My mother used to say that when my younger brother had jobs to do he wouldn’t be within coo-ee. It is a very Australian expression meaning that he wasn’t within calling range.
When Australians are in the bush and they want to attract attention or discover if there is someone nearby, they used to call out “COO-EE” in a high pitch. If they got a reply, then someone was on the way.
Australia is a big, big place (see Safe and Easy and SO Worth It page). Come and explore it and you might just call “Coo-ee” sometime. OR you might like NOT being within coo-ee!