Diego is a Giant Galapagos tortoise who has played an active role to help save his species. Being well over 100 years old, Diego has fathered about 800 offspring since the 1960s. Reviving the Galapagos tortoise population has been an ongoing mission for scientists and conservationists, and efforts in captive breeding have helped the Galapagos tortoise slowly revive.
How Giant Galapagos Tortoises Became Endangered
The Galapagos Islands have been known for the giant tortoises endemic to the region. On each island the tortoises vary in size and shape of their shells, ranging from small saddle-backs to large dome-shaped tortoises. Unfortunately, over 100,000 giant tortoises were killed by whalers and colonists in the 19th and 20th centuries. They were killed for oil and as a fresh source of meat by visiting ships on long voyages. Humans also brought domestic animals to the Galapagos Islands such as dogs, pigs, donkeys and black rats, which had detrimental effects to the giant tortoise population. Pigs scavenge through tortoise nests to eat their eggs, rats eat hatchlings, goats compete for food, donkeys trample on the nests, and dogs can kill tortoises up to 4 years of age.
Before humans and their domestic animals came into the picture, there were several hundred thousand tortoises on the Galapagos Islands. Now, less than 15,000 survive. The Espanola subspecies was reduced to 12 females and 2 males, which further inhibited breeding opportunities. Thankfully in 1959 the Galapagos was declared a national park, making the islands’ native wildlife legally protected. Since then the Galapagos National Park Service and the Charles Darwin Research Station established the captive breeding center on Santa Cruz Island to help revive the endangered tortoise population.
Diego's Success to Save the Species
One of the most impressive success stories to save the species is with Diego the Galapagos tortoise. Diego was found at the San Diego Zoo in the 1950s and brought back to the Galapagos in 1976 for their captive breeding program. Recent genetic studies have found that Diego has single-handedly fathered about 800 offspring. This is quite an impressive number because it makes up about 40% of the 2000 Galapagos tortoises that have been bred in captivity and released back in the wild.
Currently there are three males chosen to help repopulate Santa Cruz Island with Galapagos tortoises. Out of the three males assigned, scientists consider Diego the dominant tortoise. Tortoise preservation specialist, Washington Tapia, says that Diego is a very sexually active male who has greatly contributed to repopulate the Galapagos Islands. Diego still lives on Santa Cruz Island as a hefty tortoise of 175 pounds, 35 inches in length and 5 feet tall. He currently shares an enclosure with six females at the tortoise breeding center. Despite being over 100 years old, Diego still contributes to the survival of his species.
Ongoing Conservation Efforts
Captive rearing has helped to increase the giant tortoise populations all over the Galapagos Islands. Even the Espanola subspecies has slowly been recovering. The Espanola tortoises were brought to the breeding center between 1963 and 1974 to encourage breeding and further monitoring. After eggs were laid they were placed in incubators until hatching to ensure that they wouldn’t be harmed in the wild. Young tortoises were reared in the center for about 3 years, and once they were large enough the tortoises were returned to the wild. By 1995 about 700 Espanola tortoises were brought back to the island.
Other programs have been established to collect eggs from nests to be brought back to the breeding center for incubation. The tortoises are reared at the center and eventually released back into the wild. Many tortoises have been saved by the threat of humans and introduced animal, and because of these efforts about 2000 tortoises have been released to their island of origin. For continual success of the program, a second rearing center was opened in the early 1990s.
To ensure that the giant Galapagos tortoises live on, it’s important that conservation efforts are continued. Fortunately there are many institutions that support the research and rearing of the giant tortoises. Some of these institutions include: The Ecuadorian Government, Friends of Galapagos, World Wide Fund for Nature (WWF), United Nations Development Program, and the Frankfurt Zoological Society Help for Threatened Wildlife. As humans it’s also important to assess our impacts on wildlife. We must be aware and conscious of how we can impact the ecosystem around us.