Bird Brains and Behavior: A Synthesis, by Georg F. Striedter and Andrew N. Iwaniuk
The MIT Press, 2025
296 pages, paperback
For a dense treatise on avian neurobiology, replete with graphs and jargon, the first sentence in the opening paragraph of Bird Brains and Behavior: A Synthesis is disarming. “Watching birds is fun,” write coauthors Georg F. Striedter and Andrew N. Iwaniuk, both professors whose published work on bird brains is prolific in a field burgeoning with new discoveries and unanswered questions.
Mostly reading as a textbook for serious study, Bird Brains and Behavior contains lucid passages of general interest and otherwise broad statements peppered throughout. They lighten the load of an unrelenting outpouring of investigative exposition on experimental research that connects the dots between observable behavior and cerebral functioning in birds. In the process, anyone interested not only in avian diversity, but also in the scientific process and in vertebrate anatomy while unpacking the physiological puzzles of life, will find intellectual nourishment in the patient, explanatory work of these authors whose vanguardist knowledge is on admirable display.
From a human perspective, the story of bird brain evolution can be said to begin approximately 300 million years ago, when the reptile and bird lineages split (birds are within the reptile lineage). To parse the fundamental difference between cognition in mammals and birds, the authors employ an enduring insight by animal psychologist Irene Pepperberg, best known for decades of research with Alex, a Gray Parrot. Pepperberg likens mammalian and avian brains to early computers developed by IBM and Macintosh. Both include information processors with the same wires, only these fibers are organized differently. Using their respective configurations requires unique programs.
Bird Brains and Behavior offers a variety of stunning facts that overturn the stereotypical image of avian cognition as emblematic of dull-wittedness. As the authors write, at the start of the chapter on complex cognition, “Many birds exhibit complex cognition, making it ironically misleading to call an ignorant person a ‘bird brain.’”
Birds, as Striedter and Iwaniuk detail with empirical data, not only show advanced cognitive function like tool use, language faculties, and episodic memory, but also embody a wide range of impressive physiological adaptations. The most obvious of is flight, crucially dependent on sophisticated brain functioning.
Consider the Wedge-tailed Eagle. Its visual acuity is almost five times sharper than that of a typical person. This ability to see minutely from afar is not only beyond the photoreceptor density and neural processing of human biology, but also would require 300+ pixels per degree to replicate in any instrument. Even if the technology were to exist, human sight would have to evolve first.
Consider also the Pied Flycatcher, with a flicker-fusion rate of up to 145 Hertz, a touch quicker than the Peregrine Falcon—and more than twice the capacity of humans to follow fast movements. For perspective, when humans watch a film, light is projected through film that moves at 24 frames per second. But for Pied Flycatchers species, eight to thirteen as many frames would be required, projecting at up to 300 frames per second for that bird to theoretically watch a film relative to its optical neurobiology.
And birds do watch films for science. Striedter and Iwaniuk cite a study examining pigeons watching David Attenborough’s Life of Birds with either the left or right eye patched to detect how sleep refreshes different parts of their brains. Interestingly, neurobiological dualism recurs in more ways than one in the avian body. Certain birds are what is known as bilateral gynandromorphs, meaning that one side of them has male characteristics, the other female. Finally in terms of birds’ vision, many species, such as hummingbirds, perceive UV wavelengths, as they have evolved to have an advanced set of photoreceptor pigments. And in this area, Striedter and Iwaniuk agree that scientists still have more to learn.
What about the non-visual senses? Hunting in pitch black, American Barn Owls have a keen sense of hearing with their asymmetrically situated ears. Despite previous assumptions that devalued birds’ sense of smell, scientists are finding a wealth of evidence indicating a rich resource that contributes to neurologically sophisticated behaviors like migration, hunting, nesting, and mating. As for the fancies of the bird palate, Striedter and Iwaniuk report that, for songbirds at least, avian neurobiologists “know essentially nothing about the neural basis of taste discrimination.”
Birds are capable of adaptive learning. With their relatively large hippocampi, they create mental maps that enable to imagine and plan for what is to come. This is crucial for retrieving stored and navigating through space and time. Sensitivities to gravitational and magnetic fields further the perceptual range by which birds remember everything from flowers to landmarks with episodic vividness. This extends into social behavior mirroring even more unscrupulous aspects of human life. Male Budgerigars monitor their mates’ location for extra-pair courtship. Desperate Nest-Wives, anyone?
Avian attainments rival those of humans in the fields of robotics, but what about avian culture? Striedter and Iwaniuk adduce charming factoids like pigeons’ ability to tell the difference between a Monet and a Picasso, but avian culture is rich and complex indeed. Birdsong, which has impressed humans through the ages, remains a fertile area of research; more than merely beautiful, avian vocalizations are, according to the authors, in certain respects, “more extensive than that of any other complex social behavior, including human speech.”
Toward the conclusion of Bird Brains and Behavior, the writing transitions to a more accessible style than the largely academic prose that makes up most of the text. To round out their discussion of complex cognition, Striedter and Iwaniuk compare the task of analogizing brain function between birds and humans to that of humans and generative AI. The analysis ends quite abruptly, however, with the blankness of the chapter’s end staring back at readers who might simply wonder, “How?”
The final section focuses on the state of human-bird relations as it currently stands. Here, Bird Brains and Behavior comments intelligently on the ongoing saga of environmental issues with regard to the mutability of behavioral science in a changing world riven by catastrophic climate change and a slew of festering ecological degradations. Even so, the researcher in the discipline of avian neurobiology has much reason for optimism. Striedter and Iwaniuk are hopeful, noting that a suite of familiar neuro-imaging techniques are now being applied to understanding the avian brain. These include electroencephalography (EEG), structural and functional magnetic resonance imaging (MRI), and positron emission tomography (PET). This sphere of experimentation has spread its wings and looks forward to a long and fruitful flight path.
Matt Hanson is a freelance journalist and book critic from Massachusetts based in Istanbul since 2016. He has written about literature and the environment for various outlets including Jacobin, World Literature Today, Words Without Borders, Nonprofit Quarterly, and the International Center for Journalists.
