sentences:  As presented in the multi-year studies from Hungary, a seeming decline of the European ground squirrel ("Spermophilus citellus") population is the cause of their reduced importance in the imperial eagle’s diet, with this species being the primary prey in 1975-1991 (51% of 606 prey items from 1975 to 1985) to contributing almost nothing in 2005-2017.It is possible with reintroductions of the European ground squirrel underway in central Europe, that this prey species may again become more significant in the eastern imperial eagle’s diet again here.In Tyva Republic, the long-tailed ground squirrel ("Spermophilus undulatus") still dominates the food of imperial eagles, making up 60.1% of 168 prey items.