European Souslik (Spermophylus citellus) close-up of head, Bulgaria

animals souslik eastern european east horizontal fields east europe east european vertebrate endotherm mammal developed country ground europe field eastern european head nature mammalia close up zoology sousliks developed countries european citellus ground europe fauna sousliks horizontals rodentia bulgaria mammal endothermic wildlife eastern europe bulgarian grasses warm blooded warm vertebrates squirrel sciuridae blooded mammals spermophylus animal grass animal