#raven intelligence

Ravens Are So Smart, One Hacked This Researcher's Experiment ▶▶ link to original article

Evermore: ravens can plan for the future, scientists say ▶▶ link to original article

Ravens are members of the corvid family, a family which includes some of the smartest birds--indeed smartest animals--on Earth, including crows, rooks, jackdaws, jays, magpies, and nutcrackers. At some point, I may write a post summarizing key findings that have demonstrated that corvids are the intellectual peers of the primates and the cetaceans (dolphins and whales). For now, I refer you to this wikipedia page, these two peer-reviewed review article, and these two PBS videos.

This summer, I've had the good fortune of spending a bit of time with Vincent, a captive Chihuahuan Raven (Corvus cryptoleucus). I will be using this blog to keep track of my observations, the most interesting and novel of which I may consider publishing. Hopefully, video footage and photographs will follow soon. Very well then. Let’s begin.

Observations for May 30, 2011

Playing Catch

One of the most exciting developments was that Vincent has taken to playing catch with me. Yesterday, I brought him a ping pong ball which he thoroughly enjoyed playing with. I would throw it to him while he sat on his perch, and he would reach out to catch it in his mouth. On his first day playing with the ball, he would usually carry the ball around with him after catching it. He did a number of things with the ball: several times he attempted to cache it, while other times he would drop it and allow it to roll on his table before picking it back up. A number of times he set the ball down and pecked at it, pulling it back to its original position with his feet if it began to roll away. After pecking at the ball several times, he succeeded in pecking a small hole in the ball.

Today, I began throwing the ball to him again as he sat upon his perch, roughly 7 feet off the ground, about 4 feet in front of me. He watched excitedly as I would hold the ball and prepare to throw it, and would quickly move his head towards the ball once it was thrown, so that he might catch it. Initially, he would drop the ball after catching it; he showed little interest in carrying the ball around with him today. I would pick it up, throw it to him again, and the game would continue. Less than half an hour after I started throwing him the ball, he began performing one of two behaviors when I threw the ball to him. Sometimes, he would catch the ball in his beak, after which he would “spit” it out in my direction. At other times, he would not catch the ball at all, but would peck at it with his beak while it was in midair, sending it back in my direction. He seemed to alternate between these two behaviors at random. Whichever behavior he performed, it became quite easy for me to catch the ball. We continued “playing catch” for some times. Occasionally, his peck would be off mark and the ball would fly in the wrong direction, so that I was unable to catch it and had to pick it up off the ground. But this was not the typical case. In fact, the ball cycled between us as many as 10 times without touching the ground once. While further observation is necessary, I do not believe at this time that he was accidentally returning the ball in my direction, particularly since he was dropping the ball below him when we started playing the game. It seems likely to me that he began returning the ball to me because he enjoyed catching the ball and surmised he would get another chance to do so sooner if he returned to ball to me than if I had to pick it up off the ground.

Hiding and Recovering the Ball

One of the things I have been most surprised by when watching and playing with Vincent is the fact that he appears to enjoy mental stimulation for its own sake. He remains curious, attentive, and playful throughout the day, despite the fact that (at least to this point) no external reward has been offered or hinted at.

For this reason, little needs to be done to engage Vincent in play. If, for example, I take one of his toys and relocate it, Vincent will immediately attempt to recover it. Earlier this week I found that Vincent will quickly recover toys that are buried under gravel by digging with his beak, and that Vincent will recover toys that are hidden under upside-down bowls by prying beneath the bowl with his beak and flipping it over. Today, I wanted to see if he would recover a toy, if doing so required him to use both of these techniques. I buried his ping pong ball under gravel, and then put an upside-down bowl over the gravel, while he watched from his perch. When I moved away and sat down in my chair, he immediately flew down to the ground, flipped over the bowl, and scraped away the gravel until he was able to recover the ball. He recovered the ball within less than 30 seconds, indicating that he had no problem forming and executing a multistep plan to recover a desired item.

In the next experiment I performed, I wanted to see if Vincent would emulate a behavior that I showed him, which would allow him to recover the ball more quickly and efficiently. I placed the ball on the table, and placed an upside-down bowl on top of it. Vincent had already proven himself capable of recovering the ball from under this bowl using the prying method previously described, but the bowl was rather heavy compared to some of the others we had used for this experiment, and recovering the ball usually took upwards of 30 seconds. I wanted to see if he would learn to push the bowl off the table, allowing the ball to bounce free, if I demonstrated this technique for him. For the first trial, I demonstrated this technique for him three times, and then placed the ball under the bowl and allowed him to attempt to recover it. He did not emulate my technique, but rather, recovered the ball (after some time) using the prying technique. I then demonstrated the technique three more times, and allowed him to try again; again, he used the prying technique. After three more demonstrations, however, he landed on the table next to the bowl and pushed it over the edge, allowing the ball to bounce free. While it is possible that he may have used this technique in the past, it is nonetheless remarkable that he emulated my behavior after only 9 demonstrations. I do not doubt that he might have done so on an earlier trial, if it were not the fact that the prying method continued to be somewhat successful.

Untying Shoes

Although rather unimpressive compared to the other behaviors listed today, I should note that on one occasion today, Vincent landed about a foot in front of me, and took an interest with my shoe. He walked up, cautiously looking around, and proceeded to quickly grab one of my shoelaces and tug upon it. He then hopped to the other side of my shoe and tugged on the other shoelace, completely untying my shoe. I do not know if Vincent has seen a tied shoe before, if he has performed this behavior before, or if it is completely novel. In any case, it is a clear example of the inquisitive, mischievous nature of these remarkable birds.