Black tree monitor
Encyclopedia
The black tree monitor (Varanus beccarii), or Beccari's monitor is a relatively small member of the Varanidae
family, growing up to about 90–120 cm (35.4–47.2 in) in length. They inhabit the Aru Islands
off New Guinea
, living in an arboreal habitat. Their skin color is completely black, lending the monitor its name.
, 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. It has been argued that 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.
The generic
name Varanus is derived from the Arabic word waral (ورل), which translates as "monitor" in English. Its specific
name, beccarii, is named after the Italian explorer Odoardo Beccari
.
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.
s such as shrew
s. They may also take scorpion
s, eggs, and nestlings. They are themselves preyed upon by larger lizard
s and snakes, as well as fox
es, which were introduced to the region. They are also hunted by humans.
in Indonesia
, where it is known locally as waweyaro. It mainly inhabits humid forests and mangrove swamps.
, 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.
Varanidae
Varanidae is a group of lizards of the superfamily Varanoidea. The family is a group of carnivorous lizards which includes the largest living lizard, the Komodo dragon, and the crocodile monitor. Varanidae contains the living genus Varanus and a number of extinct taxa...
family, growing up to about 90–120 cm (35.4–47.2 in) in length. They inhabit the Aru Islands
Aru Islands
The Aru Islands are a group of about ninety-five low-lying islands in the Maluku province of eastern Indonesia. They also form a regency of Indonesia.-Geography:...
off New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, living in an arboreal habitat. Their skin color is completely black, lending the monitor its name.
Taxonomy
Varanus beccari was first described as Monitor beccari by DoriaGiacomo Doria
Marquis Giacomo Doria was an Italian naturalist and politician.He was the founder of the Museo Civico di Storia Naturale in Genoa in 1867, and director from then until his death...
, in 1874. Years later, it was classified as a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the emerald tree monitor
Emerald tree monitor
The Emerald Tree monitor , or the Green Tree monitor, is a small-to-medium-sized arboreal monitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, transverse dorsal banding. This coloration helps camouflage it in its arboreal habitat...
(V. prasinus), but a 1991 review of the complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...
returned V. beccari to species status. It has been argued that it should be maintained as a subspecies of the emerald tree monitor based on similarities in their hemipeneal
Hemipenis
A hemipenis is one of a pair of intromittent organs of male squamates .Hemipenes are usually held inverted, within the body, and are everted for reproduction via erectile tissue, much like that in the human penis. Only one is used at a time, and some evidence indicates males alternate use between...
structures, but genetic
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
evidence supports their treatment as different species.
The generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name Varanus is derived from the Arabic word waral (ورل), which translates as "monitor" in English. Its specific
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
name, beccarii, is named after the Italian explorer Odoardo Beccari
Odoardo Beccari
Odoardo Beccari was an Italian naturalist perhaps best known for discovering the titan arum, the plant with the largest unbranched inflorescence in the world, in Sumatra in 1878...
.
Description
Hatchlings and juveniles are a dark grey in colour, with regular rows of bright yellow-green dots which are particularly noticeable on the back. As they achieve adulthood, they turn completely black, losing the colourful dots. Fully grown specimens reach 90–120 cm (35.4–47.2 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 mammalMammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s such as shrew
Shrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
s. They may also take scorpion
Scorpion
Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...
s, eggs, and nestlings. They are themselves preyed upon by larger lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s and snakes, as well as fox
Fox
Fox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es, which were introduced to the region. They are also hunted by humans.
Distribution
The species is native to the Aru IslandsAru Islands
The Aru Islands are a group of about ninety-five low-lying islands in the Maluku province of eastern Indonesia. They also form a regency of Indonesia.-Geography:...
in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, where it is known locally as waweyaro. It mainly inhabits humid forests and mangrove swamps.
Conservation
Varanus beccarii is not on the IUCN red listIUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
, 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.