Adorable video of koalas reveals survival strategy that surprises researchers
Drinking water seems like a universal behavior all mammals need to do to survive, but until now, scientists thought koalas were a rare exception.
But for the first time ever, the fuzzy marsupials were caught drinking water dripping down tree branches and trunks during and immediately after rain fell over their homes, according to a study published Saturday in the journal Ethology.
The discovery — made with 13 years worth of observations — highlights the need to further study koalas’ drinking habits in a time when their homes in Australia are suffering the “longest dry period ever documented, with severe rainfall deficits and record maximum temperatures,” a press release on the study said.
“For a long time, we thought koalas didn’t need to drink much at all because they gained the majority of the water they need to survive in the gum leaves they feed on,” Dr. Valentina Mella, a postdoctoral research associate studying animal behavior and conservation at the University of Sydney, said in the release. “This significantly alters our understanding of how koalas gain water in the wild. It is very exciting.”
In the past, koalas have been observed drinking from waterholes in the summer when temperatures were high, as well as occasionally going up to humans, gardens and swimming pools to hydrate during droughts and after fires due to heat stress, the release said.
But these are considered rare occurrences, the researchers said. Scientists always thought the animals received their needed water intake from the 510 grams, or about one pound, of eucalyptus leaves they eat each day.
Experts believed that was all they needed because they also have “extraordinary urinary concentrating abilities” and don’t lose water from their skin as much as other similar-sized mammals, according to the release.
Koalas are also active at night, and sleep during the day.
“As koalas are nocturnal animals and observation of their behaviour rarely occurs during heavy rainfall, it is likely that their drinking behaviour has gone largely unnoticed and has therefore been underestimated in the past,” Mella said in the release. “Our observations probably only represent a minority of the drinking that normally takes place in trees during rainfall.”
Scientists learned of their drinking behaviors by studying 46 videos and photos of wild koalas licking water from trees between 2006 and 2019 at the You Yangs Regional Park in Victoria, Australia and the Liverpool Plains in New South Wales.
The videos were taken by citizen scientists, or amateur researchers, and independent ecologists, the study said.
The animals were also observed licking water from trees even when other sources of standing water were available, like in dams, the study said. One of the observations showed an adult male koala that drank for 34 minutes straight.
The researchers want their results to offer insight into whether water should be provided for some populations during certain times of the year, especially after the recent Australian wildfires that left koalas burned and begging humans for water.
The research also sheds light on the need for conservation.
“We know koalas use trees for all their main needs, including feeding, sheltering and resting,” the release said. “This study shows that koalas rely on trees also to access free water and highlights the importance of retaining trees for the conservation of the species.”
