Ravens, like some great apes, plan ahead.
Raven planners. I’m Bob Hirshon and this is Science Update.
The ancestors of great apes and ravens diverged over 300 million years ago, but they have a surprising number of behaviors in common. One is the ability to plan for the future, once considered a uniquely human trait. Lund University cognitive zoologists Can Kabadayi and Mathias Osvath taught the birds that they could use certain tools to retrieve food and collect tokens to bargain with humans—behaviors they don’t exhibit in the wild. Later, the birds demonstrated that they could plan their tool and token use at least a day in advance, ignoring more immediate rewards that would have distracted more short-sighted animals like monkeys and dogs.
All birds succeeded convincingly in all tests. That’s a pretty impressive result.
The researchers write in the journal Science that the skill must have evolved independently in apes and birds. I’m Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
Much like the raven sitting on the bust of Pallas in the famous poem by Edgar Allen Poe, the ravens in this study are able to plan for the future. As humans, we know ourselves how hard it can be to delay gratification—to put off buying that new shirt we want or getting the latest electronic gadget. Sometimes, however, it's necessary to put off buying something today so that we can save money to be able to afford to do something else in the future—like going to college.
Scientists once thought that the ability to plan ahead for future needs—and to sacrifice our current desires for gains in the future—was a distinctly human trait. Nearly a decade ago, however, Mathias and Helena Osvath conducted a study that showed that great apes, like chimpanzees and orangutans, showed advanced planning capacities. (This study appeared in the March 9, 2009, issue of Current Biology.)
Research has continued to build on this finding and this new study by Can Kabadayi and Mathias Osvath at Lund University demonstrates that ravens could be another species that has the ability to plan ahead.
In order to conduct this research, Kabadayi and Osvath designed a series of experiments with five captive birds to see if ravens could plan for an unseen future. First, the birds were shown a box that had a tube sticking out of the top, plus three stones. They learned that they could use a stone as a tool. If they dropped it down the tube, the box would release a doggie treat. The researchers then took the box and the tool away. An hour later, however, the ravens were presented with a tray containing a stone plus three objects the birds knew would be useless. The birds were allowed to choose one thing from the tray. Fifteen minutes later, the box would show up again. About 80% of the time, the ravens chose the correct tool and performed the task to get their treat.
To further test this possible planning ability in the ravens, the researchers repeated the experiment but this time with a 17-hour delay in returning the box. Again, the birds were successful—this time 90% of the time.
Another experiment the researchers set up tested the birds' bartering skills. They learned how to trade a blue bottle cap in order to get a kibble treat. Then the researchers set up another experiment in which the ravens could choose between an inferior immediate food reward (a smaller, less-tasty piece of kibble) and a token for their favorite kibble they could trade later. The ravens selected the tool or token that would get them the better food in the near future over 70 percent of the time.
The results of these experiments are compelling but further research needs to be conducted to discern exactly how clever ravens are.
Now try and answer these questions:
- What is delayed gratification?
- What other species are believed to be able to plan for the future, like humans?
- How did the researchers test the ravens in order to determine if the birds could plan for the future?
- Do you think the researchers could have tested the birds in different ways in order to test their hypothesis? In what ways?
- How would you set up an experiment to see if an animal could plan ahead, like humans?
To learn more about this research, you can watch the Ravens—Like Humans and Apes—Can Plan for the Future video from Science.
You can listen to the Parrot Learning Science Update to hear from a researcher who believes parrots may develop language-like communication and other abilities in ways similar to humans.
This Science Update ties in nicely with lessons or units you may do on learning—either in humans or other species. You can use the Science Update and the Ravens—Like Humans and Apes—Can Plan for the Future video from Science to engage your students in the topic. After students listen to the Science Update or watch the video, you can engage them in a brainstorming session in which they should come up with other hypotheses about animal cognition they could test and how they would go about doing that.