Family Micropodide
SWIFTS.
The seventy-five known species of Swifts are distributed throughout the greater part of the world. About one half this number are American, but only four are found in North America. Swifts are generally found associated in scattered companies, and when roosting or nesting are eminently gregarious. Hollow trees and caves are their natural retreats, but in some parts of the world chimneys are now used exclusively.
They feed entirely while flying, and with their unusually long wings and small, compactly feathered bodies possess unrivaled powers of flight. Swifts are popularly confused with Swallows, but the resemblance is only superficial and exists chiefly in the similarity of their feeding habits, while the structural differences between the two are numerous and important. 423. Chætura pelagica (Linn.). CHIMNEY SWIFT; CHIMNEY "SWALLOW." (See Fig. 39.) Ad. - Entire plumage fuscous, more grayish on the throat; a sooty black spot before the eye; shafts of the tail-feathers extending beyond the vanes. L., 5.43; W., 4.94; T., 1.90; B. from N., 15.