How Do Animals Find Their Way Home Without GPS?

Animals travel hundreds of kilometers without GPS, but how? Understanding the earth's magnetic field might be the ultimate travel tip.

Humans, as a species, have a lousy sense of direction. Relative to some animals that migrate thousands of miles -- birds, whales, antelope -- we're hopeless, really. The other species don't mention it much, but they're just being polite.

A batch of new scientific studies sheds light on exactly how some animals are able to navigate so successfully. Julien Huguet has the goods in today's DNews report.

We've known for a while that many critters can directly sense the Earth's magnetic field and use it to calibrate a kind of internal compass. A recent report in the journal Nature uncovered some intriguing specifics. It seems that dogs, foxes, wolves and some primates have a particular kind of protein in their eyes that's sensitive to magnetism. That's right: protein in the eyeballs. Didn't see that one coming.

In a related study, a team of biologists and mathematicians teamed up to figure out the incredibly efficient navigation system of the monarch butterfly. The monarch really is king of the road. Its annual migration from Canada to Mexico -- by far the longest distance traveled by any insect -- has intrigued biologists for decades.

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Researchers recently concluded a lengthy study in which they recorded data directly from neurons in the butterflies' antennae and eyes. The conclusion: Monarchs plot their impossibly efficient migration routes by tracking the precise position of the sun in the sky. The insect then matches that positional data with timekeeping "clock neurons" to determine the optimal route.

This kind of signal matching suggests that monarch butterflies have biological "circuitry" that's much more complex than we previously imagined. The research team even developed a model circuit to recreate the internal compass, and they hope to someday build a robotic butterfly that navigates by the sun.

Humans lack the ability to navigate so precisely, whether by magnetism or light. Some scientists think it's possible that we used to have such abilities, and maybe still do, somewhere deep in the brain. But over millions of years of evolution, we've lost any functional access to internal navigation.

Still, that may not be a bad thing. As Julian explains in the video, our terrible sense of direction has prompted us to explore new territories as a species, both literally and metaphorically. Instead of following the same migratory routes year after year, we pioneered our way into new environments.

At some point in our evolution we may have lost our intrinsic ability to navigate, but we compensated with new ways of thinking. We learned to track the stars, make compasses, and eventually invent Google Maps. And that's pretty good, right? Not magnetic-protein-in-the-eyeballs-good, but pretty good.

-- Glenn McDonald

Learn More:

Science Alert: How dogs find their way home (without a GPS)

New Scientist: Why humans can't navigate out of a paper bag

The Atlantic: All Can Be Lost: The Risk of Putting Our Knowledge in the Hands of Machines