Re male koala grunting at night

Hi All,
re Sue Dawson’s email on a ‘male koala grunting at night’. Last year I was pleased that a koala had moved into to the Rise and Shine bush reserve next to my place in central Victoria. He grunted at night in the forest but I was never able to sight him. Same again this year. There are however dozens of Straw-necked Ibis that roost in the forest at this time of the year and their deep grunting is pretty similar to a koala’s. Has anyone else experienced this?
regards
David

PS My first Painted Honeyeater at Rise and Shine calling and sighted over the past couple of days