The irony of “Bird Brain”

by Hinal Kharva – It’s high time that we don’t use the term “Bird Brain” for calling someone stupid. Well, a recent study in journal Science this week showed that birds like crows show higher intelligence and consciousness (awareness of one’s own existence and surroundings) like humans and monkeys. Ugh, I have been waiting to say “birds are so smart’’. 

As an insect neurobiologist, I can definitely say that even though insect as well bird brain sizes are much smaller than primate/Human brains, the functionality of their brains are quite fascinating. 

The anatomical structure of the brain is quite different in birds and Humans/mammals. A bird’s brain lacks the region called the “cerebral cortex” which is present in mammals and also plays important role in attention, perception, awareness, thought, memory, language, and consciousness. However, birds do show some level of consciousness and self-awareness without a cerebral cortex. One of the recent studies in Science was about higher intelligence centres in the bird brain. They looked at the neuroanatomy of homing pigeons and owls. High-resolution imaging helped the researchers to understand the neuronal connection in the frontal region of the bird brain, called the Pallium. Interestingly it is very similar to the mammalian neo-cortex. This neuro-architecture, which is basically the connection between the different structures in the brain, explains why birds can accomplish some of the same mental gymnastics as mammals.

Let’s look at the two different examples of cognition and consciousness in birds.

The first study talks about the self-awareness in Magpies. Scientists from Ruhr University and Goethe University in Germany have been studying cognition in birds for many years and their recent experiments showed interesting results on self-awareness in magpies. Other than Humans, some species of dolphins, elephants, and other primates have shown the ability for self-recognition. They took a lab trained magpie, named Gerti, out of her cage and put a yellow sticker on her black throat region which would be only visible to her in the mirror. They placed her in a cage with a mirror and observed her behaviour on a monitor. She looked at the mirror and immediately started scratching and tried to remove the sticker with the help of her beak and foot. They repeated these experiments using a black sticker, as well as in the cage without a mirror. The results showed that sticker-extracting behaviour occurred only when the bird could see a mark in the mirror. Even other magpies behaved similarly, and thus scientists concluded that Eurasian magpies were able to understand that they are seeing their own reflection in the mirror. Here is the link to the video of the same experiment: https://www.youtube.com/watch?v=HRVGA9zxXzk

The second study is about consciousness in crows to understand if birds are aware of what they see and do, and whether they experience consciousness. One way to test this is via recording the neuronal activity in different parts of the bird brain, to decide which parts are more likely to light up when birds are “thinking” to respond to particular cues. Andreas Nieder, a neurophysiologist at the University of Tübingen, performed some experiments on carrion crows (Corvus corrone). They trained two lab-raised 1-year-old crows to either move or stay still in response to a faint cue which was displayed on a screen. If birds gave a correct response, then they were rewarded. Researchers also fixed some electrodes in the crow’s brain to record the neuronal activity while they gave the response. Interestingly, when the crows reacted to the stimuli, the neurons fired in the particular brain region called “pallia”, and when they did not react to the stimuli, the neurons remained silent. This bird brain region, the pallium, has neurons that represent what it perceives—a hallmark of consciousness.

As a whole, these basic and yet fundamental discoveries are very exciting, as they suggest that the building blocks for mammalian and avian cognition may have been present in their last common ancestor, which existed some 320 million years ago. Both, mammals’ and birds’, brains have evolved differently and still show similarities in their sensory and cognitive abilities, like convergent evolution. Finally, understanding the minds of non-human animals can also provide insights on the origins of such cognitive abilities in the animal kingdom. 

References:
1. Prior H, Schwarz A, Gunturkun O (2008) Mirror-induced behaviour in the magpie (Pica pica): Evidence of self-recognition. PLoS Biol 6(8): e202. doi:10.1371/journal. pbio.0060202
2. Nieder A, Wagener L, Rinnert P (2020) A neural correlate of sensory consciousness in a corvid bird. Science: Vol. 369, Issue 6511, pp. 1626-1629 doi: 10.1126/science. abb1447
3. Stacho M, Herold C, Rook N, Wagner H, Axer M, Amunts K, Gunturkun O (2020) A cortex-like canonical circuit in the avian forebrain. Science: Vol. 369, Issue 6511, doi: 10.1126/science.abc5534
4. Blog by Sharon Begley, September 24 (2020) Brainiacs, not birdbrains: Crows possess higher intelligence long thought a primarily human attribute. @statenews.com

5. Blog by Virginia Morell, September 24 (2020) Newfound brain structure explains why some birds are so smart—and maybe even self-aware. @sciencemag.org

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: