If you can, possibly, plant some really dense evergreens like Berberis 'William Penn' or some other low bushes, the birds will dive into them whenever they sense danger. My feeder is near some hemlocks and they use them. Hawks are common and sharpshin hawks nest here, but still the birds are doing well.

I have hawks that show up and go after 'my' squirrels and birds and such. The hawks are beautiful, but... well, I wish they'd move along and hunt elsewhere.

I keep a very loud, shrill push-button electronic whistle attached to my purse, and it has worked in out-shrieking hawks when I see or hear one perched overhead. It's a personal security alarm gadget -- I'll find the link to same and post it below.

Also, if I feel threatened by a bold hawk, I wear a hat if I have to walk under it...they've been known to attack some people if they feel so inclined.

Re the link: I don't think this is the same site that I bought my whistle from, but what I have is like the 'Item HP-388.'

Oh... I'll add this... the whistle has also helped me scare away some kind of critter that was inside the walls of the house. (I know they'll never really be gone, but... I want them to know it's not THEIR place!)

Here is a link that might be useful: whistle to shoo away hawks

Interesting point people often overlook: Squirrels, grackles and jays feast on bird eggs in the summer, thereby actually having a bigger effect on songird populations than the hawks, that take birds here and there (not emptying a nest). So to artificially boost the population of squirrels, grackles and jays, and not to have hawks cull the populations, creates more songbird mortality than the hawks themselves.

I saw a hawk grab a bird from my feeder area about a week ago. I was momentarily stunned -- it happened so fast. I'm hoping it was an English sparrow. However, I haven't found that this has kept songbirds from my feeders. I guess I feel that the hawks are beautiful also, and as long as they don't drive away all the songbirds, I can live with them.