蜂鸟（2）

这只小巧玲珑的鸟魅力足够感动严肃的维多利亚女王 —— 可是蜂鸟的魅力比人类眼睛能察觉的更多。蜂鸟是最小的鸟类。最小的叫雄性吸蜜蜂鸟，体重少于2公克，半茶匙糖差不多一样。18天的孵育以后，它从埃及豆一样小的蛋子孵出。长大了以后，它的翼展差不多3厘米。本体是蓝色的，交配期之际它嗓子的羽毛变成红色的；它的羽毛是彩虹色的，如果光明改变，羽毛的颜色也改变。

361的已经发现的蜂鸟物种之中，很多有这样的彩虹色，包括：红尾彗星蜂鸟，拥有很长、叉形的金红尾巴；还有白喉蜂鸟，胸脯上有鲜明粉色的部分，脖子后面的毛羽摊开像一条围巾。蜂鸟是一个灿烂的物种，它们也互相看比人类看蜂鸟更好看。大多数鸟的视网膜能看出人类看不到的紫外颜色；比方说，蜂鸟能看 ‘紫外黄色’ 对它们，这个眼色和一般的黄色像人类看的蓝色和绿色一样不同。今年初，耶鲁大学的研究报告“蜂鸟羽毛中的‘鸟类能看’的颜色比所有别鸟物种羽毛的颜色数量更多。” 世界上没有更有色的鸟物种。

Their Lilliputian （意思：非常小） beauty is enough to stir the most stolid queen – but the hummingbird is far more fine than human eyes can see. Hummingbirds are the smallest living bird. The most miniature of these miniatures, the male bee hummingbird, weighs less than two grams, about as much as half a teaspoonful of sugar. Hatched after eighteen days of incubation from an egg the size of a chickpea, his wings grow to barely three centimetres across. He is blue in body, with a gorget (the feathers at the throat) that turns red during the mating season; his plumage is iridescent, changing colour in changing light.

Many of the 361 known species of hummingbird have a similar iridescence: among them, the male red-tailed comet, with its long, forked, golden-red tail; and the wine-throated hummingbird, with its hot pink bib, the hind feathers of which flare outwards from the neck like a cravat. They are a shining race, and they see one another more vividly than we do. The majority of birds have cones in their retina that allow them to perceive a spectrum of ultraviolet colours invisible to us; hummingbirds see an ultra-violet yellow, for instance, which is as different from the yellow we see as green is from blue. A study from Yale earlier this year reported that ‘the diversity of bird-visible colours in hummingbird plumages exceeds the known diversity of colours found in the plumages of all other bird species combined.’ There is no bird species in the world more colourful.