16-4-2024 PANNA TIGER RESERVE, INDIA - BENGAL MONITOR (Varanus bengalensis)

The Bengal monitor (Varanus bengalensis) is a large terrestrial monitor lizard. Young monitors, however, may be more arboreal, but adults mainly hunt on the ground. Although large Bengal monitors have few predators apart from humans who hunt them for meat, younger individuals are hunted by many predators.

Young Bengal monitors are more colorful than adults. Young have a series of dark crossbars on the neck, throat, and back. The belly is white, banded with dark crossbars, and is spotted with grey or yellow (particularly in the eastern part of the range). On the dorsal surface of young monitors, there are a series of yellow spots with dark transverse bars connecting them. As they mature, the ground color becomes light brown or grey, and dark spots give them a speckled appearance. Bengal monitors have external nostril openings (nares) that are slit-like and oriented near horizontally and positioned between the eye and the tip of the snout. The nares can be closed at will, especially to keep away debris or water. The scales of the skin are rougher in patches and on the sides, they have minute pits, especially well distributed in males. 

These scales with micropores have glandular structures in the underlying dermal tissue and produce a secretion that may be a pheromone-like substance. Like other monitors, Bengal monitors have a forked tongue similar to snakes. The function is mainly sensory and is not very involved in the transport of food down the throat. Bengal monitors have fat deposits in the tail and body that serve them in conditions when prey are not easily available. The lungs have spongy tissue, unlike the sacs of other saurians. This allows for a greater rate of gas exchange and allows a faster metabolic rate and higher activity levels. Like all monitors, they have subpleurodont teeth, meaning the teeth are fused to the inside of the jaw bones. While monitor lizards are venomous, there are no reports of the effects of venom in Bengal monitors other than a very controversial case report of fatal renal failure as a result of envenomation from this species.