Fears are held for remaining populations of the Glossy Black Cockatoo and the Kangaroo Island Dunnart as a scrub fire burns through key habitat for the two endangered species.
The Country Fire Service says it is liaising closely with ecologists on how to control the spread of the Kangaroo Island blaze to protect as much of the habitat as possible.
Large areas that were home to the two animals were destroyed in last summer's devastating fires which raged through more than 200,000 hectares on KI's west.
The Western River fire started on Tuesday afternoon and is burning in an area around De Mole River about 40km west of Parndana.
It has burnt through more than 260 hectares but poses little threat to lives and property with a bushfire warning in place for local residents.
"Whilst the fire is expected to burn for a number of days, crews have been working hard today in very challenging terrain to halt the forward rate of spread," the CFS said.
"Crews have managed to successfully complete back burns on the south and western flanks of the fire and are currently in the process of completing a backburn on the eastern flank."
No roads have been closed but motorists have been urged to avoid the area unless absolutely necessary.
The CFS will continue to monitor the fire overnight and further resources will be in position on Thursday ahead of the erratic winds.
Rain is also forecast across the island with falls of up to 20mm possible.
