Goffin's Cockatoos Able to Use Tool Set to Access Their Snacks
Michelle Milliken
When we've got a snack we enjoy, we'd really like to dig in. Sometimes the packaging can be a pain, though, and we have to reach for scissors, a knife, or some other tool to get it open. Goffin's cockatoos can relate. In a recent study, they were able to identify, transport, and use two tools needed to reach a favorite treat, suggesting that they have a firm grasp of the use and need of tool sets for certain tasks.
Researchers from University of Veterinary Medicine Vienna recently investigated how captive Goffin's cockatoos used available tools when they were cut off from a piece of a nut. This was based off of research showing that chimpanzees were able to use two different tools to access termites: one to open termite mounds and one to probe for termites afterward. They also bring both over for the task. The researchers say that while prior studies have shown Goffin's cockatoos can use tool sets - making them the only non-human animal other than chimpanzees to do so - there was no clear evidence that they could mentally represent the tool set and understand that they went together.
Antonio Osuna-Mascaró, from the Messerli Research Institute at the University of Veterinary Medicine and the study's lead author, explains, "So, we presented to them a problem that resembles what is required for chimpanzee termite fishing: a membrane blocking access to a piece of nut, and two tools, a short pointy stick and a long flexible one. The membrane could only be ripped by using the pointy tool, but this was too short to reach the reward, so they would need to use both in sequence.”
Several of the birds mastered this task quite quickly, with a male named Figaro doing so in 31 seconds and a female named Fini managing it in 34 seconds. Others needed a few more tries, but they still managed it.
Next, to test the birds' flexibility in using the two tools, the team alternated between situations in which there was no membrane blocking off the nut and one where there was. Sometimes, the whole tool set was needed and sometimes only one tool was necessary. This required the cockatoos to address the problem at hand.
This task was mastered by the birds, too, but there was a little hesitation at first.
Alice Auersperg, co-author and head of the Goffin Lab, says, "Before inserting the first tool, the animals tended to switch back and forth between picking up the two different options. Interestingly, their performance improved after performing this switching action; the probability of selecting the correct tool was higher after repetitive switches."
There was one other aspect the team tested: whether or not the birds would transport the tool set together, showing that they grasped that they were needed together. To determine this, the researchers placed either a box with the membrane or a box without it on a platform. To access the platform, the cockatoos first needed to climb a ladder. After that they could only reach it via flight, first a short horizontal one and then a tougher vertical one.
The team found that four of the cockatoos eventually transported the tools together to the platform, even when flight was required. After learning how to transport them, three birds in particular did so consistently every time they encountered a box that called for them and less frequently when they weren't needed.
Osuna-Mascaró says, "Our cockatoos, did always have the opportunity to go back and forth, using one tool and then go back to pick up, transport and use the other. Instead, at least three of them learned to collect both tools in advance. This suggests that they can categorize both tools as a set."
The team says the findings help provide a better understanding of how our own abilities came to be. The researchers also hope to conduct future experiments to learn more about the birds' decision-making process and metacognition.
This study was published in the journal Current Biology and can be read in full here.
