Fear Takes a Holiday : Animals of Galapagos Islands Appear to Lack That Instinct
If ever there was a land on the other side of the looking glass, this is it--a stark volcanic outpost in the Pacific where the ground is mostly rock and many animals seem to lack the instinct of fear.
Here a person can still stare down a perching hawk, nearly eye to eye, walk a path through 100 dozing iguanas, or step within inches of nesting flightless cormorants. Few animals bother to budge.
But scientists are divided over why the animals greet humans without ruffling feathers or seeking safer ground.
Some say that in a place with only two seasons--dry and wet--where equatorial heat often soars well above 100 degrees, animal inhabitants try to expend as little energy as possible. And many animals’ eggs would cook if left unattended in the hot sun.
But other scientists tend toward a more provocative argument, saying Galapagos creatures apparently forgot how to fear, their ancestors leaving the instinct of “fight or flight” behind when they swam, flew or floated here to escape prehistoric predators on the South American mainland.
In this archipelago of 13 islands, 600 miles off the Ecuadorean coast--often called a living laboratory of evolution--these scientists say it is the relative isolation that helped suppress the instinct and only a reckless presence of humans can bring it back.
“Fear is a very basic instinct in all animals, be they person or lizard,” said biologist Graham Watkins, who studied the special flora and fauna of the Galapagos Islands at the Charles Darwin Research Station on the island of Santa Cruz.
“It’s not that the instinct failed to make an imprint in these animals, it’s just that many of them haven’t had a need to invoke it in the way an African gazelle would, or even people who live in cities and who have a fear of crime.
“They lived here for hundreds of thousands of years before man ever arrived, in a paradise of animals, so to speak, where they all could exist in relative harmony and where, for the most part, one animal wasn’t another’s dinner.”
This tameness, he said, has been observed in other areas of relative isolation, primarily remote islands where birds or reptiles were usually the first and, hence, predominant colonizers.
“The Falkland Islands are an example of this phenomenon,” he said. “The colonizers there are very similar in behavior, and the same is true of those in the South Georgia Islands near Antarctica.
“You can walk among the albatross colonies there and not a single bird will move.”
On a hike over the rocky terrain of the island of Espanola, in the Galapagos’ southeast, he points to colonies of blue-footed boobies, sea birds with feet as distinctive as their habit of nesting on the ground.
This ancient nesting style could have meant extinction in an environment filled with predators, Watkins said.
Nearby, amid low-growing brush, a cousin, the masked white booby, ambles near its chick as humans walk within inches. A hawk perches on a boulder nearby.
The hawk is not a predator to either of the boobies, birds with rather formidable-looking beaks that narrow to a point. The boobies got their names from a mispronunciation of their Spanish name, bobo .
The fact that the birds and other animals of these islands show relatively few signs of fearing humans could have something to do with the unusual geology and equatorial positioning of the island group, as some scientists suggest.
The archipelago as a whole is a surrealistic picture come to life.
Acre upon acre of land has little or no fresh water; the barren white trees called palo santo grow in volcanic ash, and inland saltwater ponds are striking for their stillness and tinge of green caused by algae.
Any one of the 13 species of finches--made famous in evolutionary studies by 19th-Century naturalist Charles Darwin--perch within inches of people without obvious fear.
Colonies of black and orange sea iguanas, nearly camouflaged on slabs of black volcanic rock, do not scatter when people walk among them.
Pairs of albatrosses and 2-foot-tall cormorants sit nearly motionless, unfazed by human presence.
California biologist Gary Robinson, a curator at the Santa Barbara Museum of Natural History, who leads walking tours of the islands, said it is speculated that the instinct of fear left the sea birds and reptiles gradually.
“One way of looking at it is that over time, they felt there was nothing to worry about. They could make their nests on the ground and not have to be concerned about the animals around them.
“They tend to respond to humans the way they respond to other animals. Most of the animals--the flightless cormorants are a good example--evolved in these islands without any major predators.
“This is their environment, and for many of them, there’s nothing to worry about.”
But the Galapagos Islands are not without problems.
Currently, 10,000 people live here, most of them poor and residing in ramshackle houses on the islands of Floreana, San Cristobol and Santa Cruz.
Red dirt roads on these islands lead to small harbors where scientists and thousands of tourists arrive annually to observe the plant and animal life unique to the archipelago.
Many residents try to eke out a living from the tourist trade by hawking goods made from teeth, bones, skin, feathers and other parts of animals, unaware of any potential harm to wildlife.
“They don’t think they are doing anything bad,” Watkins said, “They think these things are nice and are valuable enough to sell.”
About 18,000 tourists travel to the archipelago annually, according to Ecuadorean government figures. All of the wildlife areas are under control of the Ecuadorean national park system, whose officials try to enforce strict rules.
“The government was concerned when the park was established (in the early 1970s) that moving people through the colonies would cause (the animals) to show signs of fear. That hasn’t been the case for the most part,” Robinson said.
But Watkins, a resident of the islands, is concerned because fear is an instinct that can easily be provoked.
“The mechanisms for fear are there. They can learn that they have to move away from people.”
He said iguanas on the island of San Cristobol, the most heavily populated with humans, dash for cover when people approach.
Killing of Iguanas
When people began moving to the island, he said, they began killing iguanas.
While sea birds essentially have been left unharmed over the centuries, giant tortoise populations have been devastated by human encroachment.
“They couldn’t have gotten away from people even if they wanted to,” Watkins said of the beasts that weigh as much as 600 pounds. Three of 14 subspecies of tortoises are now extinct, a direct result of human abuses that occurred for more than 300 years.
Ever since Darwin’s famous trip to the Galapagos aboard the Beagle in 1835, the archipelago has been of keen interest to biologists and others seeking to study with unusual closeness the behavior of creatures on the islands.
“Darwin himself conducted an experiment of sorts to test the apparent lack of fear among the animals,” Robinson said. “He grabbed a marine iguana from a sunning area and threw it into the ocean. The iguana came out of the water and right back to the same area where it had been sunning.”
Robinson said Darwin inferred from the test “that iguanas had more to fear in the water than they did on land,” an unusual conclusion given that algae-eating iguanas depend on the sea for survival.
In an essay, the 19th-Century naturalist compared the apparent lack of fear among birds in the archipelago to a natural fear of people in England’s geese.
The geese were conditioned by centuries of capture to take flight whenever people approached, Darwin wrote.
But the obvious vulnerability of birds in the Galapagos, and the delight that 19th-Century sailors took in killing targets that wouldn’t move, caused Darwin to wonder if in time the fear instinct would pervade the islands’ species.
“Despite the last 200 years of man being there and persecuting the animals, they are still very tame, perhaps a little less tame than when Darwin made his observations, and himself knocked down a hawk with the butt of a gun,” Robinson said.
The islands are populated with thousands of birds--frigate birds, gulls, flamingos and others, many of them descendants of species now extinct on the mainland.
Other animal colonists include lizards, rodents, fur seals, marine and land iguanas, giant tortoises and the only tropics-dwelling penguins in the world.
“They either swam, flew or floated to get here,” Watkins said, speculating that an ancient urge to flee predators was so great that ancestors of the islands’ species took their chances at sea.
Scientists generally believe that giant tortoises probably floated to the Galapagos Islands, aided by their own buoyancy, while lizard eggs may have arrived on driftwood pushed westward from the mainland by prevailing winds and the Humboldt current.
Watkins said man’s presence has been most devastating to the islands’ tortoises, whose populations were decimated by people and the rats that accompanied them.
Black rats brought on ships were so destructive to the islands’ ecology, as a whole, that they led to the extinction of an endemic Galapagos rat.
Watkins contends, however, if introduced predators stay under control, it is possible for the animal colonizers of the islands to live without fear for centuries to come.