“Extreme behavior in birds is more likely in Australia than anywhere else.” Australian birds occupy more ecological niches than birds anywhere on earth. They tend to be longer lived and more intelligent than birds on other continents. Also, Australia is where some fundamental aspects of bird being were born. Like song.

​想去澳洲看鸟
#TheBirdWay #读书

birds pack more brain cells into a smaller space. When the team counted the number of neurons in the brains of twenty-eight different bird species ranging in size from the pint-size zebra finch to the six-foot-tall emu, they found that birds have higher neuron counts in their small brains than do mammals or even primates of similar brain size. Neurons in bird brains are much smaller, more numerous, and more densely packed than those in mammalian and primate brains. This tight arrangement of neurons makes for efficient high-speed sensory and nervous systems. In other words, say the researchers, bird brains have the potential to provide much higher cognitive clout per pound than do mammalian brains.

鸟类的视锥细胞也是 densely packed, 好厉害呀​​
https://www.quantamagazine.org/hyperuniformity-found-in-birds-math-and-physics-20160712/

Ornithological vision has been skewed not just by the hemispheric bias of researchers but also by their gender and gender bias. Until quite recently, most ornithologists were men, and research tended to focus on what male birds were up to; the part played by female birds in the life histories of their species, from female ornamental traits to breeding systems, was often downplayed or ignored.

这点是我没想到的，怎么男科学家对雌性鸟类不感兴趣吗？男人研究男人是为了造福自己我还能理解，怎么研究别的物种的时候也要带入自己吗。。

For centuries, it was thought that male songbirds alone used song as they used fancy plumage and elaborate tails, to attract females and compete with rival males. The female role was to listen and choose and, in so doing, exert influence through sexual selection, driving the evolution of elaborate singing by preferring males with ever more melodious and complex songs. This was considered a classic example of the power of sexual selection to generate extreme sex differences in brain and behavior. Instances of female song were largely dismissed as atypical—rare exceptions or the outcome of hormonal abnormalities.
All that changed when the international team of researchers led by Karan Odom surveyed the occurrence of female song in 1,141 species from all over the world. The team suspected that male-only song was not the whole story by any stretch. Most songbird species live in tropical regions, which have been less studied. And female song is more common in Australia and surrounding areas, where songbirds originated. There, it’s a much more egalitarian setup. Sure enough, the results of the study, published in 2014, showed that female song occurs in more than two-thirds of surveyed songbird species and families—and that it’s structurally similar to male songs (long and complex) and used for similar purposes. In the songs of male and female superb starlings of eastern Africa, for instance, there’s no difference in the structure or the number of motifs that each sex sings. Both sexes in this highly social species sing all year long and may do so to signal identity and establish rank within their groups. The study made it clear: Birdsong is not just a male thing. And elaborate song did not evolve just through sexual selection—females choosing males for their vocal prowess—but through the broader process of social selection: both sexes competing for food, nest sites, territories, and mates.