On the southern edge of the Ljubljana Marshes, in the Draga Valley, there are ponds teeming with life. Apart from many species of birds, fish and plants, they are also home to the only freshwater turtle native to Slovenia, the European pond turtle. Since it faces many threats, efforts are being made to protect it.

The ponds in the Draga Valley near the town of Ig are a paradise for those who love nature and tranquillity. Just a half-hour drive from the centre of Ljubljana, one no longer hears the honking of cars, only bird chirping. The Great Pond immediately comes to view, surrounded by lush vegetation, the water glimmering in the early morning sun.

"It's good we got here so early so we won't be too hot," says Ana Tratnik, a nature conservationist from the Ljubljana Marshes Nature Park, who took us to the pond. As part of the Life Urca Proemys project, she is involved in monitoring the European pond turtle, also known as European pond terrapin, in this nature reserve.

The project, launched in October 2022 and running until September 2027, aims to improve the status of their populations in Italy and Slovenia through a long-term programme of measures in 55 Natura 2000 sites. Eight Italian and two Slovenian partners are involved, the Ljubljana Marshes Nature Park and the Sečovlje Saltpans Nature Park.

The European pond turtle (Emys orbicularis) is the only native freshwater turtle in Slovenia. Its Slovenian name močvirska sklednica roughly translates as "swamp bowl" due to its bowl-shaped shell, and the turtle is most easily recognised by the numerous yellow spots all over its body. It lives in southern and central Europe, west Asia and north Africa, and its habitat is wetlands such as ponds, swamps, lakes and rivers. As an endangered species, it is protected nationally and internationally.

More than one threat

As Tratnik explains, its populations have declined sharply due to numerous threats. The main ones are the alteration, fragmentation and loss of natural habitat due to pollution, deforestation around wetlands, and other encroachments on nature. Another problem are invasive non-native turtles, especially yellow-necked and red-necked turtles, that have been introduced into the wild by people.

"These non-native turtles are much larger than the pond turtle. They can weigh up to three kilos, while pond turtles only reach about a kilo," says Tratnik. The non-native turtles deprive the native species of food and sunbathing areas, while they can also carry dangerous diseases and parasites. However, in the ponds in the Draga Valley predators are the main threat, says Tratnik.

"We've repeatedly observed turtles successfully lying eggs, but various predators have dug them up and eaten them. As a result, the age structure of the pond turtle has changed considerably. They usually live between 40 and 60 years, and can reach 100 years in exceptional cases, which means they can be very old. However, due to the predators, there are not as many young turtles, which leads to a rather uneven age structure."

Nest protection key

As part of the project, nature conservationists from the Ljubljana Marshes Nature Park are thus taking action to protect their nests.

"Since last year, we've been monitoring six adult females to whom we attached transmitters. Until the end of the project, every spring or early summer when the pond turtles lay eggs, we will be monitoring where they lay them and protect these nests with a special net," says Tratnik.

At the same time she pointed an antenna towards the pond. "This device shows us where the tagged turtles are at the moment. The higher the number on the monitor, the closer the turtle is."

In two years, 18 nests have been protected in the Draga Valley, ten last year and eight this year. However, there are probably more nests, says Tratnik.

"When we were doing the monitoring in the evening, we found more females than nests. We assume that some of the females are laying eggs overnight or early in the morning, but they could also be in an area we were not paying attention to. Quite a few of the turtles we saw did not have transmitters."

In one of the nests protected last year, eleven little turtles hatched this year and dug themselves out of the nest. "They had to work their way through about five centimetres of soil, which is very impressive for such small turtles," says Tratnik.

Yet not all eggs in the protected nests hatched last year, presumably because they were flooded during last year's storms. However, it is not really known exactly how well the turtles hatch in the wild.

No luck

When we walked to the meadow where most of the nests were protected, we saw no turtles, but we did see some eggshells. "We can take a peek into the traps in the pond," suggests Tratnik. We made our way through the dense vegetation as if exploring the jungle. We had to walk carefully so as not to miss a solid patch of earth and end up in the pond. High boots were therefore our must-have equipment.

There were no turtles in the traps either, which was not a big surprise, because turtles are very shy. "Even in areas where they are usually many of them, it's difficult to see them, as they are more likely to hear us and escape into the water," Tratnik says.

Interestingly, some turtles can even be found in the forest, far away from the pond and the nests, when they are looking for new habitat or going to the next body of water. "One of the tagged ones was later found almost near Grosuplje, [ten kilometres away]. We don't know whether somebody took it there or whether it did it on its own, but it's clearly a very mobile animal," says Tratnik.

Although we did not see any turtles this time, we were not disappointed. We had a view of the beautiful pond, where three herons were resting. A few dragonflies flew over our heads and we even saw a Japanese silk moth. "They were introduced a long time ago to produce silk and have spread to this area," says Tratnik.

Due to the rare plant and animal species that thrive here, the area of the ponds was declared a natural monument, and with the establishment of the Ljubljana Marshes Nature Park in 2008, the ponds were declared a nature reserve and one of the park's protected areas.

"Unfortunately, wetlands were for a long time perceived as worthless, which is why people often encroached on them. Now, they are increasingly realising how important they are for biodiversity, which projects like ours strongly contribute to, raising public awareness about the importance of preserving the habitat of the pond turtle, which is a really interesting reptile," says Tratnik.