Black tree monitor
|Black tree monitor|
|Taken at the Cincinnati Zoo|
The black tree monitor or Beccari's monitor (Varanus beccarii) is a relatively small member of the Varanidae family, growing to about 90–120 cm (35–47 in) in length. They inhabit the Aru Islands off New Guinea, living in an arboreal habitat. Their skin color is completely black, lending them their name.
V. beccari was first described as Monitor beccari by Doria, in 1874. Years later, it was classified as a subspecies of the emerald tree monitor (V. prasinus), but a 1991 review of the complex returned V. beccari to species status. Arguably, it should be maintained as a subspecies of the emerald tree monitor based on similarities in their hemipeneal structures, but genetic evidence supports their treatment as different species.
Hatchlings and juveniles are a dark grey in colour, with regular rows of bright yellow-green dots which are particularly noticeable on their backs. As they mature, they turn completely black, losing the colourful dots. Fully grown specimens reach 90–120 cm (35–47 in) in length, with the males slightly larger than the females.
The black tree monitor is generally well adapted for living in trees. Its tail is particularly long, sometimes two-thirds of the overall body length, and is used in a prehensile manner to stabilize the animal in the branches. In fact, the tail is used solely for this purpose, as the animal does not evince the defensive tail-lashing behaviour seen in other monitor species. The black tree monitor’s feet sport large claws and adhesive soles, which help it to maintain grip in the trees. It also has unusually long teeth for a monitor of its size, which may help it to hold on to prey it catches in the canopy. Black tree monitors in the wild are reported to be nervous and high-strung; they will flee if threatened, and if handled carelessly, will scratch, bite, and defecate on the offender.
Predators and prey
Black tree monitors are carnivorous, consuming insects, smaller lizards, and small mammals such as shrews. They may also take scorpions, eggs, and nestlings. They are preyed upon by larger lizards and snakes, as well as foxes, which were introduced to the region. They are also hunted by humans.
V. beccarii is not on the IUCN red list, but it is vulnerable to loss of habitat due to its restricted range. It is also popular in the pet trade, with most specimens being captured from the wild because they need so much room to breed in captivity.
- "Varanus beccarii". Integrated Taxonomic Information System. Retrieved 28 August 2008.
- Doria, Giacomo (1874). "Enumerazione dei rettili raccolti dal Dott. O. Beccari in Amboina alle Isole Aru ed alle Isole Kei durante gli anni". Ann. Mus. Civ. Stor. Nat. 6.
- Netherton, John; Badger, David P. (2002). Lizards: A Natural History of Some Uncommon Creatures, Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN: Voyageur Press. p. 137. ISBN 0-7603-2579-0.
- Sprackland, R.G. (1991). "Taxonomic review of the Varanus prasinus group with descriptions of two new species". Mem. Queensland Museum. 3 (3): 561–576.
- Böhme,W. and T. Ziegler (1997). Varanus melinus sp. n., ein neuer Waran aus der V. indicus-Gruppe von den Molukken, Indonesien. Herpetofauna 19 (111): 26-34
- Ziegler, T., A. Schmitz, A. Koch and W. Böhme (2007). A review of the subgenus Euprepiosaurus of Varanus (Squamata: Varanidae): morphological and molecular phylogeny, distribution and zoogeography, with an identification key for the members of the V. indicus and the V. prasinus species groups. Zootaxa 1472: 1-28
- King, Ruth Allen; Pianka, Eric R.; King, Dennis (2004). Varanoid Lizards of the World. Bloomington: Indiana University Press. pp. 225–229. ISBN 0-253-34366-6.
- Cogger, Harold; Zweifel, Richard (1992). Reptiles & Amphibians. Sydney: Weldon Owen. ISBN 0-8317-2786-1.
- Monk, Kathryn A.; De Fretes, Yance (1997). The Ecology of Nusa Tenggara and Maluku. Periplus Editions. ISBN 962-593-076-0.