To better understand the use of nest boxes by Leadbeater’s Possum, in 1998 Professor David Lindenmayer and the research team set up a large nest box study in the Mountain Ash forests of Victoria’s Central Highlands.  We used a box design that had been successful with Leadbeater’s on the floodplain at Yellingbo and installed 96 boxes in total. The experimental design was guided by statisticians, as well as our and other’s expert knowledge of Leadbeater’s ecology.

Study methods:

-         Two different regions (Toolangi and Powelltown areas)

-         Two forest age classes (20 years post-logging regrowth and 60 years post fire and salvage logging reqrowth)

-         Two nestbox designs (large with large entrance holes and small with small entrance holes)

-         Two heights (3m and 8m above the ground)

-         Four boxes were set out at each of 24 sites

-         Adjacent to known records of Leadbeater’s Possum

Nestbox construction, site selection and nestbox installation drew a considerable amount of expense and labour. Following set up, the experiment ran for 10 years and the monitoring took researchers two weeks annually to complete. Large amounts of maintenance of the boxes was required as bees/ants colonised boxes and falling tree limbs caused damage or detachment. Despite these efforts, we calculated the life span of each nest box in the Mountain Ash to be less than 5 years.

After several years of monitoring, maintenance and repair, just 14 % of the 96 boxes showed signs of use by Leadbeater’s Possum, and this use represented just two possum colonies.  They were predominantly in younger regrowth stands, not older 1939 aged sites. A large proportion of nest boxes (68.8%) were never used by vertebrate fauna.

Mason Crane checks a nestbox with an inspection camera in the Victorian Central Highlands.

Suggested further reading:

Lindenmayer, D.B., Welsh, A., Donnelly, C., Crane, M., Michael, D., Macgregor, C., McBurney, L., Montague-Drake, R. and Gibbons, P., 2009. Are nest boxes a viable alternative source of cavities for hollow-dependent animals? Long-term monitoring of nest box occupancy, pest use and attrition. Biological Conservation142(1), pp.33-42.

Lindenmayer, D. B., MacGregor, C. I., Cunningham, R. B., Incoll, R. D., Crane, M., Rawlins, D., & Michael, D. R. (2003). The use of nest boxes by arboreal marsupials in the forests of the Central Highlands of Victoria.Wildlife Research30(3), 259-264.

Lindenmayer, D. B., Tanton, M. T., & Cunningham, R. B. (1991). A critique of the use of nest boxes for the conservation of Leadbeater's possum, Gymnobelideus leadbeateri McCoy. Wildlife Research18(5), 619-623.

Harley, D. K. (2006). A role for nest boxes in the conservation of Leadbeater's possum (Gymnobelideus leadbeateri). Wildlife Research33(5), 385-395.