The San Diego Zoo acquired its first two Komodo dragons in 1968. They were believed to be a "pair" (male and female), but were too young when they arrived for us to be absolutely certain about that. It wasn’t until 1975 when the animals were sexually mature that hormonal analyses revealed that they were both females, and so we began to search for a breeding-loan male. Named One Eye, that male arrived from the Basel Zoo in Switzerland in 1976, but no offspring were ever produced.
Currently, we have two dragons at the San Diego Zoo. A juvenile can be seen in our Reptile House. A very handsome adult male, named Sunny, lives in a specially designed enclosure with indoor and outdoor access, heated waterbed platform, and gas heaters for warmth, as well as opportunities for his keepers to provide enrichment for him. Sunny is a curious, intelligent, and mild-mannered dragon who comes when his keepers call him. Hatched at the Honolulu Zoo in 2000, Sunny arrived at our zoo in 2006. He is now 8.6 feet (2.6 meters) long and weighs 123 pounds (56 kilograms).
The Komodo dragons at the San Diego Zoo are fed a diet of rabbits, rats, mice, a commercial reptile diet, and beef shank. Occasionally, hard-boiled eggs and fish are offered as treats. As reptiles, dragons rely on external heat sources like the sun to maintain their body temperature, so they don’t need as much food as a comparatively sized mammal. Care must be taken by our keeper staff when in the Komodo dragon exhibit, as the lizards attempt to eat any materials the keeper may leave behind. Everything is edible until proven otherwise!
As part of the Association of Zoos and Aquarium’s Species Survival Plan for Komodo dragons, the animals are often moved from zoo to zoo, based on breeding needs. There are two juvenile dragons who take turns being on exhibit in the corner of our Reptile House, as they are not compatible. Nacho, a male, and Mezcal, a female, hatched from the same clutch at the Los Angeles Zoo in August 2010 and moved here in April 2011. They are about 2 feet (0.6 meters) long and have the bright colors typical of young Komodo dragons.
Whether looking at dragons small or large, we hope you appreciate these living legends!
The magnificent Komodo dragon is vulnerable. Some might think that the largest lizard in the world wouldn’t have to worry about its safety. One study estimated the population of Komodo dragons within Komodo National Park to be 2,405. Another study estimated between 3,000 and 3,100 individuals. On the much larger island of Flores, which is outside the National Park, the number of dragons has been estimated from 300 to 500 animals. Komodo dragons that live outside of the National Park are at greatest risk, as habitat fragmentation and frequent burning of grasslands to hunt Timor deer are the greatest risks to their survival. On the island of Flores, Komodo habitat is shrinking quickly because of the impact of a human population of approximately 2 million.
In 1994, the San Diego Zoo received six young Komodo dragons on loan from the Cincinnati Zoo. We planned to find an easy, safe way to determine the gender of Komodos at a young age. After nine months of blood sampling and ultrasound exams, we found that we could determine the gender of two-year-old dragons successfully. This knowledge is tremendously helpful for managed-care breeding programs. The technique also proved successful in determining the gender of all our monitor lizards as well as Gila monsters and beaded lizards.
San Diego Zoo Global has a research and conservation program to help these carnivorous giants. We are conducting research to understand the population biology of Komodo dragons in Komodo National Park. By studying Komodo dragon births, deaths, survival, and growth, we hope to learn many important things that will enable us to better conserve and manage these animals within the wild. In addition, we conduct many other types of research to understand how things such as prey availability and rainfall influence the biology of the different dragon populations across Komodo National Park.
Before we started this project, many basic pieces of information that are needed to manage and conserve Komodo dragons were unknown, including how many Komodo dragons live on each island, how different he populations are among the islands, and if the dragons move much among islands. Over the years we have been able to provide answers to some of these questions. For example, we now know that despite living across several islands, dragons only occasionally swim to other islands and thus seem to be homebodies.
Furthermore, Komodo dragons tend to remain within the same valleys they were hatched in. Only rarely have any individuals been recaptured in a different location from where they were initially discovered. Similarly, females often nest in the same nest location each time. We have some initial information that suggests that to become a very big male it may take as much as 20 years of growth, while for females 5 to 7 years seems to be when they are reach maturity.
We still have much to learn about these incredible reptiles!