The hawk has the advantage of elevation. It can fly up and take a look around when there are a lot of obstacles, like in a forested or mountainous region. It can spot ambushes that are well-hidden from below. Even with a 180' range, it can be pretty advantageous if you aren't adventuring on a featureless plain. Plus, you've got excellent color vision, so you can get good details, and good low-light vision (enough to hunt mice in the dusk). Even sitting on the character's shoulder, the hawk's eyes would provide better sight. It's hearing range should allow it to listen in on human language conversations, possibly from further away than a human could in some circumstances. Human speech can go a bit outside their best hearing range, but birds are better at picking out sounds in noisy environments. The bird can probably perch in a convenient location where the human could not (at least not without being an obvious snoop). It's not clear how good their sense of smell is. Touch will typically be less sensitive than a human's sense of touch.
