In spring, people may notice an extra bird voice added to the usual chorus. A distinctive repeated koo-el is the call of a male Eastern Koel (Eudynamys orientalis). The call is used to demonstrate territory and attract a mate. In Brisbane the name of the suburb of Toowong was derived from the Turrbal word for Koel, which was also an imitation of its call. Although the Koel is a diurnal bird, it can sometimes call at night.