TITLE:  Supernavigators:  The Astounding New Science of How Animals Find Their Way

AUTHOR:  David Barrie

PUBLICATION DATE:  2019

FORMAT:  Hardcover

ISBN-13:  9781615195374

ALTERNATIVE TITLE:  Incredible Journeys:  Exploring the Wonders of Animal Navigation

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DESCRIPTION:

"In Supernavigators, award-winning author David Barrie takes us on a tour of the cutting-edge science of animal navigation, where scientists are unraveling how creatures as various as butterflies, birds, crustaceans, fish, reptiles, and even people find their way.

Weaving interviews with leading experts on animal behavior with the groundbreaking discoveries of Nobel Prize–winning neuroscientists, Barrie introduces astounding animals of every stripe: Dung beetles that steer by the light of the Milky Way. Ants and bees that navigate using patterns of light invisible to humans. Sea turtles, spiny lobsters, and moths that find their way using Earth’s magnetic field. Salmon that return to their birthplace by following their noses. Baleen whales that swim thousands of miles while holding a rock-steady course, and birds that can locate their nests on a tiny island after crisscrossing an ocean.

There’s a stunning diversity of animal navigators out there, often using senses and skills we humans don’t have access to ourselves. For the first time, Supernavigators reveals these wonders in a whole new light."

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REVIEW:

David Barrie has compiled an interesting and accessible survey of the studies done to elucidate the variety of techniques (and combinations thereof) used by organisms (everything from dung beetles, fish and birds, to humans and whales) to find their way about - both short range navigation and longer migrational navigation.  The chapter dealing with the effects of the built environment on other creatures, as well as the use of our new navigation technology is especially interesting.  The chapters are short and each one has an "epilogue" which is usually interesting, sometimes pithy, or just provides something to think about.  Some topics are covered more superficially than others, and I would have liked to have read more about the actual biological basis of these animals wayfinding ability, but none-the-less, a fascinating book with a somewhat erratic organisation.

UPDATE POSTS:

Chapters 1-6

Chapters 7-12

Chapters 13-17

Chapters 18-25

Chapters 26-27

TITLE:  Supernavigators:  The Astounding New Science of How Animals Find Their Way

AUTHOR:  David Barrie

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Chapters 26 and 27 deal with why navigation matters and how navigation has changed due to new technological innovations:  from learning the language of the Earth to using GPS and sattellites, and why this is not always such a good thing.  Barrie also discusses how human habitation and technology interferes with other animal's navigational abilities.

If you have absolutely horrendous navigational skills, even in areas you have lived in all your life, you may be suffering from “developmental topographical disorientation”.

 

"Asked how he went bankrupt, a character in one of Ernest Hemingway’s novels answers: “Gradually and then suddenly.” The loss of our navigational skills has happened in much the same way. It began, slowly, with the adoption of earlier, simpler technologies like the compass and sextant, but these did not relieve us of the need to pay close attention to the world around us and to use our wits.

The arrival of GPS has, by contrast, brought about an abrupt and fundamental change in our relationship with nature. Now we can fix our position and set a course without the slightest thought or effort—without so much as raising our eyes from our glowing screens. The gadgets that seem to have relieved us of a tiresome burden are not only enfeebling us but also distancing us from the natural world."

This last section provides food for thought, and thus concludes this rather interesting book.

TITLE:  Supernavigators:  The Astounding New Science of How Animals Find Their Way

AUTHOR:  David Barrie

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Chapters 18 to 25 deals with a variety of "map and compass" type navigation techniques.  Barrie differentiates between other-centered navigation and self-centered navigation. 

Self-centred navigation depends on how objects in the environment are related to that particular organism, such as taking note of prominant landmarks and remembering which direction "you" moved in i.e. the world revolves around "you".  Self-centered navigation depends on learning to recognize the landmarks that define a route, so that you can accurately retrace your steps.  Previous examples of self-centred navigation include the bogong moth, the desert ant and "dead reckoning".

Other-centered navigation depends on understanding how environmental objects or landmarks are geometrically related to each other. Maps provide this kind of information.  Barrie goes on to explain how one can orientate themselves in space using a map and compass.  

Barrie then takes a look if other non-human animals can use a type of "map and compass" navigation to find their way around.  These are particularly interesting chapters in which Barrie discusses the various experiemnts used to determine other-centred navigation in animals and the "discovery" of "magnetic maps" and "circadian clocks".

There is also a chapter devoted to how birds (and other animals) determine their longitude.  There is evidence that the “circadian clock” in mammals (based in a part of the brain called the hypothalamus) contains two types of neuron, one of which reacts immediately to a change in daylight hours, while the other takes up to six days to adjust.  These two clocks might just possibly enable mammals (and perhaps birds) to detect a change in longitude.  There is also evidence that organisms make use of the omnipresent geomagnetic field to determine where they are and where they are going.

Chapters 20 to 22 focus on sea turtle navigation:  how hatchlings find the ocean, how breeding females find their home beach and how the turtles navigate in the ocean.  The section on sea turtles is not as detailed as I would have liked.

Chapter 23 deals with the hunt to find the physiological sensors that allow animals to detect the earth’s magnetic field.  Hypotheses include magnetite bearing cells, the "light-dependent compass" dependent on cryptochrome molecules, and electromagnetic induction.

Chapter 24 and Chapter 25 are fascinating chapters in which Barrie discusses the role that the hippocampus has in making mental maps of an organism's surroundings.  This section is too complex to summarise, so I suggest reading those chapters.

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RECOMMENDED BOOKS:

~Voyage of the Turtle:  In Pursuit of the Earth's Last Dinosaur by Carl Safina

~What a Fish Knows:  The Inner Lives of Our Underwater Cousins by Jonathan Balcombe

TITLE:  Supernavigators:  The Astounding New Science of How Animals Find Their Way

AUTHOR:  David Barrie

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Chapter 13 involves navigation by sound. Echolocution, sonar, infrasound and just using ones ears is discussed.  I'm rather disappointed that the echolocution section wasn't dealt with in more detail.  The "Concorde effect" was a rather interesting section in which the mystery of the lost pigeons is solved.

 

"Fishermen in Ghana can apparently find fish by sticking an oar in the water. The flat blade acts like a directional antenna that collects their underwater grunts and whines; by putting his ear to the handle, the fisherman can determine roughly where the fish are."

Chapter 14 is a fairly interesting chapter that takes a look at how the Earth's magnetism effects the navigational abilities of species.  Lodestones, magnets, the geomagnetic field (its declination, inclination and intensity) are all discussed with an eye to how the aid us and other animals in navigating.

Chapter 15 focuses on elucidating how the Monarch butterfly navigates during it's extensive migration, while Chapter 16 deals with the migration of the Silver "Y" moth, and Chapter 17 deals with the Australian Bogong moth (and some interesting field experiences).

"One way of controlling the spread of invasive animals like these is to move them away from areas where they are causing trouble, but first you need to be sure they will then stay put—especially in view of the experience with Australian crocodile.

       So scientists captured pythons in the Everglades, implanted radio trackers in them (under anesthetic), and transported them in opaque, sealed containers to sites up to twenty-two miles away. Six of the snakes were released at these remote locations, while six others (the controls) were taken straight back to the places where they were captured, before being given their freedom.

      The radio tags on the pythons were monitored from light aircraft. To everyone’s surprise, the translocated pythons all headed for home, and five of them returned to within three miles of the places where they had been caught. They were more active and moved faster than the controls, and they clearly had a good idea of where they wanted to go. The controls, on the other hand, just moved around randomly.

     It seems unlikely that the homing pythons used DR, so perhaps they have some kind of map, based on magnetic, olfactory, or celestial cues. Behavior like this has never been seen before in a snake."

TITLE:  Supernavigators:  The Astounding New Science of How Animals Find Their Way

AUTHOR:  David Barrie

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Chapter 7:  Well, there is a bit of biographical waffling about one of the scientists...and how that scientist came to work on Tunisian desert ants in the middle of nowhere.  Apparently the ants' homing abilities did indeed depend partly on their sensitivity to polarized light (and other things).  Then there is also figuring out that the ants can measure distance.  The "ant odometer" is actually a thing!

The chapter had an interesting "epilogue":

"The estuarine crocodiles of Southeast Asia and Australasia are the world’s largest reptiles—and have the unpopular habit of eating unwary humans. They may give the appearance of being quite sedentary, but they can move fast over short distances and can travel hundreds of miles at a more modest pace.

In 2007, a fascinating study revealed that they are also remarkably good at finding their way home. Three adult males were captured and fitted with satellite trackers. They were then carried in slings under a helicopter to different release sites on the Cape York Peninsula in Queensland, Australia. After spending some time apparently thinking about what to do next, all three of them eventually headed off and returned to the exact places where they had been captured.

One of the crocodiles traveled 62 miles along the coast in fifteen days; another covered 32 miles in only five days. That was quite impressive, but nothing compared to what the third one did. It was transported right across the Cape York Peninsula from west to east—an overland distance of 78 miles. Obviously it could not retrace its journey, but it still managed to get home by paddling right around the northern end of the peninsula and down the other side. It covered a distance of 255 miles in just twenty days.

Nobody has any idea how these animals found their way home, but this experiment provided a valuable practical lesson: There is clearly little point in “translocating” crocodiles that pose a threat to people."

Chapter 8 is particularly interesting since it deals with various human navigational cultures "steering by the sky" throughout history (and prehistory) and goes into a bit of detail on how they did this.  I enjoyed this chapter - something different from the bugs and birds.

Chapter 9 is a brief survey of studies dealing with long migrations that birds make seasonally.    Chapters 11 and 12 describe various animals (moths, salmon, birds etc) that navigate using smell to find their way home or to potential mates.  These two chapters are also fairly interesting.

Chapter 10 describes attempts by scientists to determine how dung beetles can roll their balls in straight lines (hat wearing dung beeltes was part of one experiment), along with all sorts of other interesting dung beetle trivia.  This is also an incredibly fascinating chapter.