I see no response. Cover that is effective is not always pleasing to the eye. Trees with open under-story obscure view of soaring predators, but most I deal with will be perched in the canopy or come in a low angle from just above ground level. If the hawk can fly through, then cover will not obstruct pursuit by air or foot. Hawks are size selective and will chase small chickens into heavy bush. I shut that down with adult standard-sized roosters that will readily attack such hawks in the ground. The type of hawk I have that goes after chickens while on the ground is the Coopers Hawk. Even my game hens can run those off.
If hawk thinks a dog is nearby, then odds it will go on ground is less likely.