"If birds built their nests according to a genetic template, you would expect all birds to build their nests the same way each time. However this was not the case," added Dr Walsh.

“如果这些鸟根据一种遗传模板来建起自己的巢穴，你就会料想到，所有的鸟每次都以同样的方式筑巢，但情况并非如此，”沃尔什博士补充说。