I don't understand why this is translated into the present perfect continuous? So far this verb tense has been translated as present continuous or simple? So I was expecting either this fox eats chickens or this fox is eating chickens.Any ideas?
Czech has only one present tense, so it has to cover a lot of ground, and context is helpful. (Unfortunately, we rarely have it.)
I would GUESS, based on what I've seen to far, that all of these could be accepted translations: EATS my chickens, IS EATING my chickens, and HAS BEEN EATING my chickens. But the learning for us in this sentence probably is that "has been XXXing" is also handled by the Czech present tense.
That's why we also accept eats and is eating. You can't tell without the context.