In late January /early February we start taking the pups out to the release cage. We like them to weigh a minimum of 450 gms and have a forearm of at least 145mm. We initially used a large dog crate winched up into the canopy as we were worried about the security of the site. But after many years with no problems and increasing numbers to release we built a ground cage. Orphans are taken out to the release cage in groups of 20-30 and kept inside the cage for 3-7 days depending on a number of factors eg weather. It’s long enough to get used to the different sounds and smells, as well as the presence of the wild bats. We release each group in the morning, and then bring another group out that afternoon. We believe the presence of the orphans inside the cage encourages the outside orphans to return – as well as the presence of food. It is vital they integrate into the social structure of the colony, which at that age means being with the wild pups at night (wild pups are with their mother still in the day, until weaned), flying out and learning with them about bush tucker and gaining the strength/endurance for long-distance flight. The pups generally stay with their peers until their third year when they integrate fully into the adult life of the camp.
Proximity to a reliable flying fox camp is very important. Tolga is occupied all year round most years and our release cage is in the forest within 0 to 100 metres of the wild bats. The last group of bats is taken out in April so that there is at least a month before the wild numbers of bats usually dwindle over winter. The last group of orphans is the smallest and most vulnerable group. We lower our ideal size of orphan at this stage to a minimum of 140mm forearm. It means that every year we need to hold over a few that were born very late in the season.
Daily feeding is continued for at least a month after the last orphans are put outside. The food is then reduced. They are fed less frequently as well as a lesser amount. Often in June we will still go out once a week and have 30 or so bats come down to the cage. The success of the release is evident by the numbers of orphans from previous years returning to the cage, as well as some microchip returns.
Read about our release cage in our Facilities section.
Photo: (above) We scanned pups returning to the cage for support feeding for the first few years. This showed that 90% returned at least once. We had a pup released in 2001 who was found on a search in 2002 with tick paralysis. She had only been recorded once at the cage, yet had survived 9 months in the wild. She recovered from the paralysis to be released again.
Watch the pups flying /climbing to the release for support feeding.
Watch the pups feeding at the release cage.