Section 2.2. Human Wayfinding in Natural Habitats

2.2. Human Wayfinding in Natural Habitats

What single characteristic distinguishes humans from all other animals? Our labels reflect attempts to answer this question. Homo habilis or "handy man" suggests the importance of tool use. Homo erectus or "upright man" emphasizes hands-free, heads-up, bipedal locomotion. And, Homo sapiens or "thinking man" invokes the value of intelligence and the capacity for language. In truth, we have much in common with our fellow creatures, including identical chunks of DNA and a common evolutionary heritage dating back four billion years. And for most of our history, we've wandered the same natural habitats without the benefit of compass, map, or signpost. It's no surprise that animals and humans share similar navigation skills and behaviors.

Unfortunately, we know very little about the two million year "prehistory" of human wayfinding. Prior to the invention of written language 5,500 years ago, we are left only with crumbling skulls and educated guesses. Our understanding flows primarily from modern studies in anthropology, archaeology, psychology, biology, and neuroscience. For example, it's a safe bet that early humans were dependent on the five basic senses. Though we talk about our "sense of direction," research has shown no convincing indication it exists. Lacking the polarized vision of ants and the magnetoreceptors of turtles, we have had to rely heavily on an awareness of our own movements (path integration) and a meticulous attention to environmental clues.

Today, much of this tacit knowledge, this ability to "read" the natural environment has been lost. Most of us can't set course by the position of the sun or the vegetation and moisture patterns on north and south facing slopes. Consequently, we underestimate the richness of available cues and marvel at the mysterious skills of our ancestors, such as the Polynesians who navigated open ocean voyages without instruments. In tiny canoes, they explored the vastness of the world's oceans, discovering such uninhabited and disparate islands as Samoa, Tonga, Tahiti, Hawaii, and New Zealand. Employing an ancient art of navigation, these seafaring explorers relied solely on careful observation of natural signs to reckon direction and location. The sun, moon, stars, and planets served as broad navigational framework. Ocean swells, winds, landmarks, and seamarks such as schools of fish, flocks of birds, and clusters of driftwood provided more localized clues.

Ethnographers often provide a glimpse into the past by studying indigenous, living societies that have preserved their ancient culture and tradition. In 1936, the anthropologist Raymond Firth wrote:

The island of Tikopia is an example of another sort of system which is neither universal, egocentric, nor directed toward a base point, but is tied to a particular edge in the landscape. The island is small enough so that one is rarely out of sight or sound of the sea, and the islanders use the expressions inland or seaward for all kinds of spatial reference.... Firth reports overhearing one man say to another: "There is a spot of mud on your seaward cheek."^[*]

^[*] Quoted in The Image of the City by Kevin Lynch. MIT Press (1960), p. 129.

The use of prominent landmarks such as a mountain as the primary means of orientation has been observed in many societies, but only a very small island would support the particular system employed by the Tikopians . Unique environments produce unique solutions. And since necessity is the mother of invention, harsh environments produce creative solutions. Nowhere is this more evident than in the Songlines of the Aboriginal Australians . For thousands of years, these people navigated their rough and unforgiving land by inventing, memorizing and following an intricate series of songs that identified critical paths and landmarks. These oral road maps told how the features of the desert landscape were formed and named during the period of creation known as the Dreamtime. These songs were cultural and spiritual treasures. They also led you to the next waterhole.

What did the first signs look like? Broken branches on the hunting paths of prehistoric man? Piles of rocks guiding nomadic tribes to their next camp? Maybe even earlier than thatclaw marks on tree bark, or scent messages, the keys for which have been lost long ago.

Romedi Passini

Of course, while most people were doing things the hard way, early "handy man" geeks were learning to hack the environment. The earliest examples were most likely real, physical hacks: marks on bark indicating a path through the woods. Why rely on natural landmarks when you can create your own? Just don't use breadcrumbs. As Hansel and Gretel would testify, the birds will eat them. Speaking of hungry birds, Norwegian seafaring hackers learned to bring ravens on long voyages. When they thought land was near, the sailors released the birds, which had been deliberately starved. The ravenous ravens often headed "as the crow flies " directly toward land.

Most of the written history of wayfinding concerns the invention or adaptation of tools to support nautical exploration. The limited availability of landmarks and seamarks combined with the high cost of getting lost to provide a powerful incentive to be inventive. Consider the following solutions employed by sailors over the centuries:

Lighthouse

The earliest recorded lighthouses were bonfires. They served as highly visible landmarks for sailors. The lighthouse of Alexandria, built around 270 B.C., was named one of the seven wonders of the ancient world. A mirror reflected sunlight during the day and a fire guided sailors at night. At 400 feet, it was among the tallest manmade structures on earth.

Compass

The Chinese used a magnetic device for land navigation called a "point-south carriage" as early as the third millennium B.C. In the West, the first mention of a compass comes in 1187 when englishman Alexander Neckham writes that "sailors use a magnetic needle which swings on a point and shows the direction of the north when the weather is overcast." Early compasses were very crude. A navigator would rub an iron needle against a piece of magnetic iron ore known as a "lodestone." He'd then place the needle in a piece of straw and float it in a bowl of water where it would point to the magnetic north pole. Many sailors believed the compass operated by black magic. Thanks to superstition and the inaccuracy caused by magnetic variation, the compass was not widely used until the 1700s.

Chip log

Over the years, sailors used a variety of dead-reckoning methods to compute distance traveled at sea. One method involved the use of an 18 inch chip of wood tied to a long rope with knots every 47 feet 3 inches. The chip was thrown over the stern (back end), and the number of knots were counted as they passed overboard until an hourglass filled with 30 seconds worth of sand had expired. The faster the ship was sailing, the more knots played out. Five knots was equivalent to five nautical miles per hour. We still refer to miles per hour on the water as "knots."

Sextant

Preceded by the Arabian kamal and the medieval astrolabe, the sextant constituted a breakthrough in global positioning, enabling sailors to compute their latitude (north-south position) to within a nautical mile or two by measuring the angle of heavenly bodies (i.e., sun, moon, planets, stars) above a horizontal line of reference, and then consulting an almanac prepared by astronomers that forecast the position of those heavenly bodies hour by hour many years into the future.

Chronometer

To determine longitude (east-west position) with sufficient precision, it became evident that a more accurate time-keeping device was needed. Sailors knew that for every 15 degrees traveled eastward, the local time moves ahead one hour. So, if they knew the time at two points on earth, they could calculate longitude based on the difference between them. They could measure the local time by observing the sun, but the trick was keeping track of time at a reference point such as Greenwich, England (the prime meridian). Pendulum clocks didn't work well at sea. Solving this problem was considered so important that countries began to offer prizes. In 1764, John Harrison won the British prize by inventing a seagoing chronometer accurate to one-tenth of a second per day. A few years later, Captain James Cook used Harrison's chronometer to circumnavigate the globe.