Red Necked Keelback
The red-necked keelback (Rhabdophis subminiatus) is a colorful snake from South and Southeast Asia, named for the bright red patch on its neck. It looks gentle, but it is both venomous and poisonous, so it should never be handled.
Scientific Classification & Quick Facts
| Common name | Red-necked keelback |
| Scientific name | Rhabdophis subminiatus |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Squamata |
| Family | Colubridae |
| Genus | Rhabdophis |
| Conservation status | Least Concern |
| Type | Reptile (rear-fanged, venomous snake) |
| Diet | Tadpoles, fish, frogs and toads |
| Habitat | Streams, ponds, marshes, rice paddies and damp forests |
| Native range | China, India and Southeast Asia |
| Size | 70-90 cm (28-35 in) long |
| Colours | Olive-green with yellow and red on neck |
| Special feature | Venom fangs at back; toxin from neck glands |
Meet the Red-necked Keelback
This snake belongs to the Colubridae, the largest family of snakes. It is a medium-sized snake: most adults are about 70 to 90 cm (28 to 35 inches) long, and a few grow to around a meter.
For a long time, people thought keelbacks were harmless, much like their relatives the garter snakes. Then several people became seriously ill after being bitten. Scientists studied its venom and found it can stop blood from clotting properly, which can be dangerous. Today it is treated as a medically important snake.
Venomous and Poisonous
The red-necked keelback is a “rear-fanged” snake. Its fangs are at the back of its mouth, not the front. To inject venom, it usually has to hold on and chew, so quick bites often do little harm. Longer bites, especially when people handle the snake, are the dangerous ones.
It also has special glands in the skin of its neck. When threatened, the snake can press these glands against an attacker, releasing a toxic fluid. Its relatives are known to get some of these toxins from the toads they eat. Because it can both inject venom and release poison, it is one of very few snakes that is venomous and poisonous at the same time.
What It Looks Like
The red-necked keelback has a fairly slim body, a head that is wider than its neck and large eyes. Its scales are keeled, meaning each one has a small ridge down the middle. That’s where the name “keelback” comes from.
Adults are usually olive green to grayish green, sometimes with small black and yellow markings. The neck is bright red, often edged with yellow and black, and the head may have yellow on the lips. Young snakes look different: they have less red and a bold black collar across the back of the neck. As they grow, the colors change step by step to the adult pattern.
Behavior
The red-necked keelback is active during the day and is usually calm and shy. It prefers to escape rather than fight.
If it feels threatened, it raises its head and front body off the ground, flattens its neck and arches it toward the threat. This makes it look bigger and shows off the neck glands. It’s a little like a cobra’s hood display, but not as dramatic.
Where It Lives
This snake has a wide range across South and Southeast Asia, including:
- Northeast India, Nepal, Bhutan and Bangladesh
- Myanmar, Thailand, Laos, Cambodia and Vietnam
- Southern China, including Hong Kong and Hainan
- Peninsular Malaysia and parts of Indonesia, such as Sumatra, Java and Borneo
It lives from lowlands up into hill and mountain forests. Like other keelbacks, it is almost always found near fresh water: streams, ponds, marshes, ditches and rice paddies. It also lives in damp forests, grasslands and bushy areas near water, and sometimes rests among low plants.
What It Eats
The red-necked keelback mostly eats animals that live in or near water. Its favorite food is frogs and toads, and it also eats tadpoles and fish. Its body can handle toad toxins that would harm many other animals, which lets it eat prey that other predators avoid.
Can You Keep One as a Pet?
The red-necked keelback is sometimes seen in the pet trade, and it can seem calm when handled. But because its bite can cause serious bleeding problems and its neck glands release toxins, it is not a safe pet. It should only be kept by trained professionals, such as zoo keepers. If you see one in the wild, enjoy it from a safe distance and never try to pick it up.
Fun Facts
- The word “keelback” describes the ridged scales that run along the snake’s back.
- Red-necked keelbacks lay eggs, usually in damp places near water.
- Its bright neck colors are a warning signal to predators: “Stay away, I’m toxic!”
Red-necked keelback FAQs
Is the red-necked keelback dangerous?
It was once thought to be harmless, but it is now known to be venomous. It has fangs at the back of its mouth and must hold on or chew to inject venom. It also oozes toxins from glands in its neck.
What do red-necked keelbacks eat?
They eat water animals such as tadpoles, fish and frogs. They also eat toxic cane toads, and are resistant to the toads’ poison.
Where do red-necked keelbacks live?
They live in China, India and Southeast Asia, from lowlands up to about 1,800 metres. They stay near water, like streams, ponds, marshes and rice paddies.
How big are red-necked keelbacks?
They are usually 70 to 90 centimetres (28 to 35 inches) long and slender.
Can a red-necked keelback spread its neck like a cobra?
It can raise its head and flatten its neck to look bigger, about 4 to 5 inches off the ground, but not as dramatically as a cobra.
Randi Jones is the owner and founder of the Nature Gift Store, an online retailer specializing in nature-themed gifts, educational science projects, live animal nature kits and real butterfly artwork. A biology graduate who fell in love with insects, she founded the company in 2001 to make active learning about nature fun, accessible and engaging for children and adults. Her store offers real butterfly frames, home and garden decor and educational live animal kits, including ant farms, worm farms, tadpoles, ladybugs and hermit crabs, and she runs a bug museum in Washington featuring live animals like Eddie the Iguana alongside other reptiles and insects.
