2023年经济学人 山雀在筑巢时会“追赶潮流”（在线收听）

One day in March 2021 Dr.Wild, Dr.Aplin and their collaborators deployed five RFID-enabled dispensers loaded with wool rather than food.

2021年3月的一天，威尔德博士、阿普林博士和协作人员部署了五台配有射频识别技术的取食器，但取食器中装载的是羊毛，而不是食物。

Each contained strands of two colors - either orange and pink or blue and purple - but all were rigged to dispense only one of these.

每个取食器都有两种颜色的羊毛——橙色和粉色，或蓝色和紫色——但所有取食器都经过了配置，只提供其中一种颜色的羊毛。

This remained so until at least one local nest was seen to include wool from a dispenser.

直到研究人员观察到至少有一个鸟巢是用取食器里的羊毛筑成的。

At that moment, the other colour was made available, too.

在那之后，另一种颜色的羊毛也会开放使用。

As a control, Dr.Wild and Dr.Aplin set up, in a separate area, four further wool-dispensers, each of which provided two colors from the get-go.

作为对照，威尔德博士和阿普林博士在一个独立区域设置了四个“取羊毛器”，并且两种颜色的羊毛取用不受限制。

Of 68 tits' nests built that season in the experimental areas, 26 included wool from a dispenser.

在那个季节，试验区的山雀筑造的68个巢中，有26个使用了取食器里的羊毛。

Of these, 18 were constructed after both colors had become available from all dispensers.

这其中有18个是在所有取食器都提供两种颜色的羊毛之后建造的。

Even so, ten of that 18 included only the colour of wool first chosen by a nestbuilder.

即便如此，在这18个鸟巢中，有10个只用了最早筑巢的山雀选择的颜色。

By contrast, all eight wool-bearing nests in the control zone contained a mixture of colors - a statistically significant difference.

相比之下，控制区用羊毛筑造的所有八个巢穴都用了多种颜色的羊毛——从统计学上来说，这两者具有显著差异。

Tits, then, do seem to be "on trend" when it comes to nest-building materials.

因此，在筑巢材料上来说，山雀似乎确实在“追赶潮流”。

Why that should happen remains obscure.

发生这种情况的原因不明。

Dr.Wild and Dr.Aplin suspect the trendsetters are older birds, and that evolution favors younger ones copying their elders since those elders have evidently survived what fortune has to throw at a tit.

威尔德博士和阿普林博士怀疑，引领潮流的是较为年长的鸟类，由于生物学的进化，幼小的鸟类倾向于模仿它们的长辈，因为这些长辈显然命运捉弄下的幸存者。

Williams's original work, though, suggests such initial choices are arbitrary.

然而，威廉姆斯最初的研究表明，鸟类一开始的选择是随机的。

A bit like those of the leaders of human fashions.

就像人类的时尚领袖一样。