Bruce, a parrot missing part of his beak （喙）, creatively uses stones to clean feathers （羽毛）, highlighting advanced intelligence in parrots.
Bruce lost the upper part of his beak in 2012 and was sent to live at a reserve in New Zealand. The defect made Bruce unable to search for food on his own, let alone keep his feathers clean with his beak. But in 2021, when comparative psychologist Bastos arrived at the reserve with colleagues to study parrots, zookeepers reported something strange：Bruce had seemingly figured out how to select and use small stones to clean his own feathers with his beak.
Over nine days, the team kept a close eye on Bruce, quickly taking, videos if he started cleaning his feathers. It turned out that Bruce had indeed invented his own way to do so, the researchers reported in Scientific Reports.
"It's crazy because the behavior was not from the wild, " Bastos says. When Bruce arrived at the reserve, he was too young to learn how to clean his feathers. And no other bird in the reserve uses stones in this way. "It seems like he just invented this tool use for himself, " she says.
Tool use is just one of parrots' many talents. They're famous for copying and even understanding human speech. Some species can also solve complex puzzles, like how to enter a covered rubbish bin or practice self-control.
For a concept as abstract （抽象的） as intelligence, it's challenging to develop a definition that applies across animals. Researchers often point to features once thought to make humans special—enhanced learning, memory, attention and movement control—as signs of advanced skills. However, many of these abilities can also be seen in parrots, as well as other animals like chimpanzees, dolphins and elephants.
"Parrots are our evolutionary （进化的） mirror image. These brilliant birds may teach us about how humanlike intelligence can appear, " behavioral ecologist Antone wrote in his 2022 book The Parrot in the Mirror. With powerful brains and a preference for words, these birds are "the very best example, " he writes, "of nature's 'other try' at humanlike intelligence. "