By Keith Coffman
DENVER (Reuters) - A 6-foot-long (1.83-meter), 25-pound (11-kg) Nile monitor lizard has escaped from his owner in a Colorado mountain community, prompting authorities to warn residents on Tuesday to keep children and small pets indoors until the carnivorous reptile is captured.
The black lizard, known as Dino, broke its nylon leash near Woodland Park, about 85 miles southwest of Denver on Monday and scampered away, said Teller County Sheriff Mike Ensminger.
"These lizards are pretty muscular and can be aggressive," Ensminger told Reuters.
As cold-blooded creatures, monitors need to sun themselves to maintain body heat, so animal-control officers are searching rock outcroppings during the daytime hours, Ensminger said.
Native to Africa, Nile monitors have long sharp claws, and powerful jaws that clamp down on prey, according to the Denver Zoo, which until recently housed a Nile monitor.
The Denver Zoo's female monitor died about a month ago where it had lived for 10 years, said zoo spokesman Sean Andersen-Vie. Animal-control officers in Cheyenne, Wyoming, had found the female lizard, which had either escaped or had been set free by its owner, he said.
In the wild, monitors feed on carrion, crocodile eggs, fish and birds, but in captivity they will eat small rodents and fish, the zoo said.
The Nile monitor's forked tongue, which is used to test the air for the scent of quarry, and its thick, keeled tail add to the reptile's dragon-like appearance.
Escaped Nile monitors have posed problems as an invasive species in Florida where they have bred and thrived in the tropical climate, said Denver veterinarian Kevin Fitzgerald, who specializes in reptile medicine.
The solitary monitor on the loose in Colorado may be able to find small mammals or birds to eat to survive for a while, Fitzgerald said, but also will have to elude predators such as foxes, coyotes, mountain lions and even large raptors.
Even if it finds prey, the monitor will freeze to death once temperatures plummet in the Colorado high country in late summer or early autumn, he said.
Fitzgerald said the broader debate should center on the "ethical and moral" issue of importing exotic animals for people to keep as pets.
"Why do we allow somebody to keep a subtropical, African species in a basement at 8,000 feet?" he said.
Ensminger said it is not illegal to own a monitor in Colorado, so unless Dino injures someone, it is unlikely authorities would lodge criminal charges against the owner.
(Reporting by Dan Whitcomb; Editing by Sandra Maler)