The natural environment of each country is inhabited by native animals. Sometimes the balance is disturbed by the introduction of invasive alien species (IAS) originated from different parts of world. This also applies to freshwater turtles, which are often released to local rivers and other water reservoirs. They have become IAS, causing serious damage to ecosystems, crops and autochthonous species (e.g. European pond turtle Emys orbicularis). Moreover, they can be both the reservoir and vector of microorganisms pathogenic for animals and humans.
The aim of the study was the assess the movement of the invasive turtle species in local ecosystems in Eastern Poland using the telemetry method.
Turtles (Trachemys scripta elegans, n=6 and Trachemys scripta trootsii, n=1) caught in different parts of Lubelskie voivodship (Eastern Poland) were selected for telemetric research. The animals were equipped with GPS/GSM transmitters (Saker-T, Ecotone Telemetry, Poland) and released to the environment (rivers and an artificial lake) at original trapping sites.
The signals were collected and transferred to maps using ArcGIS (ESRI) and Google Earth. Geographical coordinates of the turtles no 113, 203, 204 and 309 showed that the animals did not move away from the trapping site. In case of the remaining turtles, the duration of signal transmission varied from a few days to several months. Geographical coordinates of the turtle 101 showed a significant distance of movement downstream the Bystrzyca river, interrupted with periods of long stopovers. During the observation period the turtle moved forward about 4.18 km from the place of release in a straight line. Interestingly, the turtle 101 transmitted signals from 12.08.2015 to 24.09.2015 and then, unexpectedly, resumed transmission from 05.04.2016 to 02.10.2016. The interim period coincided with the decrease of temperatures below 5-10°C and the disappearance of signal can be explained by the hibernation of the turtle in the environment. The analysis of movement range in 2016 clearly suggested that the turtle was alive. The movement range of the turtles 228 and 332, released to the Vistula and Wieprz rivers, varied from 1.87 to 2 km in a straight line.
The conducted unique telemetric studies showed that the invasive turtles native to North and Central America can survive winter in Eastern Europe. They are sedentary but occasionally can show mobility, especially in rivers, thus posing threat to the balance of local ecosystems.
This work was supported by the National Science Centre project “Invasive turtle species as a source and vector of animal and human pathogens” (Grant No. 2013/11/B/NZ7/01690)
Topics: Social-ecological systems as a framework for conservation management , Topics: Management of Human-Wildlife Conflicts: “Other” Species in Europe , Topics: Natural Resource and Conservation Stakeholders: Managing Expectations and Engageme
