[4] Three subspecies are known:[4] The white-tailed hawk can be found anywhere from coastal Texas and the Rio Grande Valley[5] to central Argentina, as well as many Caribbean islands of the Lesser Antilles, and Trinidad and Tobago.

[6] Its preferred hunting technique is to hover and observe the surroundings for signs of potential prey, gliding to another place when nothing is found.

Rabbits make up the majority of the hawk's diet in southern Texas, while lizards of 12 in (30 cm) in length and more are the preferred prey in the Dutch West Indies.

Other animals such as cotton rats, snakes, frogs, arthropods (especially grasshoppers, cicadas, and beetles), and smallish birds such as passerines or quails are also eaten; it will snatch chickens when no other source of food is available.

In the open cerrado of Brazil, mixed-species feeding flocks will react to a white-tailed hawk with almost as much alarm as they do when seeing such dedicated predators of birds as the aplomado falcon.

[7] The white-tailed hawk is also known to feed on carrion and to gather with other birds at brushfires to catch small animals fleeing the flames.

When approached on the nest, the adults will get airborne and observe the intruder from above, unlike related hawks, which usually wait much longer to flush and then launch a determined attack.