The long-term goal of Galapagos Conservancy’s Giant Tortoise Restoration Initiative, carried out in collaboration with the Galapagos National Park Directorate, is to rebuild Galapagos tortoise populations to their historical numbers. This includes returning tortoises to islands where humans caused their extinction. An analog species (Española tortoises — genetically closest to the original Santa Fe tortoises) will soon be released on Santa Fe to initiate the return of giant tortoises to an island where they went extinct in the mid 1800s.
By guest author Dr. James Gibbs of the State University of New York’s College of Environmental Science and Forestry (SUNY-ESF). All photos © James Gibbs.
This morning under the intense equatorial sun, we are searching for tortoises, specific tortoises, in the Fausto Llerena Tortoise Center on Santa Cruz. Scouring the grounds, we look for 5-to-10-year-old tortoises with celeste blue numbers on their shells. Freddy Villalva — Park ranger and head tortoise keeper — has given us a list of over 200 Española tortoises to find. The colored number indicates the island, and the color for Española is celeste blue. Freddy’s list includes all Española tortoises large enough to be released on Santa Fe.
This feels like an Easter egg hunt combined with a massive accounting exercise. Each tortoise has secreted itself somewhere on these rocky grounds amongst some 1,000 tortoises from different islands, each island with its own color of paint. Finding the right Española tortoises amongst the horde is a challenge. Normally this would be more difficult given tortoises’ propensity to hide themselves in the deep shade under thorn bushes, but fortunately this hunt was organized around a scheduled feeding day. Hungry tortoises come out from their hard-to-reach refuges looking for something to eat, making them easier to intercept.
As for an accounting exercise, we need to find and collect the correct tortoises, and only the correct tortoises. And 200+ tortoises is a lot of tortoises! For several years, Galapagos National Park staff have been rearing these tortoises specifically for Santa Fe Island. Each tortoise is the fruit of much labor, water, food, and care. Through population modeling, we have projected the future population on Santa Fe based on numbers released initially and through the years. It’s all been in the abstract, but suddenly here they are! It’s happening now. The first step is to find each and every tortoise on the list.
Any likely tortoise found is carried back to a large central pen with a divider. All tortoises are first put on one side, and when their number is checked against the master list, any tortoise that’s a “keeper” is put on the other side. If not on the list, it gets lugged back to where it was found. As we work through the lot, there are still a few “wanted” tortoises unaccounted for. This triggers a new, more thorough search for the missing tortoises. After a few more hours, we have 207 Española tortoises ready to go. It’s hot, sweaty, itchy work, but very exciting.
Next we measure and weigh each tortoise. This provides essential baseline data for determining their future fitness after being released on Santa Fe. Once “processed,” they are given fresh, seedless plant food just brought from the highlands and their water bath is replenished. They dine and sequester themselves together in the shade of their more confined corral to digest. Keeping them in a confined space on a “clean diet” (no seeds) for the next few weeks will clean out their digestive systems and avoid carrying any unwanted seeds to Santa Fe Island.
This was one long day. Tomorrow we will resume with the tortoise measurements and plan the next phase – affixing many with radiotelemetry devices to be able to track them upon release, and injecting all with tiny individual identification chips. We will keep you updated on their progress. The target release date is June 5, 2015. After weeks of heavy rain, there should be lots to eat on Santa Fe, but a one-day exploratory trip will be made before the tortoises’ release to ensure that this is the case.
For now, the future Santa Fe tortoise population is cloistered together in the Tortoise Center. Along with an occasional finch song and the happy chatter of the Park and GC crew finishing up for the day, I hear the pervasive swishing of hundreds of tortoise feet moving across the fine gravel of the pens as the tortoises head for the shade. We will resume tomorrow…
Dr. James Gibbs is Professor of Vertebrate Conservation Biology and Associate Chair of the Department of Environmental and Forest Biology at the State University of New York (SUNY-ESF). He has partnered with Galapagos Conservancy for many years in efforts to restore giant tortoise populations in Galapagos through the Giant Tortoise Restoration Initiative, and is a frequent guest contributor to the GC blog.