Ridley’s Racer – Cave Snake

Othriophis taeniurus ridleyi (Ridley’s Racer)

Length: up to 2.5 meters. I have found a couple of dozen of these snakes over the years. The biggest one was just about 2.25 meters long.

Range: Chumpon, Thailand, south to the border of Thailand-Malaysia

Habitat: Usually caves, though at times found outside caves. Recently I found several of them in a bungalow at a nature resort and an empty wooden cabin on a rubber plantation. Then someone wrote me to ID one that was climbing around the limestone cliffs in Krabi.

I’ve seen them cross a country road in the middle of a hot and sunny day. I’ve found them in ditches in the daylight hours as well.

These are stunning snakes with a simple pattern, but beautiful to look at!

Active Time? The snake is mainly nocturnal. They are active during the day after heavy rainfall, or inside caves for the most part, but I have seen them active during daylight hours as well.

Food: Bats, birds, and maybe even rats if they happened to be on the ground. They are known to be able to hang from a cave wall and catch bats as they fly by – out of the air!

Defensive Behavior: These Thailand snakes are calm and move slowly unless provoked substantially.

Venom Toxicity: None. Member of rat snake group – so their saliva probably contains venom, but they have no venom-injecting fangs in the front or rear. They have rows of teeth in the upper jaw, but they are very small – less than 1/4th inch long.

Offspring: Nothing known – still updating this article. I have never had a chance to see juveniles in the wild or captivity. Probably the same pattern as adults.

Notes: These are often found in Thailand caves, they are excellent wall climbers. A Buddhist monk walked me through some pitch-black caves at a temple with a cave in Southern Thailand and showed me this amazingly colored Ridley’s Racer pictured above. This non-venomous snake, part of the rat snake family was calm and let me take video with the camera just 12 inches from her head. Ridley racer snakes hang on cave walls and snatch flying bats out of the air.

Classification: T. ridleyi

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Colubrinae
Genus: Othriophis
Species: taeniurus ridleyi

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  1. a snake in the garden……..length-50 cms….diam–1-2cms
    looked all one colour grey to black…
    what was it I am in Koh Samui Thailand

    1. Hi Peter… I’m not that good. You’ll have to get a photo. At half a meter it could be juvenile and the snakes change in appearance as they develop. Could be MANY different types with that description.

  2. There was a snake on my front porch the other day. I was out of country on business; my wife thought it was a cobra because it reared its head about a foot from the ground and had a small hood. The snake was cornered by my huskies and then removed by my staff; my wife said that the snake went for one of the huskies but i think if it had been a cobra the husky would have been in trouble. it was about 1.5m in length and “black” (according to a thai which basically means any dark colour)this snake had a barely visibly green line from head to tail. My staff said these snakes are quite common in the moo baan (Muang Ake project, Pathum Thani) We are next to a small lake that contains several water monitors. I am curious to know if you have an idea of what this snake was and also if there are cobras or Kings in this area? as it would present considerable danger to the dogs. many thanks.


  3. I have seen Ridleys racers several times in caves in northern Thailand – Tham Tub Tao, 40 km north of Chiang Dao, Chiang Mai province. Very definitely this snake – about 1 – 2 metres. I am a Biology teacher!
    Thought you might be interested that they are NOT only found south of Chumphon.

    1. Possible, the ranges in books are not set in stone. There is another rat snake that is in the far north that resembles the Ridley’s racer. I don’t remember where I saw the range info. Cheers

      1. Last month I went to Mae Lana Cave in the extreme north-west of Thailand, and saw what I’m pretty sure was a Ridley’s racer, well inside the cave in complete darkness. I have some photos (not very good, taken with my phone in a waterproof bag) – if you want to email me I could send them to you.

        1. Yes, email to me – I always like to get photos! Cheers David

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