Franklin's Ground Squirrels (Spermophilus franklinii) preyed on eggs in 29 of 30 tests in which they were exposed to two Mallard (Anas platyrhynchos) or two Blue-winged Teal (A. discors) eggs and their discovery of eggs was confirmed. No Richardson's (S. richardsonii) or Thirteen-lined (S. tridecemlineatus) ground squirrels preyed on eggs in 104 and 54 similar tests, respectively. Franklin's Ground Squirrels exposed to clutches of six duck eggs placed in simulated nests preyed on all such clutches. Predation on simulated nests began soon after eggs were discovered, but predation of all eggs often took more than one day to complete.
Additional publication details
Responses of three prairie ground squirrel species, Spermophilus franklinii, S. richardsonii, and S. tridecemlineatus, to duck eggs