A very good but slow to deploy hawk shelter is a thick stand of large bamboo canes. A patch about 100 foot long, by 30 foot wide, and up to 20 feet tall makes a good refuge from most daytime flying pest as well as quite a few daytime 4 legged pests like foxes, or other K9s that must chase down their chicken dinners. You are also creating a cool and shady spot for your birds to idle away the hazy, lazy, days of Summer.