Wednesday

Giant tortoise with saddle or 'galapágos' shell, Charles Darwin Research Station

This day was spent totally on Santa Cruz Island. We took a small bus into the interior of the island to the giant tortoise reserve. This island 986 km² island has much agriculture and grazing but the Tortoises seemed coexist with cattle and organic coffee trees. We climbed to about 450 m elevation (the island rises to almost 900 m). The tortoises here are dome shell varieties that have evolved in lush vegetation so there has been no selective pressure favouring dome shell morphology. My cold was forgotten as we tramped along muddy trails in search of the tortoises. We were not disappointed. We saw many from dozing 'teenagers' to larger adults (the tortoises do not become sexually mature until they are about 25).

Dome back giant tortoise seeking refuge from biting insects in a muddy wallow. Tortoise refuge, highlands of Santa Cruz Island

Photo by Lionel Jackson

Smaller adult dome back giant tortoise, tortoise refuge, highlands of Santa Cruz Island. Photo by Lionel Jackson

I learned that the ring pattern on their shells disappears after they pass 100 years old! Our tortoise stalking was followed by a descent into another lava tube system nearby. I estimated its length at about 1000 m. At the other end we emerged next to a coffee bar where we enjoyed fresh fruit and java. Washington crawled into a tortoise shell to show how large some of these creatures are.

Seeing these giant tortoises in the wild was a thrill for me partly because several years ago I saw Aldabra giant tortoises in the other refuges of these gentle giants in the Seychelles Islands off the east coast of Africa in the Indian Ocean. In corresponding with Dr. William Joyce, a palaeontologist at the Peabody museum at Yale University after returning from this trip, I learned that the turtle body with its domed shell originated about 200 million years ago in the Triassic--about the time that the first dinosaurs made their debut. Turtles (including tortoises) are still around but the dinos are long gone. I guess slow and steady did win this race. Dr. Joyce informed me that the oldest fossil record of giant tortoises occur in the Paleocene which is dated between 65 and 55 million years ago. They are a relatively new innovation in turtledom.

After lunch and a siesta, we pushed on to the Charles Darwin Research Station where scientists from around the world are based when they do research on the islands. This institution is also dedicated to the preservation of species on the islands and has saved land iguanas and tortoises from extinction by rearing young in captivity and then releasing them back to the island of their origin. This is accompanied by extermination of feral species that are destroying the ecology of their island. We saw baby giant tortoises from various islands of all ages all carefully numbered so as not to repeat Darwin’s error of mixing specimens from different islands!

Entrance to Charles Darwin Research Station Photo by Lionel Jackson

1 year old tortoise hatchlings, Charles Darwin Research Station Photo by Lionel Jackson

We did some souvenir shopping in Puerto Ayora and chatted with our shipmates while we waited for the Zodiac to pick us up. Onboard, we met our new passengers, three Americans, two Belgians, and three Germans. One of the Americans was a surfer who had a camo headband. Washington christened him ‘Commando’. They were welcomed aboard with the usual coconut milk and sugarcane liquor cocktails.