European ground squirrel (Spermophilus citellus, also known as the European souslik) is a species of rodent in the Sciuridae family. It has yellow-brown fur with dark spots on the back. The body length is 164-205 mm and the tail - 40-74 mm.
Bulgaria is in the southern part of this species’ distribution range. In Bulgaria the European souslik inhabits meadows, pastures, dry steppes, on the rand of cultivated fields, along roads and some spots up to 2,500 meters above sea level.
The European ground squirrel lives in colonies of several hundred animals. The species digs holes in the ground alone to use as a place for shelter, sleeping and rearing, for that purpose there are several types of holes: temporary, permanent and holes for hibernation. The European souslik can be easily seen if we stand still not far from their colony. You will see how they eat, how they run across the road, dig holes and stand straight to look around the area. If we are observant we may notice that each colony has guards. While most ground squirrels are eating, one or several animals stand upright on its hind legs and monitor the area. If they notice any danger, they warn the others by issuing an alarming whistle and all hide in the holes. Scientists have found that the ground squirrel populations from different parts of Bulgaria issue various warning sounds as if they "speak" in different dialects.
The European ground squirrel mainly feed on grass and seeds. Since the animals are most vulnerable in the open, they have developed a special feature to collect food – a pouch or a cheek bag. While it is outside, the ground squirrel stuff seeds and grass in these pouches then hide them in a hole where it is safe and then eats in peace.
Another characteristic of the souslik, is that in the winter months it falls into a winter sleep - hibernation. The hibernation is an adaptation of this species helping it to survive the adverse conditions. The ground squirrels do not collect food supplies. They use the energy accumulated in the form of fat, so in the summer and early autumn they feed actively. In Bulgaria, their hibernation lasts from September/October to the beginning of March. Before going into hibernation the animals reconstruct their holes. As soon as they wake up from hibernation in early March the European ground squirrel starts to mate. In April and May females give birth to 5 - 8 small blind and naked babies, who spent the first 4 weeks in the hole.
[color=red]The ground squirrel is an endangered species.[/color] The main threat is the destruction of its habitat. It is declared strictly as a protected species and is included in many European and Bulgarian environmental laws and conventions.