ODD TRUTHS: THE LANGUAGE OF THE CROWS

For some thinkers in the Middle Ages, fluency in the “language of the birds” was a mystical and rare skill reserved for magicians and saints. As such, it was on a par with the mysterious language of angels, a divine speech that, when spoken, described the natural world with an accuracy beyond the reach of normal human intelligence. Thankfully, with the progress of scientific research, avian communication has become more accessible to the general populace. Nowadays, birdsong can be taught like any other foreign language. There are even birdsong apps!

Yet some bird behaviours are still mysterious. At the University of Washington, researchers are attempting to gain a better understanding of corvid cognition by studying the curious habits of crows. Kaeli Swift, a PhD student in U of W’s School of Environmental and Forest Sciences focuses specifically on the dynamics of “crow funerals”. We caught up with Kaeli to find out more about her research on this intriguing type of social expression.

The Custodian: Why did you focus on corvids specifically?

Kaeli Swift: I went to an undergraduate liberal arts school, so initially my focus was generally biology. I’ve always been really interested in the behaviour of social animals, particularly wolves, ever since I was young. Eventually, I started being more thoughtful about the kind of life I wanted to have as a scientist. Elephants, dolphins, wolves, are fascinating, but studying them requires a lifestyle with some degree of isolation in mind. While I was thinking about that, I started to get more interested in the research on corvids. My undergrad research advisor was a co-author on a paper focusing on facial recognition on crows, so that was a perfect introduction for me. It was a nice marriage–I knew I could work with a socially intelligent species in a variety of places.

C: You probably have been asked this so many times. What’s the difference between ravens and crows?

K: They’re in the same genus, but look different like lions and tigers. I think that’s a nice reference point for understanding it. In terms of intelligence, both are virtually on par with primates. John, (my adviser) calls them “little flying monkeys”. We see similar ‘funeral’ behaviours in a number of corvids but it hasn’t been systematically studied in ravens, as it has in crows.

C: Can you give us a description of the crow “funeral” ritual?

K: In a scientific context, we often describe these as “cacophonous aggregations”, meaning noisy gatherings around bodies. This kind of jargon isn’t always perspicuous in popular audiences, however, so I choose to use a certain degree of anthropomorphic loading in my terminology to better communicate these rituals to popular audiences. That being said, my use of the word “funeral” is something I’m continually questioning since I don’t want to convey that we have a deeper understanding of the emotional intelligence behind these rituals than we really do.

C: Why do the researchers use masks?

K: In the initial facial recognition study they used masks as a way to keep this control. That allowed us to postulate that it was the face that the birds were primarily paying attention to instead of skin colour, body shape, or gender.

One of the ideas we were looking at was whether they engage in this behaviour as a mechanism of danger learning. Specifically with respect to the place that they see these dead bodies in. We wondered, “are they trying to learn about novel predators”? So in our study, we substituted novel predators with people. We sent somebody out holding a dead crow and, depending on the study, the crows would see them the next day or the next week. We didn’t have the luxury of paid technicians, so by wearing masks, I could always keep the face the same.

In our experiments, we saw almost the same thing every time. The territorial pair would come in and put out an alarm call. Most of the time, that would result in recruitment of at least one other adult bird to the area. Sometimes it was one, sometimes there were twenty or more.

Once they recruited those extra birds, they would continue to make aggressive vocal sounds. Then there were pulses where the noises would get louder and louder and then settle down. After about 15-20 minutes, most birds would disperse. Sometimes the territorial pair left with the group and other times they remained.

C: Have you come across any data which shows that early societies incorporated corvid behaviours into their mythologies?

K: While corvids are pervasive throughout nearly all human cultures, most of that mythology is based on their appearance or general behaviours (monogamy, curiosity, consuming of human flesh etc.). While I haven’t come across any explicit reference to the kind of crow behavior we just described in our study, there is a Jewish folkloric tradition which talks about the reason people bury each other. Apparently a raven is the one that killed its companion and buried it to show Adam and Eve what to do with their dead son. The Greeks and Romans were aware of corvid love and devotion (monogamy), on the other hand, which is why two crows were a blessing at a wedding but a single crow was a bad omen.

Certainly the ‘funerals’ came to our attention because this is something that captures the public’s attention and interest. Take electric companies for instance. It’s not uncommon that a crow will get electrocuted to death by a transformer. When an electrician comes back to repair the power lines, he or she usually happens upon a corvid gathering. For people who experience these things regularly, our findings didn’t come as much of a shock. That being said, I wouldn’t be surprised to find that early cultures did incorporate this behavior in their mythology and I’d love to learn of any examples.

C: Recently you shared an article about birds collecting historical documents. What do you think about the feasibility of a field devoted to the study of human culture through the collections of bird ‘antiquarians’?

K: There’s little empirical evidence that wild corvids collect non-edible objects apart from New Caledonian crows. They use tools, and they hoard their favourite tools. Birds collect material as nest lining and occasionally that material is of great value to us, but most often it is not. With respect to crows specifically, it doesn’t happen enough to warrant that. On the other hand, birds like bowerbirds might make a more interesting area of study. Male bowerbirds make structures called bowers out of sticks. They’re basically walled gazebos with a little alleyway. That’s where the female sits when they perform. Male Satin Bowerbirds love the colour blue, so they decorate the platform in front of the bower with blue objects like flowers, berries, insects, etc. When these bowers are in close proximity to human homes, we see things like blue leggoes, bottle caps, and tarp fibres showing up in their decor. Studying constructions like this could be a really cool way to document the spread of anthropogenic trash and how that’s being utilised in the natural world. For example, hermit crabs are beginning to use sea trash as replacement shells. Another well-known example are the dens of packrats (middens) that can be thousands of years old and contain really natural and anthropogenic stuff preserved in them.

Want to keep up with Kaeli’s research? Have a look at her blog. You can also follow her on Twitter.

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