Nile monitor lizards inhabit woodlands, dry savanna, scrub, evergreen thickets and swamps in central and southern Africa. They are usually found near rivers, lakes and pans. They can live up to 5,000 feet above sea level. Nile monitors are carnivores.
There are 31 species of monitor lizards in the world. Nile monitors have been introduced to waterways in south Florida, either as an intentional release or as exotic pets escaping captivity.
Monitor lizard behavior and facts
- Monitor lizards prey on crocodile eggs, fish, frogs, turtles, rodents, lizards, mussels, crabs and snails. They use both their eyesight and long, forked tongues to sense prey.
- They are semi-aquatic (active on land and in water). They are excellent swimmers and divers and can remain underwater up to one hour. They can also climb trees, to lie in branches overhanging rivers, or to escape danger.
- Their main predators are crocodiles and pythons.
- They are solitary, and dig burrows for shelter. They may drop from a high branch into water to avoid contact with predators or humans.
From birth to death
- Nile monitors breed once each year, following the rainy season.
- The female digs a hole in the ground or in an active termite nest. Over 2 to 3 days, she lays 20 to 60 eggs.
- Incubation: up to 1 year
- Hatchlings weigh less than 1 ounce. After hatching, they may need to wait for rain to soften the hard nest, or the female may return to open the nest to free them.
- Once they leave the nest, hatchlings receive no maternal care.
- Sexual maturity: 3 to 4 years
- Lifespan: 10 to 20 years in captivity
- Length: 5.5. to 7 feet
In 1975, some North African states replaced the Wild Animals Law created in 1963 with a new law that gives protection to crocodiles, pythons, and monitor lizards. Nile monitors are also listed under the Endangered Species Decree of 1985, which means that international trade of the species in prohibited. This species is listed under CITES, Appendix II.
Monitor lizards, the Oregon Zoo and you
The zoo's Nile monitor, named Merlin, lives in the Africa Rainforest. Its daily diet consists of small whole prey items several days a week including: chicks, rats, mice and quail.