Post by Ceratodromeus on Feb 27, 2016 5:33:44 GMT 5
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Lacertilia
Family: Varanidae
Genus: Varanus
Subgenus: (Empagusia)
Species: V.flavescens
Description
The yellow monitor is a stout bodied species, and as the common name may suggest, adults of this species are a dull yellow coloration with bright yellow -- or gold -- crossbands running the lizard's length. Juvenile coloration is typically brighter then that of adults. In some parts of its range, this monitor possesses a red hue that can be found on most of the animals' body. A dark colored stripe can be found behind the lizard's eye, and a light or dark brown coloration can be found on top of the head. They are mid sized varanids, with total body lengths measuring 700-800mm(27.5-31.4in), depending on locality. The tail is around 1.3x the snout-ventral measurement; for example, in a sample of 167 individuals taken from Bangladesh, the average snout-vent length was about 315mm(12.4in), with the average for tail length being 384mm(15.1in){1}. The longest reputedly record for the species was an animal measuring 952mm(37.4in), but a weight for this individual was not taken{2}. Most adult V.flavescens weigh between 500-1000g, but there is a record of a deceased animal measuring 784mm(30in) in total length weighing 1.4kg(3.08lbs){1,2}.
Geographic range and habitat use
Native to the Indian subcontinent(found from Bangladesh to Nepal), Varanus flavescens is very partial to bodies of water -- often being found on the fringes of rice fields, canals, and on riverbanks. In fact Auffenberg(1989) found that the preliminary habitat these animals inhabit is marshland, and during the monsoon season they are frequently found swimming in these waters. They are predominately terrestrial in nature, and are often observed in the undergrowth near the base of trees. They are an understudied species, and throughout most of their range they are poorly known to biologists, but this is not the case with locals who readily identify and distinguish them from other resident varanid species{3}.
Dietary habits
Like other varanids, the yellow monitor is a dietary generalist. Frogs, toads, birds, and their eggs have all been reported in the stomachs of adult animals. Frogs and toads made up the nearly half(49%) of all contents in a sample of 32 wild caught individuals, with masses of amphibian eggs being found in a few individuals{1}. Other foods reported to have been taken by the yellow monitor include rodents, earthworms, crabs, beetles, and unspecified winged insects{4}.
Reproduction
Males and females attain sexual maturity at similar snout-ventral lengths(260mm v 250mm, respectively) at 3-4 years of age. The mating season is thought to occur from June to July, with the female laying a clutch of 6-30eggs(typically closer to 14-16) in burrows or termite mounds. The eggs, which measure 26x32mm(1.02x1.2in) and weigh 10-15g(0.3-0.5oz){1,5}, hatch around October. They are gregarious, living with each other for several months after they hatch feeding on small insects. When they hatch, the young measure anywhere from 145-188mm(5.7-7.4in) in total length, and are very shy.
References
{1} Pianka, Eric R., Dennis King, and Ruth Allen King. Varanoid lizards of the world. Indiana University Press, 2004.
{2} "Status and habitat ecology of the Yellow monitor". Herpetological Conservation and Biology 9.2 (1973): 387-393.
{3} Khatiwada, J. R., and BIPIN CHANDRA Ghimire. "Conservation status of Varanus flavescens in Chitwan, Nepal." Biawak 3.4 (2009): 100-105.
{4} Losos, JONATHAN B., and HARRY W. GREENE. "Ecological and evolutionary implications of diet in monitor lizards." Biological Journal of the Linnean Society 35.4 (1988): 379-407.
{5} Karki, Ajay, Rabindra Bista, and Santosh Humagain. "Distribution, Behavioral Ecology and Present Status of Varanus flavescens (a literature review paper) in Nepal." The Initiation 2.1 (2008): 49-54.
