You're undoubtedly right that they are frightened of you, for now. But usually it's not a big problem to tame them. Sit with them and let them get use to you. If they climb on your foot, put a little feed there. They will probably squawk if you pick them up from above; they have a pretty strong anti-flying predator instinct. If you lay your hand down on their litter, esp. with a little food or treat, they should start climbing on your hand. Just give them time to figure out you're the bearer of good things to eat, and not a gigantic owl or hawk. Bribery with treats is quite successful.