'Greatest Nature Photographs of All Time' Featured in Earth Day Auction

"A group of Australian sea lions relax and frolic in a sea grass meadow near Little Hopkins Island South Australia. They are a curious species that nuzzle the lens and playfully pull on fin and mask straps. While I was photographing them the leader of the group stood straight up and looked around and then swam straight and fast for the beach with the entire group following. The sea was still and quiet and something told us that maybe we should leave too and we climbed into our boat just as a great white shark came into view. The Australian sea lion is one of the rarest and most endangered pinnipeds in the world."- David Doubilet

Split Rock and Cloud, Eastern Sierra, California, 1976 Galen Rowell

Galen Rowell (1940-2002) was a master of incorporating fleeting qualities of natural light in compelling compositions. He saw this splendidly illuminated cirrus cloud floating quickly on the wind while climbing one evening in the Buttermilk region of California's Eastern Sierra Nevada. Rather than simply capturing an image of the cloud out of context with the place, Galen wished to incorporate a sense of the boulder-strewn granite landscape around him. He imagined a composition that paired the cloud with a strongly graphic silhouette, and traversed the rugged landscape to find a foreground subject in a suitable position to photograph against the sky while the cloud passed overhead. He waited only thirty seconds after setting up his tripod-mounted Nikon before the cloud floated through the perfect position.

Polar Dance

For centuries, polar bears have gathered along the Western shores of Hudson Bay during late October and early November waiting for the bay to freeze. Here at Cape Churchill the land extends far out into the bay and is one of the first places the bay begins to freeze. When the ice grows solid, the polar bears move out onto the ice where they will spend the winter hunting for their main diet of ringed and bearded seals. While the pregnant females leave the bay and head inland thirty-five to forty miles. There they will dig dens, and the young will be born in December and January. Cape Churchill is the largest gathering of polar bears on earth. Here the relatively solitary bears come together and socialize waiting for the temperatures to drop and the ice to freeze. As the winter storm approached the cape, during near whiteout conditions, two adult polar bears test each other's strength in what is known as play fighting. From the time polar bears come out of their dens in March and April, cubs, like most animals, play fight. Male polar bears continue to play fight into adult hood. It not only keeps them fit and establishes a hierarchy, but to any viewer it is obviously something the bears enjoy. Polar bears are my favorite mammal to photograph, and this image titled "Polar Dance" with its almost human-like gestures of dance and the mood created by the blowing snow is my most favorite image I've made. -Tom Mangelsen

Morning Mist, Rock Island Bend, Franklin River, Southwest Tasmania, Australia

Photograph Peter Dombrovskis copyright Liz Dombrovskis

This iconic photograph was instrumental in allowing the rivers to run free. It was first published in "The Australian Newspaper" prior to the 1983 Australian Federal Elections with the slogan: "Could you vote for a party that would destroy this?" There was public outrage...The rivers still run free.

Petrified Sand Dunes and Reflection, Paria Canyon - Vermilion Cliffs Wilderness, Arizona

Pulitzer-prize winning photojournalist and landscape photographer Jack Dykinga made this photograph as part of a campaign to create National Monuments in both the Paria Canyon and Escalante Canyon drainages. He had tried on six separate occasions to make this image following seasonal rains, dissatisfied each time with the quality of the reflections in the standing water. His final effort paid off after driving south from Salt Lake City and arriving near Paria Canyon around midnight. Dykinga camped at the mouth of one of the side canyons and began hiking in around 3:30am in order to arrive on location in time for dawn and calm water. The Abrams publishing house rewarded the effort in Dykinga's book Stone Canyons of the Colorado Plateau (1996), creating a cover free of any type because publisher Lou Gotlieb so loved the image. Following the successful creation of the Grand Staircase-Escalante National Monument and Vermilion Cliffs National Monument, Interior Secretary Bruce Babbitt sent Dykinga a letter of thanks, noting the book's help in raising public awareness of these special places.

Tortoises at Dawn, Galapagos Islands, 1984. Giant tortoises in pond, Geochelone elephantopus, Alcedo Volcano, Galapagos Islands

"The Galápagos Islands provide a window on time. In a geologic sense, the islands are young, yet they appear ancient. The largest animals native to this archipelago are giant tortoises, which can live for more than a century. These are the creatures that provided Darwin with the flash of imagination that led to his theory of evolution. Immutable as the tortoises seem, they were utterly vulnerable to the buccaneers and whalers who took them by the thousands in the last two centuries. But one population eluded them. Inside the Alcedo volcano on Isabela Island, an earlier era lingers. This caldera is sealed off from the outside world by steep lava slopes that rise to 3,860 feet on the equator. It was not until 1965 that an Ecuadorian biologist found a way down inside and discovered a world where giant tortoises roamed in primordial abundance. This group had presumably never seen humans. They hadn't seen many more when I entered the time capsule of the caldera. For one memorable week, I lived among the tortoises of Alcedo. Photography one morning was one of those precious experiences where I could be part of a scene rather than a distant observer. The tortoises were resting in a pond as soft mist mingled with sulfur steam from nearby fumaroles and dust from an erupting volcano to the west, and I was able to create an image that evokes the era when reptiles dominated life on land."- Frans Lanting.

Water Lilies, Nymphaea nouchali, Okavango Delta, Botswana

"One of the greatest challenges in photography to me is to define a personal point of view. During my work in Botswana's Okavango Delta, I looked for ways to capture the essence of this great wetland and my own response to the wonder of it. The Okavango covers thousands of square miles, but it is really just a thin sheet of water stretched across the sands of the Kalahari. The delta's water lilies drew me in because they symbolize life made possible by water in this dry land. I photographed lilies covering lakes and giving shelter to an array of animal life, but I was searching for something more lyrical. One day I looked down in a clear lagoon and noticed how a patch of lilies was anchored in desert sand. An idea took hold. I plunged into the swamp. Actually, I slipped in. Quietly. Crocodiles abound here. While an assistant stood guard in a small boat, I sank to the bottom with a camera encased in a bubble-shaped underwater housing. I held my breath on each dive, which allowed for less than a minute at the bottom. It took many attempts and the better part of a day for the image to become refined. I was intrigued by the sinuous curves of the lily stems. In an interesting reversal of the maxim about magic light peaking around sunrise and sunset, underwater photography conditions get better towards high noon, when light penetrates farther into the depths. By the time I had figured out solutions to the technical problems of this shot, the midday sun backlit the lily pads suspended at the water's surface. From the bottom of the swamp I saw that the lilies told a larger story, about the anomaly of water in the desert. In one sense the margin for life was exactly the distance from the lilies above my head to my toes buried in the sand. But my perspective was of the exuberance, not the limits, of life. The water was only a few feet deep, but the lilies reached for the sky."- Frans Lanting

Twilight of the Giants, Botswana 1989

African elephants at twilight, Loxodonta africana, Chobe National Park, Botswana

"During the year I spent living in the Okavango Delta of Botswana, I worked at night for periods of time, waking up at sunset to follow animals through the hours of darkness. I often started the evening at a favorite water hole where I hunkered down by the edge and made myself a fixture in the landscape. Elephants moved around me in the waning light like shadowy forms. One evening a herd of bulls gathered across the water from me, rising above their reflections under an October moon, in a primeval scene of ancient Africa. Elephants move seasonally in and out of the Okavango and across northern Botswana, ranging over huge territories to find what they need to survive. In an earlier era, elephant trails crisscrossed the entire African continent. If you fly over the land, you see elephant trails, some abandoned, others still followed. Older elephants pass on their knowledge to younger generations, and the matriarchs and old bulls know of places that are used as refuges in times of drought or stress--places that may be visited only once in a lifetime. What maps are carried in the minds of elephants? Their epic wanderings over northern Botswana may be part of larger ecological patterns that go beyond rainy and dry seasons, years of drought and decades of plenty. What elephants know lies on the fringes of our understanding, like the indistinct forms of animals in the night, moving just beyond the edge of human vision. The existence of huge free-roaming herds of elephants in Botswana is a symbol for both the nature of this landscape and for the human decisions that must be made about the fate of wild places and wildlife both here and elsewhere on earth. How we balance those interests will be the legacy of our time, the path we leave on the land." - Frans Lanting