BEARING - Maphead - page 16

when the term “ cognitive map ” was first coined in 1940, it wasn't used to refer to humans
at all but to the surprising maze-solving abilities of lab rats.
It's well known that animals can perform navigational feats that make even the canniest
human trackers look, in comparison, like blindfolded four-year-olds swinging cluelessly at
a birthday party piñata. Baby loggerhead sea turtles, immediately after hatching in Flor-
ida, embark straightaway on an eight-thousand-mile circuit of the North Atlantic, getting
asfarastheAfrican coast beforereturninghomeadecade later.Theydoitalone,theystart
when they're less than two inches long, and they don't get lost. Scientists have trans-loc-
ated black bears hundreds of miles from their home in the forests of Minnesota and seen
the majority quickly return. In 1953, a British ornithologist named R. M. Lockley heard
that a friend, the noted American clarinetist Rosario Mazzeo, was flying home to Boston
the following day. Lockley seized the opportunity to give Mazzeo two Manx shearwa-
ters, seabirds whose homing abilities he had been studying. “In the evening, I enplaned for
America with the birds under my seat,” Mazzeo later wrote his friend. “Only one survived
the flight.” (Note to self: Don't let a woodwind player watch my pets next time I'm out
of town.) He released the surviving bird from the east end of Boston's Logan International
Airport and watched as it flew straight out to sea. Less than two weeks later, the bird reap-
peared in its British burrow. The shocked scientist, who hadn't heard from Mazzeo since
his departure, assumed that he'd been forced to release the bird somewhere in Britain, but
thatverydayhisletterarrivedfromtheUnitedStates,describingtheshearwater'sbriefBo-
ston visit. The bird had made it back home ahead of the mail, traversing 3,200 miles in just
twelve and a half days.
Not all feats of spatial memory are long-distance migrations straight out of Walt Disney
movies. The frillfin goby is a small tropical fish that's usually found in rocky pools along
the Atlantic shore. When threatened in a tide pool, either by a predator or by falling water
levels, it has a remarkable defense mechanism: it escapes by shooting itself up into the air,
like James Bond from an Aston Martin ejector seat. If you ever had a suicidal goldfish as
a child, you know that accurate jumping isn't always a fish specialty, but the goby always
jumps straight into another (safer) pool. Sometimes it makes up to six consecutive pool
hops until it arrives in open water. Obviously the fish can't see out of its own pool, so how
does it make these leaps of faith? It plans ahead. It takes advantage of every high tide to
explore its surroundingssoit knows—andremembers—where the safest spotsare likely to
be once the tide goes out.
But just because an animal can perform an impressive bit of way-finding doesn't mean
it'srelyingonasophisticatedcognitivemap.Theclarinetist'sshearwater,forexample,was
crossing territory it had never seen before, the North Atlantic. It was obviously flying on
instinct, not a mental map from past experience. We now know that many migrating birds
rely on the position of the sun as a compass, as well as the sights and even smells of habit-
ats along the way. Baby turtles are sensitive to tiny variations in the earth's magnetic field;