Giant pandas eat plenty of vegetables, but apparently they like dessert, too.
Scientists studying the endangered black-and-white bears said on Thursday that while pandas almost exclusively eat bamboo, which contains only tiny amounts of sugars, they showed a strong preference for natural sweeteners in an experiment.
The researchers also examined panda DNA and found a match to the same "sweet receptor" gene that humans possess that underpins their ability to taste sugars.
Sweeter foods like fruit may have been part of the natural diet of pandas before human activities helped drive the animals into their current mountainous habitat where those foods are scarce, the researchers said.
"Giant pandas love sweets," said behavioural geneticist author Danielle Reed of the Monell Chemical Senses Centre in Philadelphia, who led the study published in the journal PLOS ONE.
Pandas inhabit bamboo forests high in the mountains of western China. Understanding what type of food they prefer may help determine what nutrients can be used to supplement bamboo in their diet as part of efforts to conserve them, the researchers said.
The experiments involved eight giant pandas at the Shaanxi Wild Animal Rescue and Research Centre.
The bears were given two bowls of liquid and permitted to drink for five minutes. One was filled with plain water. The other contained water mixed with one of six natural sugars. The pandas liked all the sugar solutions better than plain water, especially fructose and sucrose.
The researchers then did the same tests with five artificial sweeteners, but the pandas were far less interested in those.
"Giant pandas' ancient diet may have included more foods than just bamboo ... It may be that bamboo is an everyday food for giant pandas, but when sweeter foods are available they go for them," Reed added.