Magdalena Island's Magellanic penguins

On this bright, blustery Christmas morning on Magdalena Island, the residents are well-dressed, and fish is on the menu. Festive couples sing and sashay around.

Getting ready to join the scene, passengers from the expedition cruise ship Mare Australis look like party-crashers in yellow rubber rain suits and bright orange life vests.

The island's scents, sounds, and sights beckon. The chorus of hoots and honks rivals the horn-blowing crowd at a European soccer match. Little fleets of sea creatures, darting and diving, ferry out to meet the Zodiac boats. Small dolphins? No, penguins heading to sea for a Christmas dinner of fish, squid, and krill.

Magdalena is a nature reserve and summer home to more than 60,000 Magellanic penguin families. These knee-high birds, with their signature white facial and torso stripes, far outnumber us. Thanks to conservation measures - such as a local ban on commercial fishing and careful monitoring of visitors - this seabird colony is thriving.

It turns out penguins can fly, but water is their element. Their flipper wings and torpedo shape make them fast and graceful swimmers. Magellanic penguins spend half the year at sea. One of 17 penguin varieties, they prefer the relatively warm sub-Antarctic waters of the Falklands, southern Chile, and Argentina. Every September they return to rookeries such as Magdalena Island to breed, raise their young, and molt.

Males arrive first to reclaim last year's burrow in the sand. Then, dancing and clacking beaks, lifelong mates reunite, and females lay a pair of eggs. The parents take turns brooding on the nest and feeding in the open ocean, which is why so much traffic bustles in and out.

We disembark on the pebbly beach of what seems to be a small kingdom. Clearly this is not one of those wildlife safaris where we tread softly, hoping to catch a glimpse of animals. We're more likely to trip over the inhabitants, which are everywhere. Penguins dot the windswept grassy hummocks. Little crowds stand around the shore, dive off the rocks, wiggle belly-up in the surf, and recline belly-down drying in the sun.

Our guides have explained that Magellanic penguins are naturally shy, but that their sharp beaks can inflict wounds. We have been schooled in proper etiquette: Keep quiet, don't run, never touch, and maintain a few yards' distance. Evidently nobody briefed the penguins, which seem not the least bit worried about the giant neon aliens waddling about their domain.

A small unobtrusive fence makes all the difference. Constructed of stakes and cables, it marks a 1,970-yard-long walkway up the coast to a lighthouse, which serves as a manned ranger station from September until March each year. While allowing us a full view, the fence also prevents us from inadvertently collapsing the cavelike burrows that mine the terrain. The birds, confident that we're corralled on our side, have no reason to fear, and scuttle back and forth as they please. In fact, some come right up close and stare, even nipping at our pants out of curiosity.

Like Gulliver among the Lilliputians, I amble up the path in the wind, trying to take it all in. The residents people-watch from the entranceways of their burrows. Inside, shaggy gray chicks doze, eyes half-mast, like contented kittens.

Sand spurts from a nearby hole, which is being refurbished. Although Magdalena Island's sparse vegetation provides little cover, its deep layers of soft soil are perfect for digging. Snug burrows offer protection from harsh weather and avian predators. Hungry gulls, petrels, and falconlike skuas would happily nosh on penguin chicks or exposed eggs.

One parent must stay vigilant from incubation until the fledglings are self- sufficient (nine to 17 weeks), while the other forages for food at sea.

There, other dangers lurk: sea lions, leopard seals, and orcas. So, apart from being snazzy-looking, the penguins' formal attire provides camouflage. Seen from above, the black back disappears against the dark ocean depths; from below, the bright white front blends with the sunlit water. Tuxes are no defense against humans, who pose the greatest danger, however. In centuries past, sailors harvested penguins for eggs, meat, and fat, rendered into oil.

The penguin population took another hit in the l980s and '90s, when commercial fishing competed for its food supply. Pollution from the offshore oil and gas industry remains a continuing problem. Many seabirds die every year due to accidental oil spillage and the intentional discharge of oily ballast from tankers.

But this breeding site flourishes. In many burrows two strapping youngsters huddle, a sign that food abounds. Chile's government designated Magdalena Island as a national nature reserve in 1983, and established a no-fishing zone in the Magellan Strait. The Corporacion Nacional Forestal (CONAF) monitors the birds, and also the tourists, who now number about 10,000 per year.

With a resounding hoooonk, males proclaim their territories - big brown feet planted, beaks in the air, sound bubbling up from their chests. In the commotion, a mother disappears down a hole, clutching dried grass for the nest.

Amid screaming gulls, we climb back into the Zodiacs, leaving only bootprints in the mud. Seldom is a wildlife encounter as satisfying as in this place. Magdalena Island's infrastructure is minimal: a lighthouse and a simple fence. The accessibility it provides to wild seabirds feels like a wonderful gift. These structures, I realize, also suggest a promise: to be vigilant and stay within bounds. Perhaps our willingness to do so is the best Christmas gift we can offer in return.

• Magdalena Island is located in the Magellan Strait, 20 nautical miles north of the town of Punta Arenas, Chile. During peak breeding season (December to February), the landing craft Melinka departs on Tuesdays, Thursdays, and Saturdays at 4 p.m. from the Tres Puentes terminal in Punta Arenas, returning at 9:30 p.m. Contact Turismo Comapa, phone 011-56 61 414300; fax 011-56 61 414361; website www.comapa.cl.

• The expedition cruise ships Mare Australis and Via Australis have four- and seven-day itineraries between Ushuaia, Argentina, and Punta Arenas, Chile, stopping at various locations including Magdalena Island. Contact Australis Cruises, 4014 Chase Ave., Suite 202, Miami Beach, FL 33140; phone 1-877-678-3772; fax (305) 534-9276; website: www.australis.com.