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Varanus dumerilii

Dumeril's monitor (Varanus dumerilii), also known as the brown rough-necked monitor, is a species of lizard endemic to Southeast Asia. Primarily found in dense evergreen forests and mangrove swamps, these monitors are characterized by their dark brown coloration and distinct yellow crossbars on the back, with juveniles displaying a striking orange-red or yellow head. They are known crab specialists but have a varied diet and are diurnal and arboreal in their behavior.

Key Facts

  • Endemic to Southeast Asia, including parts of Burma, Thailand, Malaysia, Singapore, Borneo, and Sumatra.
  • Adults can reach up to 1.4 meters (4.5 ft) in total length.
  • Distinctive coloration includes dark brown bodies with yellow crossbars and a shiny orange-red or yellow head in juveniles.
  • Primarily a crab specialist but also consumes snails, insects, fish, eggs, birds, and small rodents.
  • Arboreal and diurnal, meaning they live in trees and are active during the day.
  • Oviparous, laying clutches of 4-23 eggs, with up to three clutches per year.
Varanus dumerilii
Scientific Name
Varanus dumerilii
Family
Varanidae
Common Names

Dumeril's Monitor, Brown Rough-Necked Monitor, TúDtū̀

Geographic Distribution

Burma, Thailand, Peninsular Malaysia, Singapore, Borneo, Sumatra, Riau, Bangka–Belitung, Other Smaller Islands of Indonesia

Physical Description
  • Adults Can Reach Up To 1.4 m In Total Length; Typical Total Length Is 1.2 m .
  • Largely Dark Brown Coloration With Occasional Brighter, Indistinct Crossbars On the Back.
  • Juveniles Have A Shiny Orange-Red Or Sometimes Yellow Head, Which Fades After 4–8 Weeks.
  • Possess A Long, Laterally Compressed Tail With A Keel.
  • May Be Confused With the Black Rough-Necked Monitor Due To Large Nuchal Scales.
Diet

Crabs, Snails, Molluscs, Insects, Fish, Frogs, Turtle Eggs, Birds, Smaller Rodents

Lifespan Years
Not specified in the text
Behavioral Traits
  • Arboreal
  • Diurnal
  • Observed To Engage In Ritualized Combat In Captivity.
Diet Category
Threats

Pet Trade, Exportation From Indonesia

About Varanus dumerilii

Dumeril's Monitor (Varanus dumerilii)

Dumeril's monitor, scientifically known as Varanus dumerilii, is a species of monitor lizard native to the diverse ecosystems of Southeast Asia. It is also commonly referred to as the brown rough-necked monitor. This species is found across a range that includes southern Burma, parts of Thailand, Peninsular Malaysia, Singapore, and the islands of Borneo, Sumatra, and others within Indonesia. Historically, two subspecies were described, but current scientific consensus recognizes Varanus dumerilii as a monotypic species with no distinct subspecies.

Habitat and Description

The preferred haunts of Dumeril's monitor are dense, humid evergreen forests and mangrove swamps, environments they inhabit from sea level up to elevations of 900 meters. Adult specimens typically reach a total length of about 1.2 meters (4 feet), with some individuals growing up to 1.4 meters (4.5 feet). Their physical appearance is characterized by a predominantly dark brown body, often adorned with indistinct, brighter crossbars on the back. A striking feature is the head coloration of juveniles, which is a shiny orange-red or yellow, a hue that typically fades within the first few weeks of life. The tail is notably long and laterally compressed, featuring a distinct keel. They can sometimes be mistaken for the black rough-necked monitor due to shared traits like large nuchal scales.

Diet and Behavior

Dumeril's monitors are primarily specialists in consuming crabs, demonstrating a significant dietary reliance on these crustaceans. However, their opportunistic feeding habits extend to a varied diet that includes snails, other molluscs, insects, fish, frogs, turtle eggs, birds, and smaller rodents. Behaviorally, Varanus dumerilii is classified as both arboreal, meaning it lives in trees, and diurnal, indicating it is active during daylight hours. Less is known about this species compared to other monitor lizards, but observations include successful captive breeding and instances of ritualized combat in captivity.

Reproduction and Conservation

Reproduction in Dumeril's monitor is oviparous, with females laying clutches typically ranging from 4 to 23 eggs. It is possible for a female to produce up to three clutches within a single year. Hatchlings emerge with a snout-to-vent length of approximately 8 cm. The species has been bred successfully in both zoo environments and private collections. Despite this, Dumeril's monitor faces pressures from the pet trade, leading to significant export numbers from Indonesia, which does not list it as a nationally protected species. Consequently, the European Union has restricted the import of wild-caught specimens since 1997, reflecting concerns over its exploitation.

Source: Wikipedia ↗

Frequently Asked Questions

What is the scientific name for Dumeril's monitor?

The scientific name for Dumeril's monitor is Varanus dumerilii. It belongs to the family Varanidae.

Where can Dumeril's monitor be found?

Dumeril's monitors are distributed across Southeast Asia, including southern Burma, parts of Thailand, Peninsular Malaysia, Singapore, Borneo, Sumatra, and other Indonesian islands.

What is the typical habitat of Varanus dumerilii?

Their preferred natural habitat includes dense evergreen forests with high humidity and mangrove swamps. They can be found at altitudes ranging from sea level up to 900 meters.

What do Dumeril's monitors eat?

These lizards are primarily crab specialists. Their diet also includes a variety of other food items such as snails, molluscs, insects, fish, frogs, turtle eggs, birds, and small rodents.

How large do Dumeril's monitors get?

Adult Dumeril's monitors can reach a total length of up to 4.5 feet (1.4 meters), with a typical length of around 4 feet (1.2 meters).

Are Dumeril's monitors active at night?

No, Varanus dumerilii are diurnal, meaning they are active during the daytime. They are also arboreal, spending most of their time in trees.

How do Dumeril's monitors reproduce?

Varanus dumerilii are oviparous, which means they lay eggs. A single female can produce between 4 and 23 eggs per clutch, and may lay up to three clutches in a year.