Posted on 7 September 2017
The research could potentially shed more light on the dietary systems of some bird species and how they respond to the defences of its prey.
Food dunking is common behaviour in a range of bird species, but has never been observed in the Australian Magpie before. Not only was it observed in the adult bird, but the offspring were seen to copy the ‘dunking’ process.
Dunking is thought to be an important food-process for birds, but it remains unclear as to why some birds do this and some do not. One theory is that it helps moisten the food to make it more digestible and other theories suggest that it might help make unpalatable insects less toxic to eat.
Eleanor Drinkwater, PhD student at the University of York’s Department of Biology, said: “Food dunking has been seen in at least 25 bird species, particularly in birds that have high cognitive abilities.
“The Australian Magpie is an intelligent animal, however we were not expecting to see dunking displayed by this bird. In a separate study on predator-prey interactions between katydids and Australian Magpies we were observing a family of magpie at a site near Kosciuszko National Park to see what they would do when offered the insect.
“We presented the wild magpie with a local insect called Mountain Katydid, which is thought to be distasteful due to the toxins it emits. 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.”
Socially learnt behaviour
The adult male bird appeared to eat the insect under a nearby bush, before returning to take a second insect, repeating the action, but this time leaving the ‘dunked’ insect at the side of the puddle.
The team then observed a juvenile bird that had been watching the adult male pick up the discarded insect and mimic the actions of the adult male before eating the insect whole.
Eleanor continued: “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 defences of the insect, by dunking it in water and making it more palatable.
“It was exciting to see that this process was copied by the juvenile bird, suggesting that this behaviour could be socially learnt. More research can now be done to determine how common this behaviour is from adult birds through to its offspring.”
The research is published in the journal Australian Field Ornithology.