Hawk Vision: at 500ft hawks can see about 27 square miles, at 1000 they can see about 39, at 5000: 86, and at 10000: 122. Hawks usually are at between 2300 and 4600 ft at the height of the day heat. Vultures reach 10,000 feet–their rocking motion enables them to climb much higher than other hawks.
Kiting: hanging motionless in the wind
Hovering: flapping in one spot
Kettles of birds may contain more than one type of bird as many are attracted to the thermal.