- The number of flying-foxes roosting in a camp is estimated by counting the animals as they fly out at night to forage for food.
- Fly-out usually commences about 20 minutes after sunset, although weather conditions can cause variations.
- A mechanical (click) counter is used to record the number of flying-foxes, ten at a time, passing the recorder’s field of vision.
- By combining the number counted at each flight path an estimate of total numbers of flying-foxes in the camp can be recorded.
The monthly ‘counts’ conducted by volunteers at Ku-ring-gai Flying-Fox Reserve, Gordon, contribute to our understanding of the whole grey-headed flying-fox population in eastern Australia. (Read more about movement of flying-foxes.)