One researcher told me how his entire career had been devoted to the sensory biology of birds and, apart from once being asked to write a chapter for an encyclopaedia of bird biology, had received relatively little recognition. On retirement he had burned all his papers, and then - to his simultaneous dismay and delight - I started asking him about his research.

惨惨
#BirdSense #读书

Amazingly, we train ourselves to ‘reverse’ the inverse image on our retinas. In a famous experiment conducted in 1961, Dr Irwin Moon wore image-inverting spectacles that effectively turned the world upside down. At first he found it horribly disorientating, but after eight days of wearing the spectacles Dr Moon had adjusted and ‘saw’ the world the right way up again. To prove it, he drove his motorbike and took his plane for a spin – without mishap. Moon’s extreme experiment provided irrefutable evidence that we ‘see’ with our brain rather than with our eyes.

哇，我以前有听说过因为眼睛的成像是上下颠倒的，所以婴儿刚出生的时候看到的世界是反的，后来才调整过来的，原来同样的过程也可以在成人身上实现！大脑好神奇！

Type 2 includes birds like ducks and the woodcock, whose eyes are high up on the sides of the head. They don’t have a great forward view and most don’t need to see their bill tip because they rely on other senses when feeding, but they do have panoramic vision, above and behind – helping them detect potential predators. Interestingly, the views from each eye barely overlap, so they probably see two separate images.

如果两只眼睛看到的图片没有重叠的话，那不是就很难推测物体的深度吗​​还是说它们要求不高所以边运动边推测也可以…
我觉得很有意思的是，如果是像人的眼睛那样两只都在前面，那么前行的时候靠一只眼睛推测深度就不精确；但鸭子眼睛在两边，所以前行的时候几乎就是和视线垂直，两边的深度可以较好地计算…（有机器人是这样做的吗？）但前方到底是怎样呢…只能靠别的感官吗…

这本书里说到鸟类的 retina 不像脊椎动物的那样分布有血管，而是单独由一个叫 pecten 的器官提供，这样看东西不用隔着血管会更清晰。
于是我上网想查查看 pecten 长什么样，结果查到维基的图上有画血管，那是不是画错了啊？按照我的理解所有的血管都在 pecten 里？维基说“大大减少 retina 里血管的数量”，而我查到的别的来源都说是 no blood vessels…虽然“减少到零”也勉强能算“大大减少”吧…

ps. Retina 的中文是“视网膜”，但既然鸟类的 retina 里没有血管，那叫“网”就不合适了。
pps. Fovea 的中文是“中央窝”，但鸟类有两个 fovea，那也不能叫中央了吧。

If you have observed captive birds of prey, you will see that they often move their head from side to side or up and down as they watch you approach. They do this because they are alternating your image on their two foveas, the shallow one for close up, the deep one for distance.

咦我只注意过猫头鹰歪脑袋！它们不能转眼珠，所以就转脑袋。
不过恍惚也有印象鸟类的脑袋转得特别快。。观鸟不够多，下次出门带望远镜（还想搞个好的镜头​​

some birds of paradise in New Guinea and manakins in South America actually create their own sun spot on the forest floor by pruning adjacent trees. It was once thought that this ‘gardening’ was to minimise the risk of predation, but as our understanding of avian vision improved, it became clear that the birds were manipulating the background colour to maximise the visual contrast of their plumage and the overall effectiveness of their sexual displays.

哇，自己给自己造舞台

#BirdSense 是男性鸟类学家十年前写的，还提到雄性鸟类通过展示自己的性魅力来吸引雌性。这种视角我觉得就比较男。比较新的书 #TheBirdWay （女作者著）里倒是有提过这是因为男性科学家长期以来对雌性鸟类的忽视。实际上对于很多鸟类这是一个双向选择。比较喜欢后者提到这种问题的视角，但是那本书的写作手法我实在太不喜欢了，读不下去，好可惜。。（要不我再试试​​
#BirdSense 里还有一段：

Darwin’s contemporaries simply couldn’t imagine that females (human or non-human) were smart enough to make such informed choices.

...couldn’t imagine that females were smart enough...我无语凝噎

我真的很难想象人类为什么会在研究鸟类的时候那么 arrogant。。如果我去研究鸟类，肯定会急切地想要知道它们在哪些地方比人类要厉害，哪些地方跟人类不同，怎么可能 we have been incredibly reluctant to accept that birds, or any animals, see the world differently from ourselves. 或者 However good we (arrogantly) think our colour vision is 啊。。现在科学届还是这个态度吗？我感觉我从小读动物科普的时候接触到的态度就是“这个好神奇”“那个好厉害”，没有这些个书里提到的那种 arrogance 吧

在人类身上发现什么稀奇玩意儿，我的想法：咦动物会不会也类似，赶紧看一看。
科学家：for a century or so was thought to be unique to humans.

...why

有的鸟类睡觉的时候可以 literally keep an eye open ​

总是看到说某些鸟的一生能够绕地球飞多少多少圈多么厉害，但既然鸟类可以边飞边睡觉的话，那好像也没有特别厉害？？
人类可以边坐飞机边睡觉

The closest we can come to imagining what it is like to process information as rapidly as a hummingbird or a hawk is the sensation of time slowing down that occurs during a near-death experience. Over the years I have had a few near-death experiences while doing fieldwork, and I imagine many readers will have had, like me, the same sensation during traffic accidents. As you slam on the brakes and slide inexorably towards another vehicle or a tree, it is as if your brain is taking in every detail and each second is drawn out until it feels ten times longer than it really is.

所以电影里的慢镜头也是有真实依据的？？我还没有过濒死体验…

It cannot be doubted that the faculty of hearing is highly developed in birds, not only the mere perception of sound, but also the power of distinguishing or understanding pitch, notes and melodies, or music.

可以对鸟弹琴​​