What is the meaning of the two dead hawks in The Alchemist?
As in much of this story, this question is a matter of interpretation. Keeping in mind the nature of the story's theme, i.e., identifying and following one's personal legend, the reader can come to certain conclusions.
The scene involving the dead hawks comes on the heels of Santiago coming face to face with The Alchemist. The Alchemist rides in on horse amidst a swirling sea of dust. It's quite a vivid scene. The hawks are an omen. Like so many omens presented throughout the book, it's up to Santiago (and the reader) to look for meaning.
Hawks are birds of prey. As such, they aggressively hunt for their food. As birds, they have the ability to fly. They can "search" for what they need. And isn't this what Santiago himself has been doing in the novel? Searching for his "food?" Presenting these birds of prey as dead serves as a reminder that even with their "power" (attributes), they still are living creatures with limits to their power. Santiago must learn from them that, even in his quest for his personal legend, he must use caution while utilizing his newly enhanced "power" of sight. Like the hawks, he too has gained an ability to "see beyond." Like too, he must also keep in mind that just seeing is not enough. His actions must be predicated on using his sight to see what others overlook, else his insight/power will have been obtained for naught.