Himalayan Pit Viper Gloydius himalayanus FACT FILE: Local Name: none (Urdu) Family: CROTALIDAE Genus: Gloydius Status: Rare Warning: This snake is deadly poisonous.    Himalayan Pit Viper (Gloydius himalayanus) Photo Credit: F. Tillack     Species and sub species: Pit vipers are represented by a single species in Pakistan, belonging to genus Gloydius: Himalayan Pit Viper (Gloydius himalayanus) Description and Biology: General characteristics:  Medium-sized snake, with distinct elongated head covered with large symmetrical scales; a distinct pit between eye and nostril; a pair of pre and postoculars, lower longer, separating supralabials from eye; 7 supralabials, posterior two united with temporals to form large post-temporal scales; 9-10 in-fralabials; single pair of genials; body scales strongly keeled, 21 rows at midbody; ventrals 147-175, subcaudals 32-52 divided; anal single.   Dorsum light brown, gray to dark brown. A median series of dark brown blotches, alternating with lateral row of spots. A broad dark band from eye to the angle of mouth. Supralabials light with dark mottling. Ventrum light gray with dark clouding and fine spotting. Snout-vent length 565-572 mm, tail 98-102 mm.     Himalayan Pit Viper (Gloydius himalayanus) Photo Credit: Dr. Muhammad Sharif Khan   Biology: This snake frequents rocky wooded hill sides, where it lives in caverns and crevices among rocks, hibernates in winter from October to April. Basks in bright sunny winter days, habitually sluggish.   Feeds mainly on skinks and other mountain lizards.   Habitat, Distribution and Status: A mountain snake, restricted to an elevation of 1500 m, however, reports exist from Dharmsala Glacier at 5000 m elevation.    The Russell's viper is found from western Himalayas, Sikkim to Chitral, to Northern Pakistan. Recently it has been recorded from Deosai Plain, Baltistan. It has also been reported from Nathia Gali, eastern NWFP and Margalla Hills.   Gloydius himalayanus (O) Map Credit: Dr. Muhammad Sharif Khan     Credits: A Guide to The Snakes of Pakistan, Muhammad Sharif Khan, Edition Chimaira Frankfurt am Main 2002 Dr. Muhammad Sharif Khan, Herpetological Lab Rabwah, Pakistan Nausherwan Ahmed   ©1997-2003 Wildlife of Pakistan-All Rights Reserved.