Endangered Sousliks tagged with radio transmitters for the first time in Bulgaria


© Dimitar Gradinarov

In July, the Bulgarian Society for the Protection of Birds (BSPB), in the framework of the LIFE project "Land for Life", tagged 25 European sousliks with specially designed collars with radio transmitters. The activity was part of the translocation of 96 representatives of the species for the conservation of a threatened with extinction colony in the Zapadna Strandzha Special Protection Area.

This is the last known colony of European sousliks in the area where only about 10 adult individuals have remained. The translocation of sousliks from another colony will preserve the chance of survival of this last remaining colony in the area. The translocation is being made to protect this globally endangered species, but also due to the fact that sousliks are an important nutritional component in the diet of another globally endangered species - the Imperial eagle for which BSPB performs special conservation activities.

The captured mammals are taken from a colony in an area near the town of Sliven, which is also threatened because of the plowing of the pastures. During plowing, many sousliks have been directly killed. The survivors are deprived of habitat and are easy prey of wandering dogs and other predators due to lack of shelter. Sousliks that have been captured and translocated have a better chance of surviving in the new place.

The captured individuals were measured, marked with a microchip and some of them were additionally tagged with a radio transmitter for the application of modern radio telemetric methods. The radio telemetry is a widely used method for exploring the spatial behavior of endangered animal species. This method is most commonly used in large mammals such as lions, tigers, rhinoceroses, bears, wolves, and less common in small mammals. Within the framework of the project for the first time in Bulgaria small mammals have been tagged with collars with radio transmitters in order to protect them. The radio telemetry results will help to study the behavior and adaptation of the sousliks during the translocation. The captured individuals were also tested for parasites and blood samples for DNA analysis were also taken.

Methods with individual cells during the release of the sousliks were used for the first time, which reduces the stress of the animals during adaptation and prevents them from predators in the most critical first days in the new place.

The project team traces the behavior and movement of the animals. In this moment the released sousliks keep close to the release area, occupying abandoned holes of the local colony.

BSPB carries out this activity with the help of Dr. Yordan Koshev, leading species expert in Bulgaria, and Ph.D. student Maria Kachamakova from the Institute of Biodiversity and Ecosystem Research - BAS.