While spotlighting for rabbits / foxes with a mate, we had left the cover of trees and vegetation and entered a grassy, flat paddock of which no stock was grazing. We used an "aussie button" type of fox whistle, and as we were sweeping with the spotlight we caught a pair of blue eyes in the light. They were a fair distance away, I would estimate maybe 250 meters, about the maximum range of both the .22 and the spotlight. We had no idea what we were looking at, the eyes were slightly wider apart than a fox's and would lope forwards and then crouch down. We attempted to close the distance, as we had trouble seeing the animal's outline from such range, but I am sure that by then whatever it was knew that we were no rabbit in distress, and just melted into the long grass in the distance. We discussed this encounter when we got back to the house, and tried to think of what it could have been. Kangaroos, wallabies, deer and rabbits don't come to a predator whistle. This only leaves foxes. The problem is, that foxes eyes appear a distinct red in spotlights.