Lonesome George could leave behind offspring. | July 24th, 2008

Lonesome George could leave behind offspring
It will be 120 to 130 days before it is known if eggs are fertileAfter 36 years of continual and exhaustive efforts, when it seemed impossible that the tortoise called “Lonesome George” – the last survivor of the Pinta Island giant tortoise species (Geochelone abigdoni) – would be able to reproduce, this morning park rangers in charge of the “Fausto Llerena” Captive Breeding Center found a nest with eggs laid last night by one of the two Wolf Volcano females that have shared a pen with him since 1993.

In 1972, George was found during a hunt for wild goats on Pinta Island and taken to the Galapagos National Park’s Giant Tortoise Captive Breeding Center. Back then, there was hope he would reproduce and that the island could be repopulated with this giant tortoise species. That task, however, turned out to be fruitless, since the last of the Geochelone abigdoni showed no interest whatsoever in reproducing, despite being penned up with females from several different species.

Subsequently, after various studies conducted by the Charles Darwin Foundation, two Geochelone becki females from Wolf Volcano, phenotypically similar in shell form, were placed in his pen in 1993. During all these years of cohabitation, Lonesome George showed no evidence of breeding behavior and was hostile toward his pen mates. Nevertheless, park rangers at the Breeding Center began to notice a change of heart in the animal in the last few months.

“Previously, George would attack his companions and was very territorial. We even had to feed him separately from the females, but now he accepts them and shares meals with them,” states Fausto Llerena, the park ranger who has cared for George since he was moved to the Center.

Things progressed to the point that two weeks ago park rangers observed a female known as No. 107 scraping the earth in nesting ground areas provided within the pen. Finally, this morning when park rangers made their rounds, they found a nest built last night.

Once the news was reported, park rangers opened the nest and removed the eggs to be incubated in the laboratory. Out of nine eggs laid, four were completely broken, two had cracked shells, and only three were intact. These were placed in incubators, two at a temperature of 29.5 °C (85.1 °F) to obtain females and one at 28 °C (82.4 °F) to obtain a male. There will be a wait of 120 to 130 days before it is known if the eggs are fertile and George will have offspring. Even if these three eggs are fertile, and the baby tortoises manage to survive, several generations will have to go by (genetically speaking) before it can be said that pure individuals of the Pinta species have been obtained. This will take centuries, considering the longevity of the tortoises and their late sexual maturation.

In 2003, the Galapagos National Park succeeded in eradicating feral goats from Pinta Island. Since the only native herbivores – the tortoises – were missing, undesirable changes began to take place in the island’s vegetation. In view of George’s apparent inability to reproduce, the GNP and the Charles Darwin Foundation, with advice from a number of scientists around the world, developed the Pinta Island Ecological Restoration Plan, which involves introducing the Española Island tortoise species to fulfill the role of Pinta ecosystem engineers.

In view of the many other species, ecological and evolutionary processes that must go on, the Galapagos National Park will proceed with the implementation of this ambitious plan as part of its “Ecosystemic Approach” to Galapagos conservation.