American Robin 自然英语

We’veall heard about the “early bird” getting the “worm.” We know it as sound adviceabout initiative and timely action. And we can almost see that robin leaningback and tugging that recalcitrant worm out of the ground. Research shows,however, that birds dining early and heavily may lower their life expectancy. Astudy of three North American woodland bird species found that sociallydominant birds stay lean during the day and then stoke up when it’s mostimportant- later in the day, before a cold night. At night, birds avoidhypothermia by metabolizing fat. And by staying lean through most of the day,dominant birds are more agile in avoiding predators.
Subordinatebirds have to look for food whenever and wherever they can find it, and carryfat on their bodies to hedge against unpredictable rations. Dominant birds,which can push subordinates off food, can choose when they eat and so lessentheir odds of being eaten themselves.
Therefore,at least in the woodland bird’s world, the revised moral might read: “Get the wormlate in the day- you’ll sleep better and live longer.”