Redland koala populations have crashed by 80 per cent from 1996 to 2014 and may be in terminal decline, according to a report for the Queensland environment department.

Heavy development is thought to be behind the crash, as well as disease, dog attacks and car strikes, with the report showing protection measures have failed to curb the decline, the Redland City Bulletin reports.

The dead koala on the road side at Redland Bay Road.

The University of Queensland study by Associate Professor Jonathan Rhodes, Dr Hawthorne Beyer, Dr Harriet Preece and Professor Clive McAlpine says the declines are rapid and likely increasing in the area east of Brisbane.

The difference between the Pine Rivers and Redland is likely due to the latter – a koala stronghold 20 years ago – having been more heavily developed.