Sept. 7 (UPI) -- If you give an Australian magpie a donut and a cup of coffee, he or she will be likely to dunk it. The magpie is a dunker.
New researchers suggest magpie offspring learn to dunk their food in water before eating by copying their parents.
Food-dunking isn't unusual. The behavior has been observed in 25 bird species -- the Australian magpie is only the latest to be seen dunking before eating.
Researchers haven't been able to figure out exactly why some species deploy the technique and others don't. Some have suggested birds dunk toxic insects in water to minimize their bitter taste.
Biologists from the University of York tested their hypothesis in the wild.
"We presented the wild magpie with a local insect called mountain katydid, which is thought to be distasteful due to the toxins it emits," doctoral student Eleanor Drinkwater said in a news release. "The adult magpie first dragged and beat the insect on the ground before carrying it to a nearby puddle, dunking it and thrashing under water."
After eating the insect, the adult returned to the puddle for a second insect. After dunking, the magpie left the dunked katydid behind. A juvenile retrieved the insect and mimicked the dunking action.
"Although more research is needed to understand why the bird dunks its food before eating, our initial assumptions are that it responds to the 'nasty tasting' chemical defenses of the insect, by dunking it in water and making it more palatable," Drinkwater said.
The findings -- detailed this week in the journal Australian Field Ornithology -- also suggest birds learn dunking by mimicry.
"It was exciting to see that this process was copied by the juvenile bird, suggesting that this behavior could be socially learnt," Drinkwater said. "More research can now be done to determine how common this behaviour is from adult birds through to its offspring."