World Turtle Day
🐢 World Turtle Day 🐢
#WorldTurtleDay
It was established by the non-profit organisation American Tortoise Rescue (ATR) in 1990, with the aim of raising awareness of the importance of turtle protection.
Turtles, Chelonia or Testudines, are the oldest living group of reptiles today.
It was once believed that they were also the oldest group of amniotes, organisms whose eggs have additional membranes. The development of such eggs enabled vertebrates to live outside water and colonise terrestrial habitats. Fish and amphibians, for example, are anamniotes, meaning that their eggs must develop in water.
According to currently accepted evolutionary theories, turtles are not the oldest amniotes after all, although this was believed until recently; instead, the direct ancestors of today’s mammals hold that position.
According to The Reptilia Database, a total of 354 turtle species are known today, divided into 2 suborders, Cryptodira – hidden-necked turtles and Pleurodira – side-necked turtles, with a total of 13 families. Of these, only 6 species are native to Croatia.
There are three terrestrial species: Hermann’s tortoise, Testudo hermanni, the European pond turtle, Emys orbicularis, and the Balkan terrapin, Mauremys rivulata.
In Croatia, Hermann’s tortoise inhabits terrestrial habitats in coastal regions. It is most often found in maquis and rocky grasslands from Istria to southern Croatia.
The European pond turtle and the Balkan terrapin live in various types of inland waters. The European pond turtle is widely distributed in Croatia, while the Balkan terrapin inhabits only the southernmost parts of Croatia, from the Baćina Lakes southwards.
In addition to them, three marine species have been recorded in the Croatian part of the Adriatic Sea: the loggerhead turtle, Caretta caretta, the green turtle, Chelonia mydas, and the leatherback turtle, Dermochelys coriacea.
Of these, only the loggerhead turtle is a permanent member of our fauna, while the other two species occasionally visit the Adriatic Sea. However, even for the loggerhead turtle, there are no records of it using sandy beaches along our coast for laying eggs.
In the inland waters of Croatia, the following non-native, allochthonous, turtle species and subspecies have been recorded:
🔸 red-eared slider, Trachemys scripta elegans
🔸 yellow-bellied slider, Trachemys scripta scripta
🔸 false map turtles, Graptemys pseudogeographica kohnii and Graptemys pseudogeographica pseudogeographica
🔸 Chinese softshell turtle, Pelodiscus sinensis
While most of the listed species have been found in Croatia at only 1 to 3 locations, records of red-eared sliders, Trachemys scripta elegans, are known throughout Croatia.
This is a consequence of the fact that this species, once very popular as a pet, was irresponsibly released into nature by owners. In habitats where its presence has been recorded, it most often threatens the survival of the native European pond turtle.
As in the rest of the world, terrestrial turtles in Croatia are most threatened by changes in their natural habitats, such as the drainage of wetlands, disappearance of ponds, pools, oxbow lakes and fishponds, river canalisation, urbanisation and similar changes, as well as by the introduction of invasive alien species or hunting for food and sale.
Sea turtles, on the other hand, are threatened by pollution of the sea with various types of waste, especially plastic waste, fishing trawlers, propellers of fast motor yachts and similar threats.
Our most endangered species is the Balkan terrapin.
Its population in natural habitats in southern Croatia is estimated at around 1,000 individuals.
Prepared by: Eduard Kletečki