Tool making is a complex behavior that, until recently, had only been confirmed in three species of primates (including humans), and in some birds, including captive Goffin's cockatoos. Now, a research group at the University of Vienna that has studied Goffin's cockatoos for decades has also observed the behavior in wild cockatoos.
This species of cockatoo, a member of the parrot family, is comparable to three-year-old humans in terms of intelligence. But before now, tool making behavior has not been observed in wild cockatoos, which is necessary to confirm that a species is indeed capable of making tools and their tool use is not just an artifact of captivity.
The group spent over 884 hours observing wild birds in their natural habitat in the Tanimbar Islands, Indonesia, with no success in witnessing tool use and manufacture. They then moved on to a catch and release method, where they captured 15 individuals and placed them in temporary aviaries with many resources and a food option that finally encouraged more complex approaches to foraging: the Wawai fruit, or sea mango. The cockatoos really like eating the seeds of these fruits and need to go through the thick skin and flesh of the fruit in order to reach the seeds.
Two of the 15 individuals manufactured and used tools to extract sea mango seeds. Those two birds made tools by removing fragments from branches and then modifying them with their beaks. The researchers identified three different tool types: wedges, to widen the fissures to reach the seed inside the fruit; fine tools used for piercing the coating of the seed; and medium tools used for scooping the seeds. Furthermore, the tools were used sequentially, which the researchers believe to be the most complex example of tool use in a species without hands.
Both cockatoos proficiently manufactured and used the tools immediately after provided the Wawai fruit, suggesting they knew how to do that before capture. The fact that only two individuals were observed using tools indicates that this complex skill is not found species-wide and therefore has to be learned as a result of opportunity and innovation. This finding broadens our understanding of tool making ability beyond just primates.