Green turtles were mating in the water in front of us when our Zodiac pulled up to Bartolome,  a pile of lava covering an area less than half the size of New York’s Central Park, just off Santiago Island in the Galapagos.

Green turtles mating. Photo by David Braun.

Bartolome is a breeding and nesting ground for the turtles. It’s also a favorite stop for visitors to the Galapagos because of its fantastic geology, an energetic climb up 376 wooden steps to a commanding view from the summit of the islet’s main volcanic cone, and spectacular snorkeling with sharks and rays in the clear water around postcard-famous Pinnacle Rock.

This is the eighth post in my account of a ten-day exploration of the Galapagos, on board the National Geographic Endeavour. In my previous post I wrote about climbing Dragon Hill in search of giant iguanas. I was on the Lindblad-National Geographic Expedition as the National Geographic expert. (See all the Galapagos Expedition posts here.)

Every island we visited on our tour was unique in both appearance and its assemblage of species. But none stood apart from the others so much as Bartolome. It’s a relatively young island, expelled from the sea by forces deep in the Earth that created a mound of gnarled and twisted lava frozen in the tubes and spatter cones of a volcanic eruption more than a million years ago.

Some travelers have observed that Bartolome looks like a landscape on the moon, bereft of plants and life. Others think it looks more like Mars, perhaps because red is a predominant color of the rock. But it’s certainly not without life. Everywhere I looked I saw evidence of the opportunism and tenacity of Earth’s species. It was another fascinating lesson of how life takes hold and adapts to the tough conditions of the Galapagos.

NASA image courtesy of MODIS.

Climbing the Volcano

Galapagos National Park authorities somehow managed to construct a boardwalk to allow visitors to walk comfortably and safely up and along the steep sides of the volcano. It was made to protect the island from erosion caused by people climbing the cone, according to our guides. But much of the ground was covered in pebbles and sand at angles so steep in places that it would have been impossible to walk on it without slipping and sliding.

In the foreground, a lava cactus, one of the first "pioneer" plants to occupy the barren landscape of a volcanic island. Photo by David Braun

Members of our party cast shadows on the lava terrain of Bartolome islet, Galapagos. Photo by David Braun.

This does look as if it could be on Mars. Photo by David Braun

It’s true that there are hundreds of steps and nearly 400 feet to make the ascent from beach to summit, but our guides led us at a stately pace, at least for those of us in the group that opted for a pace that allowed stops to enjoy the views along the way. Faster climbers like Anthony, my son, elected to join the first group that reached the summit with minimal stops. For those who selected the more leisurely pace, there were platforms every few hundred yards where we could admire and make pictures of the view and catch our breath. It’s a thoughtful system that caters for people of all levels of fitness.

Photo of feeding frenzy  out at sea by David Braun.

“Who knows what that sound is,” our naturalist asked when we got to the first platform. “The wind,” I ventured. Wrong. The dull roar was coming from the ocean below us, from a giant patch of what looked like boiling water, apparently a signature of the chaos caused by a feeding frenzy of predators driving fish to the surface. Looking down the lava slopes colored pink and yellow, the distant churning sea made me think how the entire scene was primordial. The Galapagos was like this for thousands of centuries before a human set foot on the place.

A famous view of Pinnacle Rock and the beaches of Bartolome. The big island of Santiago is in the background. Photo by David Braun.

Photo by David Braun

Photo by David Braun

Pinnacle Rock

High on the summit of the volcano, we had a terrific view of one of the most famous landscapes of the Galapagos: Pinnacle Rock and back-to-back golden crescent beaches separated by a narrow neck of land. Pinnacle, our naturalist explained to us, got its spear-tip shape from both erosion and the U.S. Air Force. The strange structure is made of tuff, compressed volcanic material that erodes readily under the natural effects of wind and rain. During World War II the U.S. built an airfield on Santiago Island, next to Bartolome, as part of a ring of defenses around the Panama Canal, which Japan might have targeted to disrupt Allied supply lines. The airmen used Pinnacle Rock as target practice, adding to Mother Nature’s sculpture of the formation. No live ordinance was used, our guide assured us. The rock was targeted with bombs filled with sand. That was reassuring to hear, for we were later to go snorkeling around Pinnacle Rock.

Photo of Pinnacle Rock beach by David Braun.

Pinnacle Rock and its two adjacent beaches were a dramatic foreground to the sweep of Santiago Island across the sea. From our perch on the volcano, we could also enjoy the 360-degree panorama of the ancient eruption and the titanic forces that had shaped the Earth around us.

Photo by David Braun

Gobs of lava. Photo by David Braun

Bartolome's lava is brightly colored. Photo by David Braun

The Red Rock Crab Known as Sally Lightfoot

We descended to the beach and admired the Sally Lightfoot crabs swarming over the glistening rocks.

Sally Lightfoots “are very beautiful, with clear brilliant colors, red and blues and warm browns,” according to quotes attributed to John Steinbeck in his book The Log from the Sea of Cortez. “Everyone who has seen them has been delighted with them. The very name they are called by reflects the delight of the name. These little crabs, with brilliant cloisonné carapaces, walk on their tiptoes, They have remarkable eyes and an extremely fast reaction time…If you walk slowly, they move slowly ahead of you in droves. If you hurry, they hurry. When you plunge at them, they seem to disappear in a puff of blue smoke—at any rate, they disappear.”

Photo by David Braun

Photo by David Braun

Photo by David Braun

Steinbeck made his observations about the Sallys he saw on the shores of the Sea of Cortez. According to the Encyclopedia of Life website about the crab, the species is commonly found on the rocky shores of the Pacific Ocean from North America to Peru, and of course, the Galapagos. I don’t think there was a single island we went to in the archipelago where we did not see these magnificent crustaceans, which, fully grown, are about the size of a splayed human hand. As Steinbeck noted, they are wary and easily spooked. Trying to sneak up on them to make a memorable photo resulted in their disappearing act described by Steinbeck. The Sally Lightfoot reputation is that it is almost impossible to catch one — although an attempt to do so would not have been permitted in terms of Galapagos National Park regulations.

Grapsus grapsus gets its common name, Sally Lightfoot, from its quick mobility, according to a paper about the crab by By Christopher Davis. “It runs with extraordinary speed and agility along the upright sides of rocks and has the uncanny ability to hide away in crevices to escape predation by rapacious birds,” Davis notes.

Remnants of crab eaten by a bird, perhaps. This is evidence that not every Sally Lightfoot is too quick for predators to catch them. Photo by David Braun.

Sallys are prey for a number of other Galapagos species, including herons, turtles, and octopuses. They eat mostly algae, but also act as the beach sanitation squad, feeding on anything edible washed up or discarded by birds. The crabs have also been observed preying on turtle hatchlings and booby chicks, so they give as good as they take in the food chain. Read more about them on the Encyclopedia of Life website. Visit this site to see a photo of a Sally Lightfoot specimen collected by Charles Darwin on mainland South America.

Photo by David Braun

Brown pelican and green turtles. Photo by David Braun.

We picked our way past the Sallys to our Zodiac, observing a brown pelican preening itself on a rock. And there, just beyond the pelican, were the turtles still coupling. They had been at it the whole time we’d been on the volcano cone.

Zodiacs ferried explorers back to the ship or the beach alongside Pinnacle Rock for snorkeling, hovering over the submerged slopes of the volcano in the comfort of a glass-bottom boat, sunbathing alongside sea lions, or simply to sit on the rocks and contemplate the lizards.

Snorkeling Around Pinnacle Rock

Anthony and I elected to go directly to snorkeling on the beach. Anthony went out ahead of me and discovered some docile sharks lurking in underwater caves. He also saw a marine iguana feeding on an underwater rock, which he caught on video using a GoPro camera strapped on his head. The still image below is from his vide.

I floated lazily on the surface, content to gaze on the enormous schools of brightly colored fish around and below me. I was on the lookout for an octopus, which others had reported seeing in the general area, but I didn’t notice any in the kaleidoscope of marine organisms around me.

Picture of marine iguana feeding on a rock underwater, courtesy of Anthony Braun.

After another hearty meal on Endeavour, we boarded the Zodiacs in quest of Galapagos penguins and a visit to a famous small volcano called Sombrero Chino because of its resemblance to a Chinese hat. Touring tiny islets by Zodiac is a feature of the Lindblad-National Geographic expedition that I particularly enjoyed. Our crew would take us right up to rocks crammed with birds and crabs, and that was how we got to see at really close quarters one of the most intriguing birds of the islands, the Galapagos penguin.

Tropical Penguins

Photo of Galapagos penguin by David Braun.

Ordinarily, one would associate penguins with the ice floes and snowy ledges of the Antarctic. But here in the Galapagos they were testimony to yet another marvel of evolution: penguins on the equator.

The Galapagos penguin has a number of unique adaptations that allow it to survive the high temperatures and unpredictable food supply of the Galapagos, according to the Encyclopedia of Life. Foraging in the sea during the day helps them to avoid overheating, the EOL website says.  But the species also has a number of behavioral adaptations that allow these birds to keep cool on land, including standing with flippers extended to aid heat loss. (Read more about adaptations to heat and other facts about these remarkable birds on the Encyclopedia of Life’s Galapagos penguin website.)

The Galapagos penguin (Spheniscus mendiculus) once numbered in the thousands in the archipelago, but after a big setback in a particularly rough series of climate events over the last two decades, less than 2,000 may survive. The IUCN Red List and the United States Endangered Species Act list Galapagos penguins as Endangered. Bartolome, Sombrero Chino and the tiny islets around them are one of the few places where the world’s most northern colonies of penguins breed and survive.

“Due to climatic changes brought about by El Niño and La Niña cycles, the food supply available to the Galapagos penguins varies greatly,” explains the Encyclopedia of Life website. “These unpredictable shifts in food supply often lead to starvation and deaths and a substantial decline in the already dwindling penguin population. Furthermore, human disturbances and predation are major factors contributing to the decline of S. mendiculus. Human disturbance is the main cause for ecosystem harm that affects the nesting grounds of Galapagos penguins,” EOL says.

Photo by David Braun

Photo by David Braun

Our close-up inspection of a handful of penguins found them standing or lying motionless on the rocks. At least out here on these isolated islets they appear to be relatively safe from predators such as rats and domestic dogs. But they remain prey for hawks, sharks — and Sally Lightfoot crabs.

Photo by David Braun

Photo by David Braun