Guardian environment reporter Graham Readfearn heads out in search of the elusive platypus.
Researchers tracking the DNA of the egg-laying mammals believe platypuses have likely gone from Kedron Brook and four other greater Brisbane waterways: the Bremer River, Scrubby Creek, Slacks Creek and Enoggera Creek.
They believe the threats to the animals' habitat are so severe that the Australian government should list the platypus as a vulnerable species