So we rode all around the park until quite late talking and philosophizing quite a lot and I finally told him that I thought, after all, that bird life was the highest form of civilization. So Gerry calls me his little thinker and I really would not be surprised if all of my thoughts will give him quite a few ideas for his novels. Because Gerry says he has never seen a girl of my personal appearance with so many brains.
“Gentlemen Prefer Blondes” Anita Loos
Maybe bird life is not the highest form of civilization. But a recent book, The Parrot in the Mirror: How Evolving to be Like Birds Makes Us Human, makes the case that primates in general, and humans in particular, are special in ways that show convergent evolution with birds. To wit:
Vision: Mammals in the Mesozoic Era were largely nocturnal. With the great dinosaur extinction, some mammals moved into diurnal niches. Primates take this further than most. Like birds, primates are highly visually oriented. Birds have exceptional color vision, with four types of color-sensitive cone cells in their retinas. Most mammals have just two. But Old World monkeys and apes (and you, unless you are colorblind) have three types of cones. On the other hand, birds and primates are less attuned to smells than most mammals.
Longevity: Birds are long-lived relative to mammals. At any given size, a bird is likely to live maybe twice as long as a typical mammal. (Something to consider when choosing a pet.) Primates are also longer lived than most mammals, and human beings long-lived even among primates. Birds can afford to slow down their life histories and senesce more slowly, because being able to fly puts them at lower risk from predators. Primates too live life in the slow lane, relying on brains and sociality to cut down on the predation and other extrinsic mortality that push many mammals to live fast and die young.
Brains: Birds have relatively small, i.e. light-weight, brains, as part of being lightly built for flight. But their small brains pack in lots of smaller neurons compared a similar size mammal brain.
[C]ompared with mammals, very small birds, with similarly small brains, will have many more neurons than similarly sized mammals. Small songbirds can weigh in at barely a tenth the weight of a common mouse, but sport more than double the number of neurons. Meanwhile, some of the heaviest bird brains, which are found in the macaws, the big, colourful South American parrots, weigh in at perhaps 20–25 grammes. This is a bit bigger than the brain of a common European rabbit. Yet while the rabbit has about half a billion neurons in its whole body, the macaw can have over three billion in its brain alone, a number more in line with much larger giraffes and baboons There are really only four types of animal that get into the billions of neurons: whales, large mammals such as elephants and seals, primates, and brainy birds (parrots and crows).
https://www.amazon.com/Parrot-Mirror-evolving-birds-makes/dp/019884610X/
Pair bonds. Many birds, especially passerines (perching birds, including songbirds = most bird species) pair up, with males and females cooperating to care for offspring. There’s only so much nutrition you can pack into an egg, so baby birds are often pretty helpless, and need two parents to take care of them. Human infants too are pretty helpless; there’s only so big a fetus can get before birth. And children, growing slowly, take a long time to become independent. So human mothers too commonly have to enlist helpers in providing for their offspring.
Vocal communication. Among birds, parrots, hummingbirds, and songbirds show exceptional vocal learning abilities. (Among mammals, the closest nonhuman exemplars are cetaceans.) In birds, vocal learning may happen during juvenile sensitive periods (in humans: think about learning the local accent in childhood) or may be more open-ended (in humans: think about adding to your vocabulary throughout life). Bird vocalizations can be socially transmitted, and different communities can develop distinctive dialects.
And even among birds, parrots are really exceptional. The Parrot in the Mirror gives them a whole chapter to themselves. Parrots are a pinnacle in the evolution of intelligence.
Logarithmic History 