Writer, adventurer and three-time Guinness World Record holder Dan Buettner recently spent some time studying the ecologically challenged Galápagos Islands. Here, from his journal, are some ongoing impressions.

rom a distance, the beach in Gardner Bay, on the southernmost island of the Galápagos, looks like it could be any one of a number of American beaches.

The long white strip of sand is littered with hundreds of overweight sunbathers and their kids. Some frolic in the water, others snuggle with their mates, while others just snooze and catch rays. It's a scene you might witness on a hot day in Santa Monica, Atlantic City or Fort Lauderdale.

The difference is that none of the unshapely bodies here are human.

By 10 a.m. we had dropped anchor in Gardner Bay. After a breakfast of cornflakes and kiwi fruit, we boarded a small dingy ("panga"} and motored into shore. The sunbathers on the beach turned out to be Galápagos sea lions – a subspecies of the California sea lions – all warming up in the morning sun.

Determined to observe these lumbering beasts on my own terms, I took a long walk along the coast, past some lava boulders, to a spot where 21 sea lions had staked out a patch of sand.

I walked to within 10 feet of a sleeping bull and sat down. Nothing happened. I crept closer, to within five feet. Nothing. Finally, I nudged up until I sat less than three feet in front of the bull. He opened his eye and flung up his head. Startled, I leaped back.

For a long moment, we stared at each other. Bull sea lions have been known to bite intruders. Since their mouths are so full of bacteria, the bite almost always infects the surrounding flesh and takes a long time to heal. Moreover, this animal must have weighed 500 pounds – it was like confronting an angry Sumo wrestler.

But this bull wasn't in the mood to attack.

This sea lion's face looked amazingly like a dog's face. He had a long snout, wispy whiskers and a cute, rounded forehead that made me want to pet him. Unlike a dog, he had tiny ears set far back on his head that looked like chewed cigar butts.

But what most caught my attention were his eyes, which were big and brown and regarded me with supreme indifference. He plopped his head down into the sand and resumed his nap. He couldn't care less about me or that I had stopped by to visit him.

I began to feel mildly insulted.

I'm so used to animals running, flying or swimming away from me that I was startled to have an animal just ignore me. For all he knows, I could be an animal catcher from the zoo. If he isn't careful, he could end up spending the rest of his life balancing a beach ball on his nose for five year olds.

Dan Buettner (Visit his Web site.)

The presence of people in the Galápagos is but a blink of an eye in the island's five-million-year history. But in the brief 300 years that humans have occupied the Galápagos, we've managed to cause the extinction of eight of the 14 mammal species here. Another three species are endangered.

Part of the sea lions' charm is that they haven't learned to fear humans. You can sit down right next to them and watch them nap.

Is this a good thing, or could their charm spell their doom?