Bird Brain: When size really doesn’t matter
They’re on our coat of arms, but from my most recent experience when camping last summer, I’m hoping that emus aren’t a representation of our national education system. With glowing red eyes, a misty grey plumage and a low booming mating sound resonating from a throat almost a meter in length, the female emu trespassing on our camping site cut a rather impressive figure…until she tripped over a branch, walked into the fire and tried to peck our eggs out of boiling water.
Watching and snapping pictures from the safety of our tents we realised that the second largest bird in the world, Dromaius novaehollandiae,with prehistoric tridactyl feet, was looking increasingly goofy as she tried to pick an egg out of boiling water five times, almost ran into the fire twice and tried to drink the fuel, before we hustled her away. Someone snorted “What a bird brain…” and we all laughed, secure in our own Homo sapien cognitive capabilities.
But as we sat around the fire with our big brains comfortably attached to our necks, we began swapping stories of feathered tricksters, ravens who could open school-bag zippers and Tupperware, cockatoos who knock on windows for food and Alex the African Grey parrot, famous for his way with language and whose last words when he passed away in 2007 were, “You be good, see you tomorrow. I love you.”
“Of all the animals, man has the brain largest in proportion to his size.”
Early hypotheses often used brain-to-body-mass ratio as a rough estimate of intelligence in animals. If that was the case however, Homo sapien ‘exceptionalism’ might be side-lined by the mere ant, whose brain is a seventh of its total body weight, or a shrew which holds 10% of its mass in its brain (the adult human brain is a mere 1/50thof its total mass). Luckily, neuroanatomists developed a consolation prize, the “encephalisation quotient” (EQ).
Ummm…are you sure you don’t mean IQ?
EQ, developed in the late 19thcentury takes into account the weight of the brain, body and allometry, a physiological scaling factor.
Using this scale, humans ranked first with our egos in place, at 8 EQ, Chimpanzees at 4.2 EQ, with parrots and corvids (crows, ravens and magpies) close to primates at approximately 4 EQ.
Is it only PROPORTION that matters?
A 2016 study found that avian brains have more neurons per area and are more densely packed than in primates of the same mass. The pallium (cerebral cortex equivalent) of parrots and songbirds were found to have similar organisation to primates but with a greater proportion of neurons. This increased neural density of the pallium which supports an animal’s ability to plan and find patterns could potentially give avian brains greater cognitive power per area than larger mammals.
Rock a bye…birdy?
Neuroimaging in songbirds has also given an insight into the dreams of birds, specifically, zebra finches. A 1998 study found that when the birds sung, electrical impulses from the robustus archistriatalis (RA) showed up as regular oscillating activity and when the birds slept, their RA showed less oscillating but still highly active impulses, suggesting the songbirds dreamt of segments of their own song, or consolidated songs they learned during the day.
Myth sharing in a murder of crows
Wildlife biologists put into practice whether crows can recognise those who have wronged them. Wearing a ‘caveman mask’, scientists tagged several crows, measured neural responses, then released them on Washington University campus. They found in the following months…and then years…whenever students donned the ‘caveman masks,’ nearby crows would flap, caw and swoop persistently, even if they hadn’t even been born when the study was first conducted! And when a dead crow was presented to caught live crows, the amygdala–emotional memory – and the hippocampus– long term memory formation – showed a burst of activity during neuroimaging, suggesting the crows understood the death of one of their ownand the danger this ‘caveman’ presented.
Much like how parents pass on the fear of the bogeyman, myths of dangerous cavemen who hassle and tag you can be passed among crows.
This learned behaviour has also been observed in crows in a district of Japan,who leave nuts on pedestrian crossings, wait for cars to break open shells and coordinate collection with traffic lights. Since this behaviour was first observed, locals have noticed numerous crows lining up at walk-ways, waiting to retrieve lunch and shells littering pedestrian crossings.
While many of us struggle to remember where we left our keys or phone, jaybirds exhibit tremendous recall, retrieving hidden seeds and nuts. The New Caledonian crowis the handyman we all need in our lives; bending wires to fish out baskets and even their own feathers to nudge out juicy grubs and the Heron is a skilled fisherman, using insects and leaves as bait by casting them out into water.
With their incredible potential for learning, it seems wrong that corvids and parrots are chided for squawking in a language we don’t understand. So rather than treating ravens as pests and lording our own cognitive prowess, perhaps we could take an example from a French theme park which has delegated several ravens to picking up rubbish – rather than pulling it out of bins – and enter into a partnership with the Aves.