Life is full of tales of dogs’ remarkable homing abilities: from the movies, to books, to real-life examples such as Bobbie the Wonder Dog, who traveled 2,800 miles to reunite with his family. According to new research published in eLife, a dog's navigation isn’t just led by their nose and heart — but by Earth’s geomagnetic fields. 

A team of researchers let dogs do what they do best: run to their heart’s content, then return to their favorite human. Scientists set a couple dozen dogs loose in the woods over 600 times — rigged with GPS collars and cameras — and mapped their journeys out and back.

Dogs use a variety of navigation styles on their return trip, researchers found. Over half of the dogs “tracked,” opting to follow the same path outward and homeward, while about one-third “scouted,” blazing a new trail on their way back. 

The “scouts” took seemingly haphazard routes, but their journeys shared an interesting common feature. They all began with a brief “compass run” — a short dash along the north-south geomagnetic axis. 

This sprint didn’t last long — about 65 feet or so — but it was consistent across the tests. The amount of sun and the wind’s direction didn’t alter the pattern, ruling out the hypothesis that sight or smell were at play. Dogs’ breed, sex, size, and familiarity with the location didn’t have an effect either.

What’s up with this north-south oriented dash? It could signify how dogs calibrate their inner navigation system, researchers suggest. They posit it’s a canine orienteering starting point — dogs' way of comparing their mental map with Earth’s geomagnetic fields.

If this all sounds far-fetched, consider the mounting evidence for canines’ magnetic sensitivities. Dogs possess a light-sensing molecule called cryptochrome 1, associated with magnetic sensing abilities. Canines even prefer to poop and mark their territory along a north-south axis.

It’s likely dogs lean on other senses to navigate, including that remarkable nose. But their sensory universe might be more multidimensional than we can fathom -- rippling with odors that tell stories, and magnetic fields that tug them home.