Tree Swifts: Hemiprocnidae

The head-to-tail length of tree swifts ranges from 5.8 to 11.5 inches (15 to 30 centimeters). Birds weigh from 0.8 to 2.9 ounces (21 to 79 grams). Tree swifts have long wings and tails that are forked and divided into two sections so that they resemble the letter V turned on its side. Tree swifts fly quickly when hunting food, but they live in one area and usually do not migrate.

Tree swifts belong to the Apodiformes order that also includes swifts and hummingbirds. While all the birds share some physical characteristics, swifts and hummingbirds have weak feet and do little perching, sitting or standing on a surface. Instead, they spend much of their time in the air. Tree swifts have stronger legs and are able to perch in trees.

Swifts have mostly gray plumage, feathers. Tree swifts and hummingbirds are more colorful. Tree swifts have patches of color in their plumage. Some birds have whiskers. Other birds have a crest, a group of feathers that stand upright on their foreheads.

Some species characteristics are described by the birds' names. The crested tree swift has a crest. The gray-rumped tree swift has gray plumage on its rump. The moustached tree swift has a white "moustache," white plumage that extends from the chin to the back of the neck. The whiskered tree swift has long feathers that extend from the face like whiskers. The bird is also known as the lesser tree swift.