Sounds and Vocal Behavior

The vocalizations of the White-collared Swift are described as "thin hisses, squeals, and chittering" (Hilty and Brown 1986); as "loud, screeching, and chattering cries, [that] may recall parakeets" (Howell and Webb 1995); and as a "nasal twitter of chee chee chee, whiss whiss, and "scratchy but not shrill tseet, tchee, and chirrio notes" (Fjeldså and Krabbe 1990). Members of a flock  may call in unison (Slud 1964, Hilty 2003, Schulenberg et al. 2007).

A flock in rapid descent, as when "descending at high speed down [mountain] valleys" can produce "an impressive swooshing rush of air" (Hilty 2003).