Common swift that resemble a crescent or a boomerang. Their call is a loud scream in two different tone pitches, the higher of which issues from the female. They often form 'screaming parties' during summer evenings, when 10–20 swifts will gather in flight around their nesting area, calling out and being answered by nesting swifts. Larger "screaming parties" are formed at higher altitudes, especially late in the breeding season. The purpose of these parties is uncertain, but may include ascending to sleep on the wing, while still breeding adults tend to spend the night in the nest. Swifts may nest in former
The Summer Birds homes and prepare to begin a new term at school. "The Summer Birds" was highly acclaimed by reviewers on its release, with some reviewers understandably comparing it to J. M. Barrie's "Peter Pan", as both books feature themes such as flying and unending childhood. Hugh Crago reviewed the book in "Signal", writing, ""The Summer Birds" is "Peter Pan" pared down, the whimsy, the sentimentality and the extravagant pantomime mythmaking cut away, leaving the essential core of genuine wonder..." In 1963, Marion R. Hewitt reviewed the book in an article about Penelope Farmer in "The Junior Bookshelf". She writes that the