Wednesday, May 19, 2010

Some people study zugunruhe, the urge in migratory animals to move. When they're trapped and unable to go anywhere we can watch them, notice the disruption in their sleeping habits and how anxious they get just around dusk, measure the changes in their endocrine controls and what it is in their bodies that tells them where to go and how to get there.

You can fake zugunruhe by simulating long days, tricking brains into thinking that time is moving in different ways inside than it is outside. Our brains don't know both at once, of course, so the trapped fakely long days are what's real, forever, or at least until they end. They think that the more days a creature is stricken with zugunruhe, the longer their habitual migration might be. You'll have the longing to move for many more days if you're going across the world or to the moon or all the way under the water than if you're just going downstate. For example.

For a long time they thought that only species with active migratory patterns felt the longing, the endocromatic urge to run until it's too dark to see, for days and weeks and months. But now they have started really looking, and have noticed the restlessness even in species that seem perfectly content to stay where they are. The feeling is just as precisely timed for these animals, too, but they have evolved to think around it and stay put. It's still there, though, somewhere, and if they ever need to move again their brains will remember how, and where to go. They can all get somewhere else, once they realize that they need to.

No comments: