A long-held view that koalas get all their hydration from eating leaves has been overturned by new research by a team at the University of Sydney.
The study—published in PLOS ONE—offers hope in the fight to conserve this threatened species, with researchers finding that koalas will regularly use artificial water stations, particularly during hot and dry conditions.
“Drinking stations could help koalas during heat and drought events and might help mitigate the effects of climate change,” said Dr Valentina Mella from the School of Life and Environmental Sciences.
Dr Vella added that drinking stations could also prove a useful strategy to support other arboreal folivores such as gliders and possums in Australia and sloths, lemurs and some monkeys on other continents.
Koala populations along Australia’s east coast have been declining due to lost habitat from deforestation, diseases such as chlamydia, attacks from feral animals, fire and vehicle collisions.
Koalas are also particularly vulnerable to the effects of climate change, suffering heat stress and because the trees they rely on are affected by temperature and rainfall change.
Koalas can’t simply eat more leaves to compensate for reduced water content in their favourite food. This is because koalas are limited in their food intake by leaf toxins.
“It is predicted that increased CO2 emissions will increase the level of phenolics and tannins in eucalyptus leaves,” Dr Mella said. “This means koalas will need alternative strategies to find water—and that’s where we can help with drinking stations.”
Dr Mella has been conducting field work in Gunnedah in western NSW where, in 2009, a heat wave killed an estimated quarter of Gunnedah’s koala population.
“We weren’t sure if the water stations could be used to mitigate the impact of extreme weather events,” she said. “But our results clearly show koalas will regularly use these stations to supplement their water needs.”
During the first 12 months of the study, Dr Mella and her team recorded 605 visits to 10 pairs of water stations, with 401 of these visits resulting in koalas drinking.
They found that the total number of visits and total time drinking doubled during summer compared to other seasons.