Of the original fourteen species, three are now extinct—the result of the hunting of adults for food and oil by buccaneers, whalers, and fur sealers (reducing the population by an estimated 200,000 tortoises); predation on the eggs and hatchlings by rats, pigs, and ants; and competition with goats and other large introduced mammals for food and habitat.
While there is physical variation between all the species, two main shapes exist—the domed carapace (the most ancient form) and the saddleback.
In 1959 with the establishment of the park and the Charles Darwin Foundation, a tortoise census was done and steps taken to preserve and increase the existing populations. At the time, most were on the brink of extinction and only their long lifespan has given the park authorities time to start increasing the species’ numbers through breeding.
There are now approximately 30,000 tortoises on the islands. The breeding center carefully tends the hatchlings until they are old enough to fend for themselves when they are released into the wild.
Note the detailed concentric circles on the baby tortoises shell plates. As the shells grow, the circle ridges get stretched out. The smoother the shell, the older the tortoise.
Over a hundred scientists, educators, volunteers, research students, and support staff from all over the world conduct scientific research and monitor the projects conducted at the Charles Darwin Research Station. This is done in conjunction and cooperation with its chief partner, the Galapagos National Park Service (GNPS), the principal government authority in charge of conservation and natural resource issues in the Galapagos.
Later in the afternoon, we had the opportunity to visit a lava tube. Ours extended for several kilometres, and was enclosed by high, jagged walls that disappeared into the gloom. We only ventured about 400 meters in. The tubes were formed when cooler outer parts of lava flows hardened into thick rock walls, providing insulation to keep a flow going inside; eventually the flow
Another action-packed day, a wonderful dinner on board our vessel, the Santa Cruz and later, a chance to enjoy the lights of Puerto Ayora.
Photos: R. Marion