The merlin is a medium-sized falcon, larger than an American kestrel and more heavily streaked overall. Its streakiness makes it look very dark. In flight, the merlin is a direct and speedy flier, and it rarely hovers (as kestrels do) or perches in one place for extended periods.
A high-pitched kii-kii-kii-kii.
The male is dark above and the female is brown above, and both are heavily streaked with brown below. Some birds show a dark mustache and hood. The merlin lacks the bold facial marks of the larger peregrine falcon and the rusty coloration of the smaller American kestrel.
Prefers open country in all seasons, including prairies, beaches, shorelines, and marshes. The merlin is increasingly common in towns and cities, especially in the Great Plains. It is more common in the West, although populations are increasing in the East.
A merlin may visit your backyard feeders looking for a bird to eat, but this is not a common occurrence (as it is with more regular backyard hunters such as sharp-shinned and Cooper’s hawks).