animals,  Mayhem Series,  Research,  The life of a writer,  Wildlife

Why Don’t Wild Animals Get Lost?

Northern lights show magnetic fieldHave you ever wondered how birds follow their migration route or how sea turtles find their way back to their birthplace? After all, sea turtles spend twelve years at sea before they return to dry land. Why don’t they get lost? What do they perceive that we miss?

A lot, as it turns out.

We know the molten material inside Mother Earth rotates, right? Otherwise, life on Earth wouldn’t have any protection from harmful radiation generated by the sun. This rotation produces a massive magnetic field that extends into space and provides reliable navigation for animals to orient themselves. Many species use this magnetic field—bees, whales, bears, worms, crows (all birds, but Poe wouldn’t be pleased if I lumped his People together with the others), sea turtles, lobsters, mole rats, butterflies, dolphins, elephants, salmon, and wolves, to name a few—any animal that needs to navigate through their environment.

The intensity of Earth’s magnetic field varies.

It’s weakest at the equator and strongest at the poles. Also, the angle between the field lines and the Earth changes with latitude. An animal migrating northwards from the equator will encounter steeper and steeper inclination angles on its route.

The list of animals with a magnetic sense—called magnetoreception—has grown to include species in every vertebrate category, as well as certain insects and crustaceans. Some may use it for orientation, such as blind mole rats. Others like salmon, spiny lobsters, and thrush nightingales may use it for migration and homing, in combination with other sensory cues.

Humans rely heavily on our senses to tell us about our environment.

In Restless Mayhem, Shawnee learned humans possess more than the usual five senses—touch, smell, taste, hearing, and sight—after a nasty run-in with a cougar.

  • Proprioception is the sense that tells us where, say, our left leg is in space and time.
  • Our vestibular sense alerts us to the direction our bodies are moving in relation to gravity.
  • Thermoception is our sense of temperature. Though it’s often linked to touch, it’s distinctive with its own set of receptors.
  • Pain is the fourth additional sense. On the surface, it may appear as an extension to touch, but our sense of pain is far more complex.

The human body has three different types of pain receptors:

  1. Mechanical receptors alert us to physical pain
  2. Temperature pain receptors alert us to extreme heat and cold
  3. The body triggers chemical receptors like inflammation, which causes tooth-achy type pain

What we don’t have is magnetoreception, the ability to sense Earth’s magnetic field.

Or do we? Hold that thought. The answer may surprise you.

Magnetic Field Alignment

cows use magentic field for alignmentIf you gaze into an open field, you may notice most cows or deer face the same direction when they feed. Scientists determined that cows and deer tend to face north when they eat or rest.

Over time, scientists conducted this research by using field observations, measuring deer beds in snow, and through satellite images from Google Earth.

These animals have a compass in their brain. The behavior is called magnetic alignment, the spontaneous orientation of the main axis of an organism with respect to the lines of Earth’s magnetic field. Factors like wind and the angle of the sun had little significance on how the animals stood, according to research publishing in the National Academy of Sciences.

Instead, their heads rotated to the north like the needles of a compass. Though these animals may not be aware of what north means, some part of their brain tells them this is the direction they should face.

Animals don’t quite point toward the north pole. Instead, they face slightly off in the direction of magnetic north, as this position — known as magnetic declination — changes across the face of the planet. In turn, so do the wildlife.

The first reports of magnetic field alignment were found in the 1960s, but it wasn’t until 2008 that we discovered mammals do this as well.

For example, researchers studied red foxes, who hunt small animals like rodents, show a behavior known as “mousing.”

foxes use magnetic field to find preyAnyone who watches nature documentaries has seen this many times. The fox listens for a mouse as they prowl closer. Once they narrow in, the fox jumps high in the air then nosedives into the soil, and usually comes out with prey in its mouth. The fox is using magnetoreception! Interestingly, foxes prefer to jump in a northeastern direction. Why? No idea. LOL It’s one of the mysteries of nature.

Researchers theorize the magnetic field alignment in foxes help them estimate distance to their prey.

Foxes also have what’s called radical pair-forming photopigments in their eyes. Stayed tuned for a future post about different types of animal eyes—I’m fascinated by them! Anyway, radical pair-forming photopigments allow foxes to see the magnetic field as a pattern on top of what they’re already viewing. So, picture like a laser grid superimposed over another image. Pretty cool, right?

Wolves use Earth’s magnetic field like a compass to help remember vital places and territories. By measuring the strength of the magnetic field, they can pinpoint where they are. Lost wolves also use it to find their way back to the den. This detection ability is so dead-on accurate, it’s as reliable as a compass.

Using the magnetic field like a compass answers another question I had, but not enough to satisfy me.

Crows and other birds use magnetic field for navigation A country murder’s territory can span multiple acres. How do they know where one territory ends, and another begins? Also, how do migrating birds find their way home?

Since I wasn’t happy with the wolf explanation, I dug deeper.

All birds use Earth’s magnetic field for navigation, but don’t merely sense it—they can see it! The shadows they visualize indicate north, south, east, west, giving them a built-in compass. Amazing, right?

Can humans sense the magnetic field?

Research published in Nature (2022) found that we share similar abilities with our mammalian cousins. We just don’t know how to use it… yet.

In Other News…

The Poe PenExciting surprise for my newsletter subscribers. My friend and Kill Zone blogmate, Steve Hooley MD, is a master woodworker (he’s also an author who writes YA). Steve created the first ever “Poe Pen” for me to pass on to one lucky reader each month.

The giveaways were supposed to start at the end of July, but I have so much fun writing my Mayhem Series that time slips away. Now that I’ve finished my next eco-thriller, the first giveaway will have three lucky winners! Every month thereafter will have one.

The wood dates back to 1850 (“1850 Antebellum Cherry”) and the rings are burned into the pen by wrapping copper wire halfway around the pen while the pen is turning, creating friction, and thus heat. They represent crow talons (Crow Talons Publishing), as though a crow picked up the pen. Love it! The crow “Poe” he branded into the wood, so it’ll never come off.

Not only do these pens write like a dream — nice and smooth, with black ink — but the weight and shape of it in your hand is sheer perfection. Those with arthritic fingers like me will notice its genius design right away. I can honestly say it’s the best pen I’ve ever owned.

If you want to join the giveaway, you can do so here.

*By joining the giveaway, you’ll be subscribing to my newsletter.

Sue Coletta is an award-winning crime writer and an active member of Mystery Writers of America, Sisters in Crime, and International Thriller Writers. Feedspot and Expertido.org named her Murder Blog as “Best 100 Crime Blogs on the Net.” She also blogs on the Kill Zone (Writer's Digest "101 Best Websites for Writers"), Writers Helping Writers, and StoryEmpire. Sue lives with her husband in the Lakes Region of New Hampshire. Her backlist includes psychological thrillers, the Mayhem Series (books 1-3) and Grafton County Series, and true crime/narrative nonfiction. Now, she exclusively writes eco-thrillers, Mayhem Series (books 4-9 and continuing). Sue's appeared on the Emmy award-winning true crime series, Storm of Suspicion, and three episodes of A Time to Kill on Investigation Discovery. When she's not writing, she loves spending time with her murder of crows, who live free but come when called by name. And nature feeds her soul.

14 Comments

  • D. Wallace Peach

    That was fascinating, Sue. I didn’t know any of this, and I’m impressed with your research. I’ve written two books that include shapeshifters and researched the differences in vision between humans and a variety of animals. The science is mesmerizing, and including the details and differences in our writing makes the stories richer. I definitely noticed that in your Mayhem series. A fun post.

    • Sue Coletta

      Thank you, Diana! I’m mesmerized by animal eyes, too. Aww, thank you. I love adding these details to my books.

  • sherry fundin

    Fabulous post. You always share interesting information and I can hardly wait for the post on eyes. I have a thing for book covers with eyes, but oddly, my first facial feature I really notice is teeth. LOL The pens are awesome. I too have arthritis in my hands. Because of that, most of the time I highlight in my ereader over taking notes on paper, like I used to. I’m crossing my fingers, toes….and eyes…for the win. LOL
    sherry @ fundinmental

    • Sue Coletta

      Same, Sherry. I notice teeth first, but I’m fascinated by eyes. All the different types of animal eyes are even more intriguing. 😉

      Good luck!!!

  • Garry Rodgers

    Fascinating piece, Sue. You’ve done a pile of research for this. Re: salmon. I have a friend who is an oceanographer who told me that Pacific salmon do navigate in saltwater by using the magnetic field, but when they get close to the home freshwater source they were hatched in they begin to use their sense of smell as each stream has it’s own independent odor that is imprinted into the fish when it began life as a fry. Makes sense to me, but what I can grip is how Monarch butterflies navigate over generations – somehow they pass on directions through DNA or some factor we don’t understand. As for me, out in the boat, the best navigation invention ever is the GPS electronic chart system 🙂

    • Sue Coletta

      Thanks for adding to the discussion, Garry! It’s fascinating to think how each stream has its own odor. Makes sense, though, right? So many animals rely on their sense of smell. Navigation is built-into Monarch butterflies DNA? *faints* There’s so much we have left to learn.

  • Margot Kinberg

    This is so interesting, Sue! It aligns with what I read once (forget where – sorry!) about dogs If I remember what I read correctly, dogs tend to face the same direction when they hunch over to take care of business. I noticed that with my dogs, and I wonder if it’s the same explanation. Even if I’m wrong, I think there’s a lot about natural forces (like magnetic direction) that we don’t quite understand yet.

    • Sue Coletta

      You could be right, Margot! Since dogs are descendants of wolves, I’m sure they use magnetic direction. And yes, I agree, we’ve only scratched the surface of animals’ amazing superpowers!