Common Koels are migratory. When they arrive in eastern and northern Australia, usually in late September or early October, the loud repeated territorial calls of the males are a sign to many of us that summer is coming. They are not everyone's favourite bird. Unless you are a sound sleeper, having a Koel just outside calling coo-weee for half the night is disturbing to say the least. Sample LS100113 is our local male at Mt Coochin in Queensland advertising has territory with coo-weee calls. Notice how the pitch of each call rises and as the session progresses he appears to sound more and more frantic. LS100203 is the same bird, this time calling wurra-wurra wurra. The function of this call is not clear - often a male precedes a session of cooeeing with a few of these calls and it is the main call he uses when calling together with his female. Samples 177-620 from Jervis Bay and 021-110 from Mossman in Sydney include both male and female calling - the female call is the distinctive high pitched "keek-keek-keek". You can actually hear two females calling at the beginning of sample 021-110, a sort of confrontation or that's what it sounds like. The male occasionally gives another call, a loud "wheck" which I've picked out of one of the confrontations and loaded it in sample 177-650 - it also includes a couple of notes from the female, but the last two notes are by the male.