The elf owl (Micrathene whitneyi) is a small grayish-brown owl about the size of a sparrow found in the Southwestern United States, central Mexico, and the Baja California peninsula. It has pale yellow eyes highlighted by thin white "eyebrows" and a gray bill with a horn-colored tip. The elf owl frequently inhabits woodpecker holes in saguaro cacti; it also nests in natural tree cavities. It is nocturnal and feeds primarily on insects.
Source: Wikipedia
Other members of the owls family recorded in North America — a useful place to start if you are not certain of your identification.
You don't need to spend a fortune. These four pairs will get you birding confidently on day one.
From phone adapters to dedicated rigs, here's what actually works for capturing birds in the field.