On a reproductive population of Trachemys scripta (Schoepff, 1792) at Kaiafa Lake in Western Peloponnese, Greece

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1 Societat Catalana d Herpetologia Butll. Soc. Catalana Herpetologia 26: Agost del 2018 ISSN Disponible en On a reproductive population of Trachemys scripta (Schoepff, 1792) at Kaiafa Lake in Western Peloponnese, Greece Elias TZORAS 1, Giorgos CHIRAS 1,2, Albert LOZANO 3, Joan MALUQUER-MARGALEF 3 1: ECOLOGICAL MOVEMENT OF PATRAS. Sachtouri 64, GR Patra, Greece. 2: ARCHELON, The Sea Turtle Protection Society of Greece. Solomou 57, GR Athens, Greece. 3: SOCIETAT CATALANA D'HERPETOLOGIA, Museu de Ciències Naturals de Barcelona. Plaça Leonardo da Vinci 4-5, Barcelona. ABSTRACT This note presents the first evidence of the existence of a breeding population of the invasive terrapine species Trachemys scripta elegans and the first observation of hatchlings at the area of Kaiafa Lake in western Peloponnese, Greece. Eleven hatchlings of T.scripta were observed in a single day, amongst the native Emys orbicularis and Mauremys rivulata, which is the first record of this kind in the Peloponnese Peninsula and one of the scarces evidences of possible breeding populations of Red eared-slider in Greece. KEY WORDS: Hatchlings; Kaiafa Lake; Peloponnese; Trachemys scripta elegans. RESUM Aquesta nota presenta la primera evidència de l'existència d'una població reproductora de la tortuga invasora Trachemys scripta elegans i la primera observació de cries a l'àrea del llac Kaiafa, al Peloponès oriental, Grècia. Onze cries de T.scripta van ser localitzades en un sol dia, entre les poblacions natives d'emys orbicularis i Mauremys rivulata, el que suposa la primera troballa d'aquest tipus a la Península del Peloponès i una de les escasses evidències d'una possible població reproductora de la tortuga d'aigua americana a Grècia. PARAULES CLAU: Cries; llac Kafaia; Peloponès; Trachemys scripta elegans. INTRODUCTION The Red eared-slider Trachemys scripta elegans is a freshwater aquatic terrapin of the order Testudine, family Emydidae, with native range in the Mississippi Valley, distributed from Illinois down through the Gulf of Mexico, and from West Virginia to New Mexico (BURGUER, 2009). T. scripta is one of the most common invasive terrapin species of Europe (SALZBERG, 1995, 1998; LOWE et al., 2000; TELECKY, 2001). According to the literature, this species was introduced in most of Europe and has been discovered to be breeding in several locations (SPEYBROECK et al., 2016). Reproduction is known in France (CADI et al., 2004), Spain (PÉREZ-SANTIGOSA et al., 2008), Calabria (CRESCENTE et al., 2014), Portugal (MARTINS et

2 al., 2017) and suggested in Serbia (DORDEVIC and ANDELKOVIC, 2015) and island of Kos (BRUEKERS et al. 2006). Outside Europe it has introduced breeding populations in Florida, California, New York, South Africa, Reunion island and Bahrein (RIVERA et al., 2011). Despite the UE banned the importation of T. scripta elegans in 1997 alone, during recent years other subspecies of T. scripta have been introduced, and some of them released, so many likely hybrids of these can be found in nature. Hybrid specimens have already been found in Spain (VALDEÓN et al., 2010) and Austria (KLEEWEIN, 2014). In 2014 the European Regulation 1143/2014 forbade the introduction of T. scripta including all sub-species. Despite the implementation of the law it is easy to find them in large numbers in the Greek pet store trade until today. In fact T. scripta is the most common available reptile in the Greek pet shops. Nowadays T. scripta is expected to be present around all Greek cities that have pet shops and urban parks with ponds (ADAMOPOULOU et al., 2016). In Greece, T. scripta has been introduced in Corfu, Crete, Kos, Zakynthos, Athens, Thessaloniki, Halkidiki and some parts of Peloponnese (BRUEKERS 1993; BRUEKERS et al.; 2006; ZENETOS et al.; 2009; UROSECIC, 2014; ADAMOPOULOU et al., 2016). C. Adamopolou and A. Legakis compile 24 sightings of T. scripta from the whole Greece, mainly around Athens and Crete, including 2 data from Peloponnese (ADAMOPOULOU et al., 2016). The distribution of the species is not clearly known in Peloponnese and demands surveying for an updated database. The published data about breeding populations or evidence of nests or hatchling of Trachemys scripta in Greece are very scarce. In fact we only know two references, one from Kos island (BRUEKERS et al., 2006) and another, indirect, from Kipos Dioumidos (near Athens) (Lourida, 2014 in ADAMOPOULOU et al., 2016). Both seem to be ignored or rejected by these latest authors, because the size of the hatchlings (4 cm) was compatible with released specimens from captive source. STUDY SITE Kaiafa Lake is the second biggest wetland in the wider region of the prefecture of Ilia, with an area of 1500 acres, reaching three kilometers long and two meters deep. Kaiafa Lake seems to hold one of the biggest populations of Emys orbicularis and Mauremys rivulata in Western Peloponnese. The lake is located in the western part of Peloponnese and was registered as Natura 2000 network. Kaiafa lake is surrounded by a pine forest (Pinus halepensis) and, nearby in the western edge, has a small dune strip by the sea. At the eastern edge of the lake the reeds (Phragmites australis) occupy the shore followed by eucalyptus trees in the mainland. The two autochthonous turtles live in the canals around the lake, but are mostly observed in the open lake area, especially E. orbicularis, while M. rivulata is easier to see in the sulfur water channels near the facilities of the old spa. RESULTS On 18 July 2005 the second author observed for the first time a female T. scripta basking in the Kaiafa Lake ( , ) at 19:00 p.m., and on 30 July 2017 the first author observed a subadult basking in the eastern edge of the lake (Fig. 1; , ) at 20:32 p.m. Unfortunately in both cases the terrapins hid in the water when they spotted us. One year after the latter observation, in 19 May 2018, we visited the lake again, this time for the herping photography and we observed for the first time ten hatchlings of T. scripta basking in the eastern edge (Fig. 2; , ) and one in the western edge within one hour of search. The ten hatchlings were found close to each other accompanied by a hatchling of E. orbicularis and two hatchlings of M. rivulata not far from a large sandy area among the reed which is probably the nesting site. The hatchlings varied in size, so probably were from different clutches. This is the first confirmed observation of a breeding population in Peloponnese. No adult individuals of T. scripta were found. In the eastern canal we found twelve adults of E. orbicularis and four adults of M. rivulata. Other herps species observed in the 29

3 lake were Pelophylax epeiroticus and Natrix tessellata. Inside the lake there is also the islet of Sainte Catherine, where the second author observed in 13 June 2010 seven empty soft-shell eggs (Fig. 3; , ) of an undetermined reptile. We now believe that the unknown eggs were probably of T. scripta. We have no measurements of the eggs, but they were certainly larger than that of lacertid eggs and similar in size to the native turtles. They also seemed to belong to an alien terrapin like T. scripta because of their soft-shell nature, in contrast with the E. orbicularis and M. rivulata hard-shell eggs. DISCUSSION The finding in only one hour of 11 hatchlings of T. scripta elegans, most of them rather close to each other in a small area, allow us to state the existence, with sound probability, of a breeding population of red-eared-slider Trachemys scripta elegans in Kaiafa lake (Peloponnese, Greece). The fact that we formerly found several rests of soft eggs very likely belonging to Trachemys scripta reinforce our hypotesis. The fact that those hatchlings must have been born in the year before the observation unable us to fully state in site breeding as they could originate from an intencionated release of commercial hatchlings. However this situation is highly unlikely as hatchlings have commercial value. Anyway, we will continue monitoring the lake in order to find new nests or newly born hatchlings of Trachemys scripta, with umbilical scar, to finally prove our thesis. In case these evidences are accepted it would be the first breeding population of this invasive terrapin found in Peloponnese and one of the few known in the whole Greece. OTHER DATA ABOUT TRACHEMYS IN PELOPONNESE The first is in the wetland of Elos Aguias ( , ), in Patras city, from an adult female that lived trapped in an abandoned swimming pool. This specimen was observed only one time, in 2015, and was never found again. The second record was about two adult Trachemys scripta reported by the second author (2014) at Tsivlos Lake ( , ), in Achaia. Those specific individuals were observed again in 2015 and EPILOGUE During the last years, autochthonous turtles have declined in Kaiafa Lake due to illegal fish trapping inside the canals. Fishermen constantly attempt to capture freshwater fish, therefore a lot of observations of dead turtles trapped in the handmade equipment have been recorded. The turtles seem to get trapped and die from asphyxiation. We often meet tourists feeding the autochthonous turtles in this area but we have never observed an adult T. scripta coexisting with the autochthonous adult turtles. Adult specimens of T. scripta seem to be shyer when found in small densities. Finally, it is important to note that introduced species like T. scripta have negative effects in the native turtle species and could cause the transmission of pathogens to them (HIDALGO- VILA et al.; 2009; ÇIÇEK et al., 2015). Finally, the allowance of a stable alien terrapin population increases the risk of releasing conspecific captives by locals ( call effect ), with the added risk mentioned. ACKNOWLEDGEMENTS We would like to thank Marios Vergetopoulos and Kiriakos Galanis for their help in the field of all this years and their great company. We have got two more observations in different areas of the Peloponnese. 30

4 Figure 1.- The second observation of the subadult Trachemys scripta in 30 July 2017 resting with three Pelophylax epeiroticus in the eastern part of Kaiafa Lake. Photo: E. Tzoras. Figure 2.- Trachemys scripta hatchling from Kaiafa Lake. Photo: E. Tzoras. Figure 3.- Seven soft-shell eggs of an unknown reptile in 13 June 2010, most probably belonging to Trachemys scripta. Photo: G. Chiras. 31

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