Checkered Keelback (non-venomous)

Description: A medium- to large-sized water snake, averaging 75 cm in total length, but occasionally reaching 135 cm. Ground colour grey, brown or olive above, with many black dots arranged in a checkered pattern. In manyspecimens this pattern extends all the way to tail, while in others it gradually fades about half-way down the body. Some specimens have vivid red or orange spots on lower sides. Scales moderately keeled. Two black streaks behind each eye, sometimes with a patch of yellow between them, especially in juveniles. A black chevron marking on neck. A short yellowish streak sometimes present on top of head. Ventrals dirty white, with black border to each side.

Habits and habitat: Prefers lowland ponds, streams and ditches in cultivated fields; is scarce around large fish ponds, and absent from mangrove swamps and mountain streams. Occasionally found in upland basins (Po Lin Monastery grounds). A very good swimmer and diver. Can remain submerged for up to 20 minutes before surfacing. Is both diurnal and nocturnal. When caught, flattens and bends the neck in menacing posture, then strikes and bites viciously. Was more abundant in the early 1980s than at present. Although still common to abundant in some areas, has decreased in other localities due to destruction of suitable habitat by urban development, as well as abandonment of cultivated fields and subsequent invasion of grasses. Does well in captivity.

Diet: Feeds on fish, frogs, tadpoles, and rarely on small toads.

Reproduction: Breeds during the warm part of the year, particularly in March-April. Normally lays 20-40 eggs, but the record is 88. Hatchlings 15-20 cm long; and can be seem from July to September.

Distribution: Occurs throughout the New Territories and on all major islands. Found in southern China including Taiwan, South and Southeast Asia.

Diagnostic features: Olive-brown colour; with black-checkered spotting; two oblique black streaks from eye to upper labials; keeled dorsal scales; ventrals edged in black.