After four months of nest box monitoring and some seemingly disappointing early results, the Queensland Glider Network is celebrating the recent occupancy of a nest box in Brisbane’s north by a greater glider.
The QGN greater glider nest box project has been in full operation since December 2017. Teams have been monitoring the boxes on a monthly basis to try and understand the uptake of nest boxes by greater gliders and non-target species. To date, more than 126 hours of volunteer time has been utilised for the monitoring. However, the usage of nest boxes by animal species has been less than enthusiastic. Of the 44 boxes installed across the three study sites, so far only three boxes have been occupied.
But on 17 March, volunteers including members of Wildlife Queensland’s Moreton Bay Branch were fortunate enough to experience what we’d all been waiting for – a greater glider occupying a nest box in a bushland reserve on Brisbane’s north side; evidence that the species is capable of using the boxes if required.
When reporting on the outcomes of our projects we look forward to telling our supporters just how successful an operation has been, and normally this reporting is all about numbers. This reflects how we judge the value of the project internally at Wildlife Queensland too, in some way. So it stands to reason that our current greater glider project feels like we are not kicking goals. But it’s worth thinking about the results of this project not in terms of the number of animals living in boxes, but rather in terms of the information to be learnt from a lack of occupation.
So what can we begin to take away from this project at the four-month stage? And what additional questions has the project generated? Well, importantly, greater gliders will use a nest box; we now have proof such as that pictured. If we learn nothing further, this alone is very important feedback. This information suggests that if push comes to shove, we can provide artificial nesting resources for this vulnerable species where a lack of natural hollows is limiting the resident population.
Another possible learning from this project still in its infancy, and one that may be considered a ‘no-brainer’, is that greater gliders prefer natural tree hollows to nest boxes. We have installed our boxes in stable populations of greater gliders, in bushland reserves that have natural tree hollows. There may not be a need for the species to occupy the artificial hollow while natural hollows are easily available.
And there is nothing wrong with giving our greater gliders a preference. Gibbons and Lindenmayer (2003) comment on a number of factors that influence the likelihood of a hollow’s suitability. These include hollow characteristics (opening and internal dimensions), the number of hollows in the particular tree, tree health, tree diameter, tree location and tree spacing. It is highly conceivable that our tree choices for nest box installation have not all been suitable. In Gibbons and Lindenmayer (2003), Kehl and Borsboom (1984) were noted to have found that seven of nine primary den trees used by greater gliders had multiple tree hollows. We chose to install our boxes on trees that did not have any natural tree hollows and this is something we may investigate in future projects.
The QGN is genuinely looking forward to watching this project progress over the coming months. We are learning that ‘no result’ is in fact an important result and this is forcing a positive shift in the way we think about the outcomes of other projects going forward.
Gibbons, P. & Lindenmayer, D. (2003). Tree Hollows and Wildlife Conservation in Australia. CISRO Publishing Australia