A pair of gang gangs are regularly at this site, although the male is usually just sitting in the rim and not entering the hollow. On this occasion, four SCCs arrived and started investigating while the GGs were both on a branch nearby. The male repeatedly swooped the intruders and eventually drove them away, with help from a passing galah. The female just watched. This hollow has previously been the domain of galahs but I don't think they actually bred there.