Today I have some very new research, and a very old story. First, the new…..
The carrion crow has become only the third (known) member of a very exclusive club, one made up of those beings that can have subjective experiences. Beings that are aware of what they are perceiving. Beings that are conscious.
So say Andreas Nieder, Lysann Wagener, and Paul Rinnert of the University of Tübingen in Germany in their September 25 publication in the journal Science.
AUDIO: The many calls of the carrion crow
These researchers trained carrion crows to report whether or not they’d seen a flash of light. Sometimes it was bright and easy to see, sometimes it was dim and near the threshold of their ability to detect it, and sometimes there was no flash at all. The crows wouldn’t know how to report what they saw until a few seconds later, when another cue was given. This way, they couldn’t prepare a response until they were asked, so they’d have to judge, remember, and decide whether or not they’d seen anything.
During this process, the individual electrical activities of hundreds of the crows’ neurons in an area called the nidopallium caudolaterale (NCL) — the bird analog of the cerebral cortex in primates — were monitored.
A large group of these neurons would always fire if any flash of light were shown, regardless of whether the birds later reported they’d seen anything. So these neurons amount to the primary raw signal, just an involuntary and unconscious response, a reflex.
But there was a second, smaller group of neurons that fired only in those instances when the birds went on to report they’d seen something. This group of neurons made up a secondary signal that didn’t always correlate with the primary raw signal. It did correlate really well when the flash was bright or when there was no flash, because then the decision was obvious. Bright flashes were reported as seen by the birds pretty much 100% of the time.
But when the flash was dim, the birds reported they’d seen something about 50% of the time. The primary neurons always responded to a dim flash, because the brain had in fact been stimulated, but those secondary neurons only responded about half the time, and it was the same half in which the birds reported seeing something. So somewhere between the primary and secondary neural responses, a subjective interpretation and decision was made. Did I just see something, or not?
This two-stage process is similar to what happens in humans and macaque monkeys, the only two other kinds of animals to have what we’d define as consciousness.
But how can birds do this without a cerebral cortex, the part of primate brains that allows this two-stage, “conscious” response?
A second study in the same issue of Science (September 25) shows that while the NCL doesn’t look like a cerebral cortex, it is actually organized in a similar way, and this layered neural structure had not been noticed until now. It isn’t just the carrion crow, either; this kind of brain structure was shown to be present in pigeons and barn owls, two bird species that aren’t all that closely related to one another.
Together, these two papers amount to a new way of thinking about the avian brain, writes Virginia Morell for Science:
The two papers are already being hailed as groundbreaking. “It’s often assumed that birds’ avian brain architecture limits thought, consciousness, and most advanced cognition,” says John Marzluff, a wildlife biologist and specialist on crows at the University of Washington, Seattle, who was not involved with either study. Researchers who have “demonstrated the cognitive abilities of birds won’t be surprised by these results,” he adds, “but they will be relieved.”
Marzluff had a more-succinct quote for STAT News:
“It has been a good week for bird brains!”
But I said at the beginning that I have an old story, too.
Today in 1918 (September 26), the Allies undertook their final large-scale attack of World War I, the Meuse-Argonne Offensive, which would ultimately seal the Germans’ fate and win the war. There were many human heroes, such as the Harlem Hellfighters, whose great sacrifices and valor we should never forget.
Another group of valiant American fighters was the Lost Battalion, about 550 men of the 77th Infantry Division who were cut off and trapped behind German lines for many days of intense fighting. They weren’t really “lost”; they just penetrated farther than the stalled French and American units that were supposed to be supporting them.
Once the Germans realized that they had the 77th surrounded, they began to close in and attack. The unit had no way to get food, ammunition, or medicine, and the Allies couldn’t penetrate the German lines to do anything to help. After a couple of days, it appeared, to the great relief of the 77th, that airlifted supplies were finally arriving, but the Allies had actually lost track of the position of the Lost Battalion, and, thinking they were shelling the Germans, inadvertently began dropping fire on the 77th and causing several casualties. This couldn’t go on, or it would be doom for the 77th.
The unit had no way to communicate their position except by carrier pigeon, and they literally had only one carrier pigeon remaining, albeit a reliable favorite who had successfully delivered a dozen previous messages by the name of Cher Ami (“Dear Friend”).
This time the last-resort message was a matter of life and death for the men who had not already been killed, wounded, or taken prisoner:
The message was placed in a small canister and tied to Cher Ami’s left leg, and she was tossed upward. She settled in a tree for a minute, aware that there was much ammunition flying all around her, but after some egging on by the men, she made her run for it. Just moments into her flight she was hit by a German bullet and started to dive, and the men groaned. But she managed to get her wings back out and pull herself up, flying 25 miles back to an Allied position to deliver the message.
By the time she got there, she was badly wounded and bloodied, her right leg hanging from a tendon, a bullet wound to the breast, and one damaged eye. But her refusal to quit ultimately meant that 194 men made it out of that dire position and survived.
After the Armistice on November 11, for her bravery and service, Cher Ami was awarded the Croix de Guerre with Palm, one of the highest military honors that the French government can bestow. She is the only animal ever to be presented with this award.
Cher Ami returned to the United States, seen off from France personally by General John J. Pershing, and became a popular hero. She sported a wooden leg made for her by the men of the 77th, but unfortunately she didn’t last very long, dying of her wounds on June 13, 1919. She was barely more than a year old.
Cher Ami’s remains are on display at the National Museum of American History within the Smithsonian Institution, alongside her Croix de Guerre.
Now this is a bird who knew what she was doing.