Protobothrops kaulbacki, commonly known as Kaulback's lance-headed pitviper or Kaulback's lance-headed pit viper,[1] is a venomous pit viper species endemic to Asia. There are no subspecies that are recognized as being valid.
The specific name, kaulbacki, is in honor of British explorer Ronald Kaulback.[2] [3] [4]
Adult males of P. kaulbacki may attain a total length of 134cm (53inches), which includes a tail 22.5cm (08.9inches) long. Females may grow longer: maximum total length 141cm (56inches), tail 23cm (09inches). Dorsally, it is green, with a vertebral series of dark angular spots, which may be joined to form a zigzag stripe. The top of the head is black with yellow stripes. Ventrally, except for the whitish throat area, it is gray with large squarish or crescent-shaped yellow spots.[5] Scalation includes 25 rows of dorsal scales at midbody, 201–212 ventral scales, 66–78 subcaudal scales, and 8 supralabial scales of which the third is the largest.[1]
P. kaulbacki had originally been known only from the type locality, which is "Pangnamdim, north of the Triangle, Upper Burma" (Myanmar). In 2005 it was reported also from Tibet (China).[6] It also occurs in Arunachal Pradesh (NE India).
The preferred natural habitats of P. kaulbacki are forest, shrubland, and grassland, at altitudes of .
P. kaulbacki is oviparous. The adult female lays a clutch of 6–32 eggs in a hole in the ground, and then remains with the eggs to guard them. Eggs measure 48–53 mm x 26–27 mm (about 2 in x 1 in). Each hatchling is 26–27 cm (about 10½ inches) in total length.[5]
P. kaulbacki is terrestrial and partly arboreal.[7]