This section is from the book "The Balance Of Nature And Modern Conditions Of Cultivation", by George Abbey. Also available from Amazon: The Balance Of Nature And Modern Conditions Of Cultivation.
The Common Swift (Cypselus apus) is generally included in the family of Insessorial birds. Hirundinidae or Swallows, of which it is made to form one of the sub-family Cypselinae, but by some naturalists is considered more closely allied to the Goatsuckers. Its colour is a sombre or sooty black, a whitish patch appearing beneath the chin. The beak is black, and the " gape " or opening of the mouth exceedingly wide. It flies abroad chiefly in the morning and evening hours, and is readily distinguished by the peculiar swift, shooting flight, and shrill cry. It arrives in this country in May and departs about the end of August. The nest is built in steeples and other elevated situations, and is composed of grass, straws, feathers, etc. The eggs, numbering two to five, are of a white colour. A single brood only is produced each year, and is hatched about the end of June or beginning of July. The food consists wholly of insects captured on the wing.