Long read: Why birds don’t buy Bentleys and we humans will never fly

Human beings have been the dominant species on the planet for a while now. Not just dominance but also unique in terms of our ability to establish culture and transmit it from generation to generation, something that no other species has managed to come close to exhibit through evolutionary history. The only species or rather class of species that resembles humans in terms of capabilities to have achieved this is apparently birds.

“The philosopher and biologist Peter Godfrey-Smith points to birds as the expected place to find another species treading the same path that we humans have, not least because they already come with several of the important adaptations that made cultural sharing possible for us: complex brains, long lives, strong parental care of offspring in most species, and robust communication.”

The reference to complex brains might come as a surprise to many of us who often use the ‘bird brain’ remark to refer to low IQ: “…birds’ small heads actually contain very large numbers of neurons, thanks to adaptations that have shrunk the size of their individual neurons to fit in a smaller package. As a result, their forebrains (the thinking part) have neuron numbers to rival primates.”

Yet, birds have fallen short of humans when it comes to cultural transmission. Why so?

The answer like with most questions of nature lies in evolution, explains Antone Martinho-Truswell, an evolutionary biologist, in this rather entertaining essay, full of metaphors from topology to astrophysics.

“Natural selection (and, by extension, evolution) is a force with no foresight. It responds to the challenges that a species is currently facing. It does not, and cannot, ‘see’ broad sunlit uplands on the horizon and move toward them. This is because selection is a game of elimination – it happens when individuals die without reproducing, or having reproduced less than their neighbours. In each generation, that which is unsuccessful is culled by natural selection, and that which is successful endures.

…Humans obviously exist at a highly optimised state of evolution. We have conquered the planet. We reproduce prolifically and we live much easier lives with more abundance of basic resources than any other animal.

A great deal of our success results from being a cultural species. To take only the brusquest example of this, our complex culture enables things like specialisation, commerce, transportation and trade; thus, in developed countries, only a small percentage of humans are involved in sourcing food for the whole rest of the species. The average human spends a trivial amount of his or her life in pursuit of food. This is an unheard-of level of plenty, compared with even our closest relatives.”

What about birds?

“And birds, like some primates, do have simple cultural transmission, just enough to tempt us to consider why they don’t have more complex capabilities. In one study, scientists wearing a distinctive, grotesque mask trapped and released American crows. The crows quickly learned to associate the mask with danger, responding with alarm calls and mobbing when they saw it again – even years later. More intriguingly, crows that were never trapped but had observed others respond with alarm also learned to fear the mask. This response was observed across years and appeared in new generations, suggesting that the information was socially transmitted, likely through both observation and vocal cues.

Indeed, birds have traits that suggest the emergence of true culture far more consistently than many mammals. Birds live longer and are far more likely to attentively raise their offspring than comparably sized mammals, and their cognitive abilities and communication are easily on par.”

Why then do birds not exhibit complex cultural transmission? The answer lies in their most obvious distinction – that they can fly.

“Flight is an incredible adaptation. It opens an entire third dimension of free movement to species capable of flying. First and foremost, this is game-changing for a prey animal. Being able to escape a predator by travelling in a direction the predator is incapable of going, namely, up, is a huge selection advantage. A flying animal is at risk of consistent predation only from other flying animals, which are fundamentally rare. Moreover, flight limits size and weight, so a bird at the higher end of the flying spectrum is unlikely to have many flying predators large enough to cause her much of a problem.

The reduced risk of predation is in turn why birds live so long. It creates a virtuous cycle where each subsequent year of the bird’s life has a higher potential reproductive value than it would if they didn’t fly, which in turn drives the evolution of robust repair mechanisms in the body, of slower but more attentive reproductive strategies, and of a longer natural lifespan. Together, these are a suite of traits that biologists call ‘K-selected’ – basically, the ‘live slow, die old’ strategy.

Flight also provides access to resources not available to the landbound. All manner of food sources and safe habitats become available when an animal can fly – from tall flowering trees’ nectar and fruits, to inaccessible cliffside perches, to stronghold-like tree hollows for nesting. It opens up completely vacant niches that can be exploited only by fellow flying species.

All of this is to say that evolving the ability to fly removes a huge amount of selection pressure from the species that have it. It makes life easier. It is itself a deep, low well in the evolutionary landscape. It is a very, very massive gravitational object pulling in species and keeping them in its sphere.”

If you want to read our other published material, please visit https://marcellus.in/blog/

Note: The above material is neither investment research, nor financial advice. Marcellus does not seek payment for or business from this publication in any shape or form. The information provided is intended for educational purposes only. Marcellus Investment Managers is regulated by the Securities and Exchange Board of India (SEBI) and is also an FME (Non-Retail) with the International Financial Services Centres Authority (IFSCA) as a provider of Portfolio Management Services. Additionally, Marcellus is also registered with US Securities and Exchange Commission (“US SEC”) as an Investment Advisor.