The Los Angeles Zoo is proud to announce the hatching of three Gray’s (or Butaan) monitor lizards last month, achieving the rare honor of being the second facility in the Western Hemisphere in history to hatch a Gray’s monitor lizard. A single egg hatched at the Dallas Zoo in 1994, but the animal died shortly thereafter. There are currently only two AZA-accredited zoos in the U.S. that house Gray’s monitors, and the L.A. Zoo has the only breeding male.
Thought to be extinct in the wild for over 130 years, this shy, fruit-eating, arboreal species was rediscovered in 1975 and can only be found on a few islands in the Philippines. Known to be one of the largest lizards in Asia, the Gray’s monitor is olive-green in color and can grow up to six feet from snout to the end of its tail and weigh up to 20 pounds. Very little is known about the reproductive cycles of Gray’s monitors as 99 percent of their lives are spent in the canopy of trees, a fact which may play a part in why it’s so hard to hatch this species in captivity.
“We have had clutches of eggs in the past, but this has been the healthiest fertile clutch,” said Ian Recchio, curator of Reptiles and Amphibians at the Los Angeles Zoo. During the 270-plus day incubation period, L.A. Zoo reptile staff closely monitored the eggs but didn’t have any previous experience with hatching eggs of this particular species. They took their experience with similar Asian monitor species and their work hatching Komodo dragon eggs, and applied that knowledge to this clutch. “We were optimistic about the outcome as we watched the eggs develop, and when the first baby hatched to our surprise, it appeared strong and perfectly developed,” said Recchio.
The L.A. Zoo has had Gray’s monitors in its collection since 1998, but they were all received through illegal confiscations and none were babies. The adults are extremely hard to keep in captivity due to what they eat, an unusual diet consisting of indigenous fruit and invertebrates from the Philippines. L.A. Zoo reptile staff assumes the babies will follow suit, and they are already armed with plenty of tricks to help the newly hatched babies thrive like their parents.
“Staff currently maintains these hatchlings as individuals to manage their feedings and maintain their health,” said Recchio. “We treat them like smaller versions of the adult monitors. Sometimes we have to get pretty creative to get these monitors to feed, and we’ve been known to try tricks like injecting baby food into the dead mice they eat. Currently this clutch is responding best to food items such as snails, insects, and smaller pieces of fish.”
The three recently hatched babies are currently off-site at the zoo’s reptile holding facility
receiving exceptional care while being carefully observed by L.A. Zoo reptile staff.
“Before you can establish a captive breeding and conservation program, you have to understand how to keep the animal alive and ultimately how to reproduce it in captivity,” said Recchio. “We have taken huge strides forward in understanding the captive management of a rare and poorly understood Asian lizard.”
Once the hatchlings are well-established, the L.A. Zoo hopes to share its recent knowledge of this rare species and expand the breeding program here in the United States.
“The Los Angeles Zoo is extremely proud of our reptile staff and the hard work they have shown in pioneering a breeding program for this rare and vulnerable species of monitor,” said John Lewis, Zoo Director at the Los Angeles Zoo. “This is a great example of the important work zoos participate in that helps contribute to the conservation of a species. Our hope is that we can now share this knowledge and start to establish breeding pairs in other AZA-accredited zoos.”
This vision is on its way to becoming a reality as the three hatchlings continue to thrive and there is already a second clutch of eggs incubating at the zoo’s reptile holding facility that is due in July. Guests can now view the breeding pair of adult Gray’s monitors at the Living Amphibians, Invertebrates, and Reptiles (LAIR) building daily during zoo hours.