Crows Using Automobiles as Nutcrackers: The Evidence

[Benton Library Media Center]

This is Mrs. Corey posting as Benton Library again. :)

There's a great amount of evidence, both within peer-reviewed academic journals and in other sources, surrounding crows and their use of tools. One of the great examples is the observation of crows using automobiles as nutcrackers. It appears that the first evidence to appear in any journal was an article by Terry Maple in West Birds in 1974. The original article cites "multiple observations" of crows dropping walnuts onto a busy street near UC-Davis. Not much literature is cited, nor is his evidence well-documented. However, this article definitely started a discussion concerning tool-use by crows that is still going on to this day.

In 1997, some researchers at UC-Davis wanted to put the case to rest. They documented their observations and accounted for statistical inaccuracies. They determined that this tool-use was a common misconception by casual observers but do not entirely discount the possibility. The researchers even discuss the following:

In fact, using cars as nutcrackers might not be advantageous to crows. When a nut is crushed by a car, a single bird can no longer monopolize the nut, because the meat adheres firmly to the road surface.

However, the debate has continued. An article published in 1999 in Behavioral Ecology (again, peer-reviewed) supports the idea of crows using automobiles as tools for cracking nuts. I wanted to point out how long the peer review process can take. Here's a screenshot of the submission and acceptance dates for this particular article:

Not surprisingly, non-peer reviewed sources like Wikipedia cite this behavior (see the entry regarding Crows - Intelligence. And YouTube has a great video showing these crows in action:


So bringing this back to the idea of "right" and "wrong" information . . . you can definitely see this issue isn't black and white. It's much debated and the evidence is varied. If we were to assign shades of gray to each source, which would be darkest?

Image:

"Hooded crow with a nut" by Kristof Borkowski via Flickr, available under a Creative Commons license.

[Marcy Withrow]

If darkest would be the more correct resource, I would have to say the darkest is the resource that does not support crows using automobiles. At first I was thinking "Well, birds are intelligent creatures, this could be a possibility!" But, as I went back and looked at the resources, I found that the article was more supporting and believable than the video. As I watched the video, i found it kind of cheesy. How exactly do you get birds to do the exact thing you want them to on video and know perfectly their next move? I've seen animal planet, but this video seems just a little too fake; compared to the article. The article comes from educated people who have done an experiment, showing that crows do not use automobiles, they simply drop it on concrete to bust it open, with or without cars. In conclusion, I believe the resource saying "crows do not use automobiles" is more valid than the video saying they do.

[Shandis Cruz]

I'm going to have to agree with Marcy on this one. I too believe that the darkest information is not at all the youtube video. Although, it did take me a little while to determine that. After watching the video I visited the home page of the person that posted the video, "concretejungle" I believe was the name. That right off the bat sent up a red flag for me. For one the name doesn't lead that they are anything legit, so I dug a little deeper to find if they had some kind of further research backing the video, needless to say I didn't find it. I was also unable to discover any credentials for that person, so that really steered me in the opposite direction, I took this as more of an opinion based video that this person posted.

As I read into the topic a little more I found lots of mixed reviews. But throughout reading all of the different journals and sites I have come to the conclusion that I am still undecided. I took into consideration the amount of biased opinions coming from both sides of the argument and they really do both make sense to me. I do agree that crows have the capability of using automobiles because it has been done and recorded.

But as far as them using this method as a constant I am not for. I believe that they do indeed have the capability of doing it, I just think depending on the bird and what its learned to do is whether or not the technique will be used. That is why I'm going to be completely honest in saying that I am not for or against either side. Because I think they both hold strong arguments...this is just a topic that I'm going to have to dig even further into.

[Benton Library Media Center]

Not coming to a conclusion is perfectly fine . . . even the authors of all of these peer-reviewed articles haven't come to a conclusion on the issue.

Really, that's one of the whole points of the peer review system . . . to look at the information/evidence/methodology presented by previous researchers and simply pick it apart. Because researchers are building upon the work that's been done prior, they are building upon and improving that field. That's what makes peer review self-correcting . . . the research that is faulty can someday be corrected by a new researcher.

So really, your job as a student researcher is to take a glance at the current information landscape and decide where it fits in on that whole spectrum of white to gray to black. There's really not one right answer and there are lots of ways of performing that evaluation. For instance, the YouTube video may be the most recent information (currency) but as you all found it might not be backed by other sources (accuracy). The 1999 article in Behavioral Ecology is peer-reviewed (authority) but not as recent (currency) but has lots of references to back it up (accuracy) and doesn't show bias (content).

See how easy that is? Well, not really . . . because you can be overwhelmed when you're not dealing with 4 or 5 sources given to you but this vast amount of information out there.

But I must say that I am so IMPRESSED with how you are looking at this issue. You guys don't settle for an easy answer and that's great! You really are doing a perfect job of researching . . . evaluating resources, using your own background knowledge, synthesizing your findings. It's really, really, really great!

Keep up the good work! :)

[Sean Nash]

@Shandis - I am interested in your "gut feeling" about the person's screen name. I think it is very telling that you were initially put off by the name and were already not going to be terribly surprised to not find supporting evidence for this issue.

What you speak of deals with many things... one of which could be said to be a person's "personal branding" or marketing. Do people pay attention to the "image" or "brand" they create for use in online spaces? What does this brand say about a person? How might that be important to an individual as time passes?

[Taylor Woodruff]

Well... I'm going to have to say that I really don't know what to think about the crows using automobiles as nutcrackers. A lot of the sites that we were linked to gave me some pretty good evidence that the crows are smart enough to use automobiles, but like Mary and Shandis said, the video wasn't very believable and was definitely more on the lighter side. It also makes me wonder how the filmers knew the exact time and place that the crows would be dropping the nut.

So, I'm going to have to say that since there's a lot of details that support and and that pretty dis the crows being smart enought to use automobiles as a nutcracker, that I honestly have no idea what side to be on. I guess I'm just going to have look more into it...

[Taylor Woodruff]

whoops sorry Marcy..I forgot the "r" in your name above :p

[Marcy Withrow]

haha, it's okay, it happens all the time (:
But yeah, the video was VERY strange.

[Coleman Wade Babcock]

i have to agree with shandis and marcee on this. i could tell by the video that the shots were set up to make it seem that the birds were intentionally using the cars as nutcrackers but i just didnt bye it. I know that you can get a shot then get it together with another shot that makes it appear to be intentionall but there was to much that was, as marcee said "cheesy". there also was to much stuff on the databases that i looked up in class and there was really no evidence that made me say "wow they could be intentionally doing that".

it could just be a coincidence (sorry for the spelling) that the birds are doing this but to say that they are intentially doing this and more than just a group of birds are doing this, seems kind of rediculous. Birds are not that smart so i have to day its bogus

[Blayr Bolton]

Oh my. I'm going to definitely say I don't believe that video for a moment. It looks very staged to me. Especially because nothing that happened was filmed altogether. It was the crow dropping the nut. The nut being cracked. And the crow retrieving the nut. It looks like this was all done separtely and thrown together to look as one. I'm not sure if this guy was just trying to show the jist of what happens or if this was meant to be proof of this arguement, but either way it fails. So, yes the youtube video is very white. Maybe extra white. ;)

Besides the video. Even though the video may be completely unbelievable, I just may believe that crows use cars as nut crackers. Terry Maple in West Birds in 1974 might have weak currency, but he gives a convincing presentation. I like his positive and negative aspects he throws into his work. Researchers at UC-Davis (white content) claim that the nuts getting hit by the car is just 'accidental.' But, I'm wondering about all of the crows that they haven't spent their lives around studying. The crows they watched may not have steadily dropped nuts in the pathways of cars, but what about other crows in the U.S.? Or even outside of the U.S. Article published in 1999 in Behavioral Ecology honestly had a little too much accuracy for me. I''m not sure if that makes sense, but it was too research and graph based for me to even want to read. That sounds terrible, but it's true!

Overall, I definitely think that it's possible that crows use cars to crack their nuts. I mean, have all of these researchers and scientists honestly observed every crow on earth? I doubt it. It could just be their field of crows that wasn't straight up using the cars. You never know. :) Maybe I'm being to optimistic, but it certainly seems logical to me that it's a possibility.

I'm just curious who would start an arguement over this topic? It seems to be a pretty huge debate, but about crows? :) Interesting.

[Shelby Hawkins]

Wow, I'm having trouble seeing why this is such a big debate. I'm still on the fence, I definitely think crows are smart enough to do it. The video was probably set up just to illustrate the pro-smart crow side, and not represent any theories against it. So, the video was biased. Shandis also said the author was not very credible, which is also a huge deal. However, there are articles out there with authors who are titled and peer reviewed. Overall, I think more research needs to be done.