Planting of warm seasoned grasses and shrubs allows the quail to flee from potential predators like pictured above.  The coyote is a very stealthy hunter, and they can out smart most animals that they hunt.  Although the coyote will rob nests of its young with proper planting of shrubs the coyotes chances of spotting a nest would greatly diminish.  Most of the time the predators don't come from the ground they swoop down and take what they want then fly away.  The red tailed hawk is a superior predator that can't be controlled because they are protected by federal law.  This is where the warm native grasses come into help out.  Most native grasses can grow to an average height around 5-6 feet tall, and if your a 5-6 inch bird that creates a lot of cover.