It is well-documented that some birds can build tools, but it was never really sure if this information was ever passed down to birds or if it was acquired in a different way.
What Was Discovered About Crows?
A study revealed that New Caledonian crows have the mental capabilities to make tools and to pass down this knowledge for future generations of crows. In the past, some scientists believed that crows could only imitate this, instead of learning it.
The study was published in the journal Scientific Reports on June 28.
These crows can twist twigs into hooks just by using their own memories. Their ability to engineer tools is a trait that clever birds use over the course of many years.
Crows, in general, were always considered to be smart. They can remember human faces and they can hide their food. The concern was whether crows imitated the ability to build tools instead of the information being acquired from another crow. A 2002 study found that crows could model tools on the spot, but another study found that this trait was not genetically compelled.
"New Caledonian crow tool designs could be passed on to subsequent generations if an individual used or observed the products of tool manufacture (such as their parents' tools), formed a mental template of this type of tool design (a mental representation of some or all of the tool's properties), and then reproduced this template in their own manufacture," the authors wrote in the study.
The Experiment On Crows
Researchers conducted an experiment on the memory of crows. They trained eight wild crows to drop tiny bits of paper into a vending machine in order to get food. The researchers said that the crows discovered that only small pieces of paper measuring a specific length would be accepted into the vending machine.
To test the memory of the crows, the researchers removed all small pieces of paper. Instead, they gave the crows large cards that were too big for the vending machine. The crows used their beaks to tear apart the paper to create the same sizes as the original small pieces of paper. The crows created small pieces of paper that matched the same length. To prove that the crows used their memories, the researchers ensured that they could not spot any other pieces of paper that were the same size as the first bits. That means it was all done from memory.
Future Implications Of This Crow Study
Although crows are not the only intelligent birds, this study could shed new light on animals. It could help scientists understand natural selection, memory, and how nonprimates pass down information.
"The prime limitation on our appreciation of avian intelligence is the lack of creativity in our own experimental methods," Edward A. Wasserman, psychologist and brain scientist who was not involved with the study, told Gizmodo. "Birds keep looking smarter as we conduct more ambitious and assiduous experiments."