Log Entry from Trina Litchendorf

The students and professors had arrived in Quito, Ecuador over the past few days and had spent the time sightseeing around the city.  This morning we left Quito for Baltra Island, a small island north of Santa Cru z , and arrived shortly before noon.  After deplaning we boarded a bus for the drive to the southern end of the island where we loaded our luggage onto a small ferry for the short trip across the channel to Santa Cruz Island .  Once on the other side we boarded a bus for the 45-minute drive to Puerto Ayora.  Onboard Ignacio, a naturalist, explained how the vegetation on the island differs on the northern and southern side of the island.  The SE trade winds bring moisture to the islands and as a result the southern side is much more lush and green while the northern side is dry and arid. 

After getting settled at Hotel Mianao we headed over to the Charles Darwin Research Station, there Roslyn Cameron, the development manager of the center, gave us a tour of the captive breeding program for the giant Galapagos tortoises.  We learned that the greatest threats to the giant tortoises are invasive

species that have been introduced, intentionally or not, by man.  Cattle, goats and pigs eat and destroy the cactuses and vegetation that provide food and cover for the tortoises and cats, rats and ants are a threat to the eggs and young tortoises.  The problem is so bad that a study done on South Isabella island found that only 6% of the tortoise eggs hatched and afterwards, there was essentially a 0% survival rate of the young, because of predation by rats and cats. 

We were also introduced to Fausto Llerena, one of the original park wardens who has worked for the program for 30 years and for whom the Captive Breeding Center is named after.  He supervises daily operations of the breeding program and he has a deep love of the tortoises.  It turns out that the giant tortoises are perfect for captive breeding, as they have no mothering instinct.  The Natural Park wardens and herpetologists collect the eggs in the wild after the female lays them.  Unlike turtle eggs, which are leathery, the giant tortoise’s eggs are fragile like a chicken egg, so the female secretes a gel-like substance to protect them.  The eggs are brought back to the breeding center where they are placed in a wooden incubator closet and incubated for 120 days.  The temperature of incubation has been shown to influence the sex of the hatchlings so the center tries to skew the birthrate towards females. As a result of the attentive care, the Center has an 85% hatching rate.  When the baby tortoises come out of their eggs, they are no bigger than a tennis ball.  We were given a special treat by Fausto and allowed to peek at the 30- day old hatchlings. 

Photo 2:  Fausto shows us the incubator.  Tortoise eggs are in the plastic 

Photo 3: The 30 day-old babies

Photo 4:  The young tortoises, here they are about 9 inches long and under 2 years old.

 When the babies are just a little bigger they are moved to covered, outdoor pens and are very well cared for the first two years of their lives.  After their 2^nd birthday, they are placed in outdoor adaptation pens where they learn how to scavenge for food and right themselves if they turn over, basically learning how to be tortoises.  The only natural predator of the tortoises is the Galapagos hawk, but it is only a threat to the young tortoises so the Center raises them until they are 5 years old before releasing them back to the wild.  This conservation work is not cheap.  From the time the eggs are collected until the 5-year old tortoises are released, the cost averages $5000 per tortoise. 

Originally there were 14 species of giant tortoise on the Galapagos Islands and they numbered in the millions but in the 18^th and 19^th century they were decimated by whalers who harvested them for food.  These tortoises can live for a year without food or water, so they would stack them by the hundreds in the holds of their ships as a source of fresh meat while out at sea for long periods and invasive species on the islands further threatened them.  Today there are only 10 viable species and one single member of a species from Pinta Island , “Lonesome George” is the last of his kind.  But the work of the Center has been very successful.  The saddleback tortoises of Española were down to just 13 living animals, 2 males and 11 females.  But captive breeding efforts were not going well until “Diego”, an Española tortoise at the San Diego Zoo, was sent home to the Galapagos to save his species.  Diego jump started the breeding efforts, so to speak, and today Española Island represents a shining example of the Center’s conservation efforts.  One hundred percent of the invasive species have been eradicated from the island and there are now1500 Española tortoises repatriated to the island. By 2007 the Center aims to have all feral pigs and goats eradicated from the park areas.  Roslyn said that if the combination of science and management can remove the invasive species the tortoises are going to survive.

After our visit to the Darwin Center , the students split up to explore the area and get dinner.  Tomorrow is a free day for the students, and we will be going on several different day trips of our own choosing.

To learn more about the efforts to restore the Galapagos tortoises visit the Charles Darwin Foundation at:
http://www.darwinfoundation.org/