Species Fact Profile: Black Tree Monitor (Varanus beccarii)

                                                   Black Tree Monitor

                                            Varanus beccarii (Doria 1874)

Range: Aru Islands (eastern Indonesia, off the coast of New Guinea)

Habitat:  Humid Forest, Lowland Rainforest, Mangrove Forest

Diet:  Insects, Small Lizards, Frogs, Crustaceans, Small Mammals, Birds, Eggs

Social Grouping: Solitary (not territorial)

Reproduction: Reproduction has not been observed in the wild, but it is theorized that they lay their eggs in arboreal termite nests or in tree cavities, which provide heat and humidity while still being dry.  Courtship consisting of the male chasing the female, with copulation taking place suspended off the ground.  Breeding may take place twice per years.  3-7 days incubated period 165 days.  Sexually mature at 2 years old

Lifespan: 10-15 Years

      Conservation Status:  IUCN Data Deficient, CITES Appendix II

• Sexes alike.  Hatchlings and juveniles are dark gray in color, with regular rows of bright yellow-green dots, particularly on the back.  As the animal matures, the skin turns completely black.  Scales are small and non-overlapping, forming a granular pattern
• Body length is approximately one meter, about two-thirds of which is made up of the long, thin tail.   The tail is prehensile and is used solely for climbing and balance, not at all for defense as is seen in many other monitor species.    The limbs are long and slender with elongated digits, large claws, and adhesive soles, all adaptations for life in the trees.  Males larger than females, with larger heads and broader tails.
• The teeth are large for a monitor, possibly an adaptation for holding onto prey animals seized in the treetops.  They will also use their long, slender limbs to fish prey animals out of crevices in the trees.
•  Captive specimens have been observed eating plant matter, but plants have never been detected in the gut content of wild monitors
• Natural predators are larger lizards and snakes.  They are also predated by foxes, which have been introduced to the islands.
• Have been observed engaging in bipedal ritual combat in the trees        
• Originally classified as a separate species, then reassigned as a subspecies of the emerald tree monitor (V. prasinus) before being re-elevated to full-species status in 1991, though still part of the V. prasinus species complex, along with the emerald, blue, and yellow tree monitors
• Species name honors the Italian explorer Odoardo Beccari (1843-1920), who explored and collected in New Guinea, Indonesia, and Malaysia
• Very poorly studied in the wild, with much of the available information coming from captive specimens.  It is assumed that the species is primarily arboreal and spends most of its time in the canopy, but studies with other tree monitors suggest that it may be more terrestrial
• Loss of habitat due to deforestation and collection for the pet trade are believed to be the primary drivers of the decline.