell and the head of the turtles retracted underneath. The subsequent consumption of the soft body was initiated by opening the rear of the lower shell. The reconstructed preying behaviour would have only been possible in turtles up to a certain size and thus required the regular presence of small-bodied Emys individuals. Optimal prey specimens were of about 110 mm in shell length. Turtles with shells exceeding 135 mm and with some doming of the carapace were at lower risk, as a successful execution of the killing bite would not have been possible in these cases. The available Eemian record suggests that predation on European pond turtles was part of the badgers’ subsistence strategy for a period of at least 3,500–4,100 years. Although the demonstrated predator-prey relationship required narrowly defined environmental conditions, it occurred over a substantial portion of the last interglacial, a period of time characterised by temperate conditions and a certain climatic stability.