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
Osor Musical Evenings by Dodi Komanov, "Arkadija hrvatske glazbe: 30 godina festivala Osorske glazbene večeri" (Arcady of Croatian music: 30 years of Osor Musical Evenings) published by the festival in 2006. Osor Musical Evenings Osor Musical Evenings () is a Croatian classical music festival that takes place in the historical town of Osor, on the island of Cres in the Kvarner Gulf. The festival was founded in 1976 by Daniel Marušić, a renowned Croatian TV and Opera director, who was its artistic and executive director until his death in 2009. The original idea behind the festival was to revive Osor during the summer,