Next time you call someone a bird brain, think twice. UC Santa Barbara's Corina Logan conducted a new research with her collaborators at the University of Auckland in New Zeland. This research was supported by the National Geographic Society/Waitt Grants Program.
The results showed that birds possess a high intellectual dexterity than known before. The study aimed at discovering the casual cognition of the bird with the use of a water displacement paradigm. Junior research fellow at UCSB's SAGE Center for the Study of the Mind and lead author Logan said that the study discovered and demonstrated the crows' ability to differentiate between varying volumes of water, a test that 7 to 10 year olds passed successfully. She said, "We provide the strongest evidence so far that the birds attend to cause-and-effect relationships by choosing options that displace more water."
She worked with New Caledonian crows in a set of small aviaries in New Caledonia run by the University of Auckland. She explained that wild crows were brought to the aviaries where they were habituated for five days. Since testing individual birds was quite a task since they would fly away, four of them were kept in the bird houses.
They were trained extremely well; Logan could open the aviary and point at a bird signaling it to fly out, "while the other birds stayed put." After training them and coming so far with the birds she went to the next level of the experiment. The birds were given two beakers of water placed in an apparatus; they were of the same height but differing widths- one narrow and the other wider. The diameters of the lids were made the same on each beaker."The question is, can they distinguish between water volumes?" Logan said. "Do they understand that dropping a stone into a narrow tube will raise the water level more?"
They were given four objects which had to be dropped in the narrower one for a raise in the water, the wider one would not prove beneficial and the birds would not be able to drink from them. "They were dropping all or most of the objects into the functional tube and getting the food reward. It wasn't just that they preferred this tube, they appeared to know it was more functional," said Logan
However, she said that it was still unclear as to how crows could process the information required to solve the task. There was more work needed to be done to understand their cognitive workings she said.
Logan also evaluated the crows reaction to the U-tube task, where two set of tubes are provided. When the subject drops the tone into the wide tube in one set, the water level rises in an adjacent narrow tube whereas in the other set it does not. There is a hidden connection between the tubes of one set and no connection in the other. The tubes were of different colours red and blue. There is no logical reasoning to the rise of the water for the subject, except that one coloured tube would cause a raise in the levels while dropping the stone in the other would not cause any effect. It was seen that 7 to 10 year olds could perform the task and identify the functional tubes on the basis of the colours but the birds failed.
Logan and her team modified the apparatus and increased the distance between the beakers, and Kitty a, a six-month-old crow passed the test. Logan could not understand how the bird could figure the test out, she said, "We don't know if the same cognitive processes or decisions are happening as with the children, but we now have evidence that they can. It's possible for the birds to pass it. What we do know is that one crow behaved like the older children, which allows us to explore how they solve this task in future experiments," she continued.
Until now, no smaller-brained species were tested with the tests they used on the crows, "And grackles are smaller-brained," she said. "But they're really innovative. So they may have a reason to pay attention to causal information like this."
The study is published in the scientific journal PLOS ONE.