November 8, 2012 | 8
A captive parrot in an Austrian research lab near Vienna has started using tools, adding to a complex story that began more than fifty years ago in the forests of Tanzania. “During three years in the Gombe Stream Chimpanzee Reserve in Tanganyika, East Africa, I saw chimpanzees use natural objects as tools on many occasions,” Jane Goodall wrote in a paper published in the journal Nature. “These objects consisted of sticks, stalks, stems and twigs, which were used mainly in connexion with eating insects, and leaves which were used as ‘drinking tools’ and for wiping various parts of the body.” It is said that when Louis Leakey, another famous primatologist and Goodall’s supervisor, received an excited telegram from her describing her discovery, he responded, “Now we must redefine tool, redefine Man, or accept chimpanzees as humans.”
Since the early 1960s when Goodall first went to Gombe, membership in the club of tool users expanded from uniquely human, to humans and chimpanzees, and now includes elephants, dolphins, octopuses, crows, ravens, rooks, jays, dingoes, and dogs (sort of). Among birds, tool use is now well-documented in corvids (crows, rooks, jays, ravens), but evidence is scant for tool use in other bird families.
Now, a parrot named Figaro may pave the way for admission into the tool-use club for his species, the Goffin’s Cockatoo, also known as the Tanimbar Corella or Goffin’s Corella (Cacatua goffiniana). Figaro is part of a captive colony of cockatoos in the Department of Cognitive Biology at the University of Vienna. One day, the male parrot dropped a pebble through an opening in the wire mesh surrounding the aviary in which he was housed, where it fell onto a wooden beam. Figaro tried in vain to retrieve the pebble with his claw. Frustrated, he flew away, retrieved a small piece of bamboo, and holding it in his beak, tried to use it to nudge the pebble back into his enclosure. He was unsuccessful. Still, no Goffin’s cockatoo in the wild has ever been recorded using a tool, so the behavior was remarkable.
But was it a fluke? Luckily, a student observer noticed the exciting behavior and reported it to the researchers, who immediately moved Figaro to a new enclosure. If Figaro had spontaneously learned how to use tools, they did not want the other parrots who had been housed with him to acquire the skills through social learning (not yet, at least). Into the new enclosure went Figaro and a female named Heidi, so that Figaro would not develop stress in social isolation.
In ten different trials over the course of three days, the researchers placed small cashews on the wooden beam outside the aviary, just as the pebble was in the initial observation. In the first test, Figaro started by trying a stick that had been lying on the floor of the enclosure, but it was too short. He then broke a splinter off of a wood beam and, holding it in his beak, successfully retrieved the nut. In all, it took him twenty-five minutes to get his snack. Not only was he able to use a pre-existing tool, but he spontaneously manufactured it!
In the second through tenth trials, his performance was significantly faster. He spent at most five minutes, and two and a half minutes on average, manufacturing his tools. The tools were removed from the aviary after each trial, so that he wouldn’t be able to keep using the same tool to accomplish the task. Tools two through five were, like tool one, fashioned by splintering wood off of larger beams. Tool six was made the same way, but was too long. After one attempt with the longer stick, Figaro broke it in half, and then used it effectively. Tools seven and eight were also splinters. Tool nine was a piece of bamboo from the floor of the enclosure that did not have to be modified. The tenth tool was a twig from the floor of the aviary that Figaro cut four times before he deemed it suitable. Ten times in a row, Figaro successfully found or fabricated tools to retrieve a cashew!
Pipin, another male from the cockatoo colony, was tested in the same situation and never displayed any sign of tool use or modification. Heidi, however, showed a bit more promise. Like Figaro, she broke splinters off of the wood beam and inserted them through the mesh to try to manipulate the nuts, but she was never successful. It is unclear whether she learned the tool manufacture method by watching Figaro, or came to the solution independently. The researchers compare Figaro’s tool manufacture to that of another tool-using bird, a blue jay that ripped pieces of newspaper to rake food pellets.
What makes this particularly exciting, though, is that Figaro is a parrot, not a corvid. It is unlikely that they share a tool-wielding ancestor, as the two groups of birds diverged more than 91 million years ago. Corvids are nest builders and have straight beaks. These birds routinely modify twigs and sticks for use in nest building using their beaks, so the cognitive leap to tool manufacture makes anatomical and ecological sense. Parrots, however, nest in naturally occurring cavities found in trees and have curved beaks, something that makes it especially hard to effectively manipulate a stick (Figaro did it by pressing the stick against his upper beak with his tongue). The researchers say that this makes Figaro’s performance “difficult to explain in terms of recombination of conventionally acquired, previously reinforced behaviors.” It means that tool use can spontaneously develop in an individual whose intelligence had not been explicitly shaped by evolution for tool use.
As vocal-learning songbirds, parrots have long been studied for insights into language, but now it seems as if the ability to use tools for solving problems exists within their cognitive toolkits as well, at least under certain conditions. Identifying just what those conditions are now falls to the researchers, who also plan to see how different experiences throughout a cockatoo’s development could contribute to tool-related abilities, as well as the extent to which tool use could spread to other cockatoos through social learning.
Auersperg A.M.I., Szabo B., von Bayern A.M.P. & Kacelnik A. (2012). Spontaneous innovation in tool manufacture and use in a Goffin’s cockatoo, Current Biology, 22 (21) R903-R904. DOI: 10.1016/j.cub.2012.09.002
For more on tool use:
For Chimps, Tool Choice Is A Weighty Matter
Dogs, But Not Wolves, Use Humans As Tools
Dingoes Ate My Nametag: Tool Use in a Dingo
Chimpanzees Help, But Only When Asked
How Do You Figure Out How Chimps Learn? Peanuts.
Header and footer photos by Alice Auersperg. Tools image modified from Auersperg et al., (2012) Current Biology.