European Souslik (Spermophylus citellus) sat on haunches looking inquisitive, Bulgaria

animals souslik eastern european east fields east europe east european vertebrate endotherm mammal developed country ground europe field eastern european nature vertical mammalia zoology sousliks developed countries european citellus verticals ground europe rodent fauna sousliks rodentia bulgaria mammal endothermic wildlife eastern europe bulgarian grasses warm blooded warm vertebrates squirrel sciuridae blooded mammals haunches inquisitive spermophylus sat animal grass animal