The American kestrel (Falco sparverius), sometimes colloquially known as the sparrow hawk, is a small falcon, and the only kestrel found in the Americas. It is the most common falcon in North America, and is found in a wide variety of habitats.
A brilliant bird, common in Arizona, that "team hunts." Four or five Harris hawks will pursue one critter, until it's exhausted and basically collapses. Then, it's a free for all among the pursuers for the spoils.