Lonesome George about to become a father after 36 year wait

28/07/2008 08:43:47 After 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. However park rangers in charge of the "Fausto Llerena" Captive Breeding Centre have found a nest with eggs laid 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 Centre. 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, as the last of his species (Geochelone abigdoni), he showed no interest whatsoever in reproducing, despite being penned up with females from several different species.

Overweight
Twenty years ago, Linda Cayot, herpetologist of the Charles Darwin Foundation (CDF) from 1988 to 1998, found Lonesome George in a huge corral, alone, and overweight... Thus began a long and public process in search of a way for George to become a father. This dream is on the point of becoming reality - if in 120 days the three good eggs deposited by one of the females in George's corral are shown to be fertile.

Doctor Cayot, working for the CDF, supervised the Galapagos National Park's giant tortoise breeding and rearing program at the Tortoise Rearing Centre on Santa Cruz. One of the greatest challenges was to get Lonesome George to reproduce.

Tortoise diet
The first step, explains Dr. Cayot, was to ensure that George lost the excess weight gained during in his first 16 years of captivity. The diet began. "It is common in some reptiles that obesity can affect reproduction," assures Cayot.

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 or interest in breeding behaviour and was hostile toward his pen mates. Nevertheless, park rangers at the Breeding Centre began to notice a change of heart in the animal in the last few months. It has now been discovered that the tortoises of Española are genetically closest to the subspecies from Pinta, but in 1993 there were no genetic studies. A group of scientists from Yale University have also recently discovered a hybrid tortoise that shares half of its genetic material with Lonesome George (Geochelone nigra Abingdoni).

"With George installed in his new corral with two female companions, we began working on sexual stimulation, to try to induce George to reproduce. A Swiss volunteer, Sveva Grigioni, worked with him during a four-month period, but there were no advances," says Cayot.

Many experts, little success
Reproductive experts, animal nutritionists and veterinarians with expertise in tortoises were consulted. A diet rich in minerals and vitamins, prescribed by a nutritionist from the US National Zoo in Washington, DC, helped to improve George's overall health. Even Ian Wilmut, one of the ‘parents' of Dolly the sheep came to Galapagos to visit the most famous lonesome in the world... But nothing appeared to produce results.

All but given up
Once everything had been tried, many people had given up hope that George would ever reproduce, it appears that Lonesome George may have confounded everybody, though the results won't be known for several 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 Centre.

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.

9 eggs - only three intact
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.

Goats eradicated
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.