These dark colored, slender reptiles are endemic to the Aru Islands. They spend most of their lives in the treetops and are extremely agile, curious, and intelligent. Many species of monitor will use their tails as weapons to defend themselves, but black tree monitors are more careful with their tails because they can use them to grasp things like branches to help them climb.
Physical Description
Adults are covered in black, shiny scales. Males are generally larger than females. The lizard’s body is slender and the tail can account for up to two-thirds of an individual’s length. The species has long, sharp claws at the end of each of its toes, which, along with their prehensile tails, help them climb through the trees. Like snakes, monitor lizards also have long forked tongues that they flick in and out of their mouths to smell their surroundings.
Size
They are three to four feet long (0.9-1.2 meters), though most of that length is accounted for by their tail. Black tree monitors are large for lizards but smaller than other types of monitor lizard, including the massive Komodo dragon.
Native Habitat
Forests and mangrove swamps in eastern Indonesia, specifically the Aru Islands off the coast of New Guinea. This species spends much of its time in the forest canopy but will descend to the ground to find food.
Lifespan
Up to 15 years in the wild, but potentially longer in human care.
Food/Eating Habits
These carnivorous lizards feed mainly on small invertebrates, but they will also eat small mammals, amphibians, and baby birds or eggs.
Social Structure
Most monitors are solitary. Male black tree monitors can become aggressive toward other males that enter their territory. They will rear up on their hind legs and do battle for dominance. During the breeding season, males will allow females inside their territories.
Reproduction and Development
Female lizards will lay between 3 and 7 eggs, sometimes twice a year. Incubation lasts around 164 days and occurs in a nest that is usually up off the ground in hollows such as termite mounds, tree holes, or decaying logs. The mother will defend her offspring for a short period of time before the hatchlings become independent.
Conservation Efforts
The IUCN Red List of Threatened Species designates black tree monitors as ‘Data Deficient’, but indicates that their population is likely decreasing. The species’ limited range makes it more vulnerable to extinction and black tree monitors are commonly taken from the wild to supply the exotic pet trade. The species is listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, but is not protected in Indonesian New Guinea.
Habitat loss via deforestation and fragmentation are significant threats to these reptiles. More research is needed to understand the needs and conservation status of this species.
Help this Species
- Reduce, reuse and recycle — in that order! Cut back on single-use goods, and find creative ways to reuse products at the end of their life cycle. Choose recycling over trash when possible.
- Choose your pets wisely, and do your research before bringing an animal home. Exotic animals don’t always make great pets. Many require special care and live for a long time. Tropical reptiles and small mammals are often traded internationally and may be victims of the illegal pet trade. Never release animals that have been kept as pets into the wild.
- Support organizations like the Smithsonian’s National Zoo and Conservation Biology Institute that research better ways to protect and care for this animal and other endangered species. Consider donating your time, money or goods.
- Share the story of this animal with others. Simply raising awareness about this species can contribute to its overall protection.
Animal News
Get to Know the Herd of Asian Elephants Living at the Zoo
