Of course, as most raptors, squirrels, mice, snakes, grasshoppers, and other small animals are included in their diet. Male Merlins are blue-gray above, white below with streaked breasts. The tail is barred. Females and immatures are brownish above, but otherwise similar. The coastal form is especially dark and heavily streaked.
Merlins lack the heavy mustache mark present in many other falcons.
Several other hawks and falcons may be mistaken for Merlins. These include Peregrine Falcon, American Kestrel, and even Sharp-shinned and Cooper's Hawk. Merlins, as falcons, have sharply pointed wings, unlike the broad rounded wings of Cooper's and Sharp-shinned Hawks. American Kestrels have a rusty back and tail. They also have a bold whisker mark, and a second mark down from they ear.