I doubt they will chase you in the sky, why would they want to? Besides, chicken like birds can't fly that high compared to a proper bird. They'll proberly be in Skyloft or one of the floating islands somewhere. Other than those places I can't see them anywhere else.
Im pretty sure Cuccos will be in Skyward Sword . There are obvious places where they'll be. In Skyloft for sure and probably on some of the floating islands in the sky where maybe you'll need them to reach other places on said Islands. And who knows they might be in the land below but from what I've seen so far it doesn't look like there will be a sprawling overworld in the land below. Doesn't mean that the areas you drop into wont be huge. So then Cuccos are a high possibility for me.
Im sure they'll be in somehow, but I dont get why people think that if something is not in this game that it wont make sense for future games, its like real life...chickens are in famrs everywhere I eat chicken lol, but Ive probably seen a chicken 4-5 times in my 26 years of life.
Hopefully, there will be cuccos in Skyloft or somewhere on the world below. It'd be cool to see some different varieties as well, like the brown cuccos from Twilight Princess. I hope they make an appearance in Skyward Sword; I missed those little guys in the Wind Waker.
Although it would be fun to play with, I doubt we would be seeing them in this game. I think the sailcloth has taken the place of the cuckoo as far as a quick item that could help you float slowly towards other locations. Cuckoos do not seem as necessary anymore when Link carries an item that helps him to float in the air that could be used at any time. Much like the Deku Leaf in WW, another game that did not have any cuckoos but had an item that took their place.
However it would still be fun to find them somewhere, maybe just a tiny farm on skyloft where you can pick on them like before. I'm sure for a village like that they have to have some kind of livestock around. And chickens make a little bit more sense than almost anything else given the very limited amount of space they have to live on and resources available. Plus a cuckoo might be capable of remaining on the island while a pig might fall off a little too easily.
I think they'll transform into a white chicken form of your Loft Bird and swarm around you and when they completely surrond you you get sent backt to wherever you started flying and you lose 1 and a half hearts.<3 They're everywhere!!!!! :shield::mastersword::fairy: