Protecting nest sites of European Pond Turtle (Emys orbicularis) in Ljubljana Moor in 2022 and 2023

Abstract

The European Pond Turtle (Emys orbicularis Linnaeus, 1785) is predominantly observed in marshes, ponds, and slow-flowing streams with rich vegetation. With an IUCN status of Near Threatened (NT), its population trend across Europe is exhibiting a decline. In Slovenia, it is classified as endangered (EN). Within the northern part of Ljubljana Moor is a well-known population of this species, mostly found in man-made water canals among agricultural land. Because Ljubljana Moor is under the influence of agricultural intensification, this population is threatened mostly due to the destruction of nests which the turtles dig in the soil of agricultural fields to ensure optimal sun exposure. Since 2015, the Herpetological Society – Societas herpetologica slovenica has been monitoring gravid females and protecting nesting sites. Here, we focus on the outcomes of the last two annual projects. In 2022 we marked five gravid females with radiotelemetry transmitters and later discovered and protected five nesting sites. However, the 2023 project encountered challenges related to transmitters, weather conditions and nutrias. Only four gravid females large enough were successfully captured, and no nesting sites were located. The summer of 2023 was characterized by excessive rainfall and storms, leading to widespread flooding throughout Slovenia.

Full text

Protecting nest sites of European Pond Turtle
(Emys orbicularis) in Ljubljana Moor in 2022 and 2023
Katja Konc (1,2), Ana Skledar (2), Blaž Kekec (2), Meta Valenčič (2)
1 Biotechnical faculty, University of Ljubljana, Ljubljana, Slovenia
2 Herpetological Society – Societas herpetologica slovenica, Ljubljana, Slovenia
Introduction
The European Pond Turtle (Emys orbicularis Linnaeus, 1785) inhabits marshes, ponds, and slow-flowing streams
with abundant vegetation. Listed as Near Threatened (NT) by IUCN (Tortoise & Freshwater Turtle Specialist Group,
1996), its population in Europe is declining. In Slovenia, it is classified as endangered (EN) (Uradni list Republike
Slovenije, 2002). A well-known population resides in the northern Ljubljana Moor, primarily in man-made water
canals amid agricultural land. Agricultural intensification threatens this population, particularly through the
destruction of nests and loss of habitat. Since 2015, Slovenian Herpetological Society has been monitoring gravid
females and safeguarding nest sites to protect this species.
Methods
We captured turtles by hand and using turtle traps.
In 2022, we equipped five gravid females with VHF radiotelemetry transmitters, and in
2023, we equipped four.
We tracked the turtles every evening in May and June using a SIKA receiver (Biotrack)
and Yagi antenna.
Upon locating nesting turtles, we protected their nests the following morning using a
metal net.
We conducted numerous educational workshops for children throughout both projects.
Results
In 2022, we discovered and protected five nest sites from four different females. Four nests
were located in wheat or cornfields and one in intensive grassland. During our September
checks, we found newly hatched turtles at one nest site. The 2023 project faced challenges
with transmitters, weather conditions, and nutria interference, resulting in the destruction of
12 out of 18 traps. We successfully captured only four gravid females suitable for the new
transmitters. Evening storms hampered fieldwork, and the turtles were inactive during bad
weather. The summer of 2023 was marked by excessive rainfall and storms, causing
widespread flooding across Slovenia including in Ljubljana Moor. Unfortunately, no nest sites
were found. However, in 2023, we captured many turtles aged approximately 10-15 years,
coinciding with the start of our efforts. While additional data is needed, this could indicate the
success of our conservation initiatives.
Conclusions
Successful nest protection in 2022: We
discovered and safeguarded five nest sites of
four females, with hatchlings observed at one
site.
1.
Challenges in 2023: The project faced significant
difficulties, including new heavier transmitters,
nutria interference, and adverse weather
conditions, resulting in no new nest sites being
found and reduced turtle activity in general.
2.
Positive indicators: The capture of many turtles
aged 10-15 years suggests that our conservation
efforts since 2015 may be yielding positive
results, although further data is required to
confirm this trend.
3.
Future work: Continued monitoring, improved
methodologies, and addressing the challenges
faced will be essential for the ongoing success of
our conservation initiatives.
4.
Acknowledgments
We would like to thank everyone who participated in
these two projects. We would also like to thank the
Municipality of Ljubljana for financial support.
Bibliography
Tortoise & Freshwater Turtle Specialist Group. 1996. Emys orbicularis (errata version published in 2016). The IUCN Red List of
Threatened Species 1996: e.T7717A97292665. https://dx.doi.org/10.2305/IUCN.UK.1996.RLTS.T7717A12844431.en. [29 May 2024].
Skledar A., Kekec B. (2022). Final report on the project for the protection of European Pond Turtle nest sites in Ljubljana Moor 2022.
Herpetological Society – Societas herpetologica slovenica, Ljubljana, 1-17.
Skledar A., Valenčič M. (2023). Final report on the project for the protection of European Pond Turtle nest sites in Ljubljana Moor
2023. Herpetological Society – Societas herpetologica slovenica, Ljubljana, 1-13.
Uradni list Republike Slovenije. (2002). Pravilnik o uvrstitvi ogroženih rastlinskih in živalskih vrst v rdeči seznam [Rules on the
classification of endangered plant and animal species in the red list]. Uradni list Republike Slovenije 82/2002: 8893.
Photo: Anja Pekolj
Photo: Katja Konc
Photo: Ana Skledar