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
Christianity in Australia Christmas in Australia is celebrated during the Southern Hemisphere summer, many Northern Hemisphere traditions are observed in Australia – families and friends exchange Christmas cards and gifts and gather for Christmas dinners; sing songs about snow and sleighbells; decorate Christmas trees; and tell stories of Santa Claus. Nevertheless, local adaptations have arisen – large open-air carol concerts are conducted on summer evenings before Christmas – such as the Carols by Candlelight in Melbourne and Sydney's Carols in the Domain. The Christmas song "Six White Boomers", by Rolf Harris, tells of Santa undertaking his flight around Australia hauled by six white-boomer