Koalas eat only the leaves of eucalyptus trees, and most of their water comes from moisture in the leaves. So you could say that koalas eat and drink eucalyptus.
But there is another source of water that koalas drink from. Rain.
Eating in the rain gives koalas food and a big drink, at the same time. In summer, when rainfall has been scarce, koalas are thirsty. In fact, new science is showing that koalas are thirsty even in winter.
As soon as rain starts to fall in the You Yangs, most koalas wake up and start eating. We have noticed that we are much more likely to record koalas feeding on days when it is raining.
Climate change is drying out our forests in some areas, and bringing heavy rainfall at odd times to other areas. The You Yangs, where koala Bunyip lives is in a part of Australia that is predicted to get drier in winter (-25% by 2090) & spring (-45%) . There may be changes to summer & autumn rainfall, but those are not clear. Temperatures are expected to rise in all seasons. Droughts are expected to increase.
Already, the forests of the You Yangs are noticeably drier and more open than they were 20 – 30 years ago. Wetlands that were permanent in the 1990s are now ephemeral, and only hold water after significant rainfall.
Koalas may have once survived on just the moisture in leaves, but their situation is different now.
Contact a politician this week, and tell them you want action on climate change for the sake of our koalas. List of relevant Australian politicians
This excellent website gives information on local climate predictions: https://www.climatechangeinaustralia.gov.au/en/climate-projections/future-climate/regional-climate-change-explorer/super-clusters/
NOTES & REFERENCES:
Mella, Valentina S. A., et al. “Needing a drink: Rainfall and temperature drive the use of free water by a threatened arboreal folivore.” PLoS ONE, vol. 14, no. 5, 2019, p. e0216964. Gale OneFile: Health and Medicine, https://journals.plos.org/plosone/article/file?type=printable&id=10.1371/journal.pone.0216964