Cockatoos like to dunk their biscuits before eating, according to a pair of researchers from the University of Vienna, Austria.
The researchers observed captive Goffin’s cockatoos regularly dunking dry biscuits called rusks in water.
They’ve published their observations in Biology Letters.
Goffin’s cockatoos (Cacatua goffiniana) are native to Indonesia. While plenty of other animals have been observed dunking their food in liquid before, this is the first time scientists have reported the behaviour in parrots.
The researchers first spotted cockatoos dunking rusks, which they received in their daily feed, into their water before eating at the Goffin Lab in Austria. They decided to follow up with a formal study, watching 18 birds at the lab for 15 minutes each day, right after they received their daily feed.
Over 12 days, they observed 7 of the 18 birds regularly dunking their food, usually the rusk but occasionally other pieces of feed.
The birds left their rusks in the water for an average of 23 seconds, long enough to soak them through according to separate tests done by the researchers.
“Our focal birds ate rusk almost exclusively after dunking it,” write the researchers in their paper.
According to the researchers, there are five broadly accepted reasons for why animals might dunk their food: softening hard foods, washing off dirt, improving flavour, drowning live prey, and transporting liquid (like a sponge).
In this study, they think it’s most likely the birds are dunking to soften hard foods, given their preference for dunking rusk.
“This dunking behaviour requires several components of primordial forms of planning such as impulse control and temporal discounting to actively produce a qualitative benefit,” write the researchers in their paper.
“It also once more reflects the innovativeness of this parrot species, now also in a food preparation context.”
