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 children. A second book, "Emma in Winter", set roughly one and a half years later, with Emma as the main character, followed in 1966. "Charlotte Sometimes" followed in 1969, set slightly before the events of "Emma in Winter", which follows Charlotte's first term at boarding school. The Summer Birds The Summer Birds is a children's novel by British writer Penelope Farmer, published in 1962 by Chatto & Windus, and receiving a Carnegie Medal commendation. It is the first of three books featuring the Makepeace sisters, Charlotte and Emma, These three books are sometimes known as the "Aviary Hall" books. At