Yellow monitor

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Yellow monitor
Varanus flavescens1.jpg

Yellow monitor ( Varanus flavescens )

Systematics
without rank: Toxicofera
without rank: Sneaky (Anguimorpha)
Family : Varanidae
Genre : Monitor lizards ( varanus )
Subgenus : Empagusia
Type : Yellow monitor
Scientific name
Varanus flavescens
( Hardwicke & Gray , 1827)

The yellow monitor ( Varanus flavescens ) is a species of the scale creeping animals (Squamata) from the genus of monitor lizards ( Varanus ).

features

The yellow monitor is a medium-sized monitor that can reach a maximum total length of up to about 90 cm. The tail length is 1.3 times the head-trunk length and is therefore rather short. An average length of 70 cm was found in 167 specimens caught in India. The weight of fully grown yellow monitors is usually between 500 g and 1 kg. There is very little gender dimorphism in terms of size . The head is short and high, and the muzzle is broad. The nostrils are slit-shaped and are closer to the tip of the snout than to the eye. The trunk is stocky and covered with comparatively large and strongly keeled scales. The toes are quite short, especially on the back feet. The laterally compressed tail has a double keel made of scales on top.

The color of the species is quite variable. The top of the body is dark to light olive brown or reddish. The back is marked with cross bands of more or less fused and often dark-edged yellow spots. A black network drawing can also be used. The belly is yellowish with indistinct transverse bands. A black stripe begins behind the eye and extends over the temple (temporal stripe). Adult animals are particularly beautifully colored during the mating season (monsoon season), such a seasonal color change is unusual for monitor lizards. Young animals are drawn in black and yellow.

distribution and habitat

The yellow monitor lives in southern Asia, from south of the Himalayas to East Pakistan, northern India, Nepal and Bangladesh. The species lives in particular in the areas around the Indus, Ganges, Brahmaputra, Brahmani and Mahanadi rivers. The preferred habitat is marshland, the yellow monitor also inhabits river banks, canals and rice fields.

Way of life

Like all monitor lizards, the yellow monitor is a diurnal loner. During the night, yellow monitor lizards retreat into burrows they dug themselves. Yellow monitor lizards are practically inactive during the dry season between November and February, which they also survive in their burrows. In November the monitor lizards eat the largest possible fat reserves, as the energy-intensive reproductive period (e.g. yolk formation ) is then also over. Yellow monitor lizards are predominantly ground dwellers. Even if they climb occasionally, their short toes limit them. During the monsoon season from June to October, the animals can also often be found in the water.

nutrition

The yellow monitor actively searches for prey by licking its wings and probably hunts it both in the water and on land. Yellow monitors eat frogs, amphibian spawn, reptile eggs, birds, bird eggs, insects and rodents, and occasionally mollusks. The main part of the food is made up of frogs.

Reproduction

Both males and females become sexually mature at around 3-4 years of age. The males then have a head-torso length of about 26 cm, the females measure about 25 cm head-torso length at this age. The mating season falls in June and July, so mating takes place in the early rainy season. The females then lay their eggs weighing around 10 g until October. Only one clutch of 4–30 eggs is produced per year (⌀ 16). To lay eggs, the female creates a cave, which she digs in elevated terrain to avoid flooding. The young hatch in India in March, shortly before the start of the next rainy season.

It is noticeable that yellow monitor lizards show only a few scratches or even bite wounds, so that pronounced competitive behavior of the males (e.g. comment fights ) is unlikely. The conspicuous coloration at the mating season may play a role, especially since it correlates with spermatogenesis , oogenesis and the onset of sexual maturity. Visser (2004) suspects that these processes are controlled by hormones.

Life expectancy

Yellow monitor lizards can live up to 10 years in captivity.

Web links

Commons : Yellow monitor ( Varanus flavescens )  - Collection of images, videos and audio files

swell

  1. a b c d e f g h G. Visser (2004): Varanus flavescens . In: ER Pianka & DR King (2004): Varanoid Lizards of the World : 179-183. Indiana University Press, Bloomington & Indianapolis. ISBN 0253343666
  2. a b D. Bennett (1996): Warane der Welt. World of monitor lizards : 165–167. Edition Chimaira, Frankfurt am Main. ISBN 3-930612-05-4