动物产生鲜艳的颜色是否有代谢代价?

这是一个非常好的问题，你完全正确，动物用色素来吸引配偶。这就是它的主要内容。这些分子的制造成本很高。更不用说你在捕食者面前看起来更明显了。这是一个叫杰弗里·希尔的人研究过的问题。他来自阿拉巴马大学。他观察了使用类胡萝卜素生长出黄色、橙色和红色彩色羽毛的家雀。和戴夫之前说的很像。他所做的就是用这种颜料喂一群家雀。他给其中一半的鸟喂了很多食物，所以它们很好，很快乐，过得很好。 The other half he restricted their diets, which wasn't very nice. Basically he wanted to know what the difference was when they did and didn't have enough food to eat. As you might imagine, the ones that didn't get enough food were much more drab than the ones that had lots of food who grew lots of night, shiny colourful feathers. That's a really good way of showing to us that yes, producing pigments is expensive in food and if you haven't got enough food to do that then you tend to not be able to produce such brightly coloured feathers.