Okay So the post before me was about the hurley Bird and I came up with an explanation that I thought I would share with all of you to get some feedback, and some possible other theories.
Just so we all know what the Hurley Bird is Go type it in to the search Bar. It is a giant Parrot like bird that has shown up twice, in the first 2 season finales I believe, and it has been confirmed it screeches Hurley's name.
So here is my explanation as to why I think this is happening.
When Hurley went back in to 1977 and joined Dharma, thanks to the biggest bad ass of them all, Sawyer. Anyway, in a probable not shown scene, Hurley could have possibly encountered this bird as a baby and may have fed it and taught it to say his name. Now years later, after the crash of flight 815, the bird sees Hurley and remembers him And this is why it screeches his name.
As for Hurley not remembering the bird when he sees it, It is because in his time line as he encountered it, he had not yet time traveled back to 77.
Another theory is that it is a scout for smokey, Seeing as how both times we see the bird the monster comes afterward's. But this does nothing to explain why it knows his name.