Types of keelbacks

Fowlea is a genus of colubrid snakes in the family Colubridae, the largest and most diverse snake family. Its members are commonly called keelbacks, a name that points to the raised ridge, or keel, running down the center of most of their dorsal scales. This keeling gives the body a slightly rough, matte texture rather than a smooth shine. Several species now placed in Fowlea were long grouped under the genus Xenochrophis, and the two names are still used interchangeably in older field guides and databases.

The genus is centered on South and Southeast Asia. Members range across India, Sri Lanka, Bangladesh, Myanmar, Thailand, southern China, and the islands of Indonesia and the Philippines, with the wide-ranging chequered keelback reaching across much of that area. These are water snakes in habit. They live in and around freshwater: rice paddies, ponds, irrigation canals, slow rivers, marshes, and roadside ditches, including disturbed and agricultural land near people. They are strong swimmers and rarely stray far from water.

Recognizing a Fowlea keelback comes down to a combination of build, scale texture, and setting rather than one single mark. They are slender to moderately built snakes of small to medium size, generally a foot and a half to a little over three feet long, with keeled scales and large eyes set high on the head, an adaptation for a life spent partly submerged. Patterns vary by species and include checkerboard blotching, rows of spots, or fine speckling over olive, brown, or greenish ground colors. Because color and pattern overlap heavily between species and with unrelated water snakes, exact identification is best confirmed by a regional expert.

Fowlea keelbacks are not considered dangerous to humans. They are non-venomous in the medical sense and have no front fangs and no potent venom delivery. When cornered they put on a memorable threat display: flattening the neck and forebody, raising up, and striking, behavior that can resemble a cobra and leads to many harmless keelbacks being killed out of fear. A bite from one of these snakes may cause minor local bleeding or irritation but is not a medical emergency. Even so, no wild snake should be handled. Misidentification is the real risk, since dangerous species can share the same waterside habitat. If anyone is bitten by a snake they cannot positively identify, treat it seriously, stay calm, keep the limb still, and seek emergency care. In the United States contact Poison Control at 1-800-222-1222, and elsewhere call local emergency services.

Ecologically these snakes are aquatic hunters. Their diet is dominated by fish and amphibians such as frogs, tadpoles, and toads, which they pursue actively in shallow water. Like most colubrids in the genus, they are egg-laying, with females depositing clutches of eggs rather than giving live birth. They are largely diurnal to crepuscular and play a useful role in wetland and rice-field food webs, both as predators of fish and frogs and as prey for birds, larger snakes, and mammals. Their tolerance of human-modified wetlands makes them among the more frequently encountered water snakes across their range.