Water Turnover on St Bees
with Dr Bill Ellis
Koalas survive in some very dry areas in Queensland, without access to
much free water. During Alistair Melzer's research work at Springsure,
we analysed koalas' water turnover during summer and winter to see how
much water they used and whether they drank water when it was available.
When it is hot and dry, koalas use evaporative water loss (mostly through the lungs) to cool down, so they eat a lot of high moisture leaves. In winter, they burn a lot of energy to keep warm, but the water content of their food is less important.
The conditions on St Bees Island are quite different to those in central Queensland. The relative drought in which the central Queensland koalas exist is replaced by a hot wet climate, which presents a totally different set of factors for the koalas to deal with.
During the July field trip to St Bees we started investigating the water turnover of the koalas, using a stable isotope called Duterium. The work was designed to establish whether koalas at St Bees have a significantly different rate of water turnover to their more arid-dwelling counterparts.
This work will allow us to investigate their energy requirements and
better understand the way they use their unique habitat on the island.