Crows and Tool Use Cognitive Processes Associated with Sequential Tool Use in New Caledonian Crows

What was the study?

The goal of this research was to study sequential tool use in New Caledonian crows. Tool use is a behavior we see across many species, namely those more known for their intelligence-many apes and monkeys, for example, crows, and of course, people. This study was deisgned to build on the knowledge we already have, that being that crows are known to be capable of using and even creating tools. Here, we see if the crows can take this a step further, by using multiple tools in sequence in order to complete tasks.

How was this research conducted and measured?

The researchers used more than one experiment to study this, though they all follow the same concept. They used crows, both some that were familiar with similar tasks and some that were not, and presented them with tools in tubes, a tool that would allow them to retrieve the tool needed, and a box with food that require the second tool to retrieve. The tubes had various sizes of tools, not all of which would be effective for the task. They then recorded how many attempts it took the crows to retrieve the second tool with the first, how long it took for them to get the treat itself with the second tool, and how many tools the crows picked up before choosing the correct one. This is studying the sequence of first retrieving one tool, then using that to retrieve a second, and then using the second to retrieve the treat and complete the task.

What did we find?

Many of the crows demonstrated an ability of sequential tool use in order to complete a task. Not only were many successful in completing the task, but in analysis of tool swaps-moments where the crows switched which of the second set of tools they used before attempting to get the treat-they found that the crows tended to make good swaps; they were more likely to look at the situation at hand, and switch to a more useful tool before even attempting. Crows also tended to improve at this skill with more trials. This shows that the crows can in fact use sequential steps to complete a task, and that they seem to be capable of higher critical thought in order to do so.