They were fitted with radio transmitters to track their movement in their new environment.

The devils have been fitted with radio collars and there are cameras covering the sanctuary for monitoring.

To keep track of this revenue, vehicles were fitted with radio tags to pinpoint their position to within half a metre.

The pair had been fitted with radio transmitters by conservationists and had wintered in the area the previous two years, MacKenzie said.

Explaining how the system works, Savadia said the vehicle of a subscriber would be fitted with radio-frequency identification (RFID) sticker on the screen.