Merlins are members of the falcon family, a group of birds known as the fastest birds of prey. Despite their small size, Merlins often cruise at speeds reaching up to seventy-two kilometres per hour. To learn the flight pattern of a Merlin, all you have to do is watch a pigeon. The Merlin's Latin name Falco columbarius translates to "dove-like hawk". This is in reference to the fact that it often resembles a pigeon in flight, as both birds have similar wing shape and fly with the same rapid wing beats.

The favourite habitats of the Merlin are shorelines and open coniferous forests. Nearly ninety percent of the Merlin's diet consists of birds. During the winter months they will frequently visit backyards that have feeders in open areas. Unlike the Sharp-shinned Hawk, the Merlin, in order to be successful, must catch its prey in the open and almost always on the wing (in flight). Although the Merlin is only slightly bigger than the Sharp-shinned Hawk, its greater power allows it to feed on larger species of birds. Most of the Merlin's diet consists of birds between the size of a Blue Jay and an American Robin. If you wish to discourage a Merlin from preying on the birds at your feeders, you can move the feeders closer to shrubs or trees. Bear in mind that predation by Merlins is natural. By moving your feeder closer to cover, you make bird-hunting easier for domestic cats.

Noting the flight pattern and hunting method is the best way to separate the Merlin from the similar looking Sharp-shinned Hawk. Merlins are restless birds so you are unlikely to see one sitting in your yard, but if you do, be sure and note its facial pattern. Merlins can be recognized in all plumages by a dark line that runs down the face from the eye. In bird books, this line is often referred to as a mustache or occasionally as sideburns. The male Merlin sports a gray-blue back while the backs of females and immatures are brown.