| 1 | Eastern stripe-bellied sand snake |
Maximum length: 140cm.
Around the world, snakes have various defensive tactics, from the usual venom and aggression, to faking death and mimicking more dangerous snakes. However, another chunk have evolved the ability to cleanly detach their tail, one being the eastern-striped bellied sand racer (Psammophis orientalis).
This species measures up to 1.4 metres, and lives in South Africa, Mozambique and Zimbabwe, favouring moist savannahs and sparse woods. They’re an active species which is always slithering around and investigating nooks and crannies curiously.
Unfortunately, this means that they’re highly visible to bird predators. When eastern stripe-bellied racers are scooped up in steely bird talons, they have the option to bite down painfully, thrash wildly, or release a foul snake smell. But the last resort is to sever their own tail, so that they can escape the bird’s grip. Psammophis orientalis achieves this with a sudden twist on its axis, while still securely gripped.
This normally removes the latter half of the sand racer’s tail, which will be missing for the rest of their lives, but gives them a ticket to safety that the bird isn’t expecting. A study on this species found the rate of missing tails in the wild to be 45.9%. Several other family members have this ability too, including the hissing sand snake of Egypt (P. sibilans) and Karoo sand snake of Namibia (P. notostictus).
| 2 | Yellow belly snake |
Maximum length: 80cm.
The yellow belly snake (Coniophanes fissidens) is a fairly mysterious species which resides in the humid forests of southern Mexico and central America, sometimes near mango trees. After 160 years, its exact diet breakdown is still poorly mapped, with rainbow ameivas and earthworms confirmed to be included.
However, one thing European explorers noticed from the getgo was that a large proportion had tails missing. Some were long, swishy and majestic, but others were mere stumps. More recently, a 1992 survey found that 60% of yellow belly snakes had their tails missing.
Yellow-belly snakes have decent protection in their forests, thanks to effective camouflage and a vicious bite. But if these fail, releasing their tail is their final barrier of defence. Like others, this barely bleeds, and continues to twitch for a while. Yellow belly snakes live on branches, and their favourite place to rest is between two massive overlapping rainforest leaves, but there’s always a handful of birds which can see through this disguise.
| 3 | Red-headed glasstail |
Maximum length: 69cm.
The red-headed glasstail (Urotheca fulviceps) is a common tail detacher. It lives in the forests of Panama, and has a mild venom which is too weak to take down birds, even if it penetrated their feathers. If in mortal peril, seconds from death, the red-headed glasstail snake will cleanly detach its tail. The bird’s grip is loosened, and escape is suddenly possible.
This also affords them the precious gift of time, a few seconds where the bird is utterly confused by the tail still in its grasp, and fails to notice that its real prize is disappearing into the bushes. In the jungle, the gap between survival and death can be measured in mere milliseconds.
That said, this trick is mostly useless against fellow snakes. One top snake eater in Panama’ forests is the Central American coral snake, AKA Micrurus nigrocinctus. This species has a powerful neurotoxic venom, and after one sudden bite, the toxins would already be flowing through the glasstail’s body. Even if they broke free, they would fall into paralysis moments later.
| 4 | Olive forest racer |
Maximum length: 118.3cm.
This frog-eating species is found in Ecuadorian and Peruvian forests, including trails frequented by humans. Olive forest racers (Dendrophidion dendrophis) measure up to 118.3cm, and primarily stick to the ground, climbing trees occasionally, and investigating small forest pools where their humming frog prey heavily congregate.
Olive forest racers lack any venom, and have been forced to evolve alternative survival strategies, one of which is severing their own tail, as a greedy bird grabs hold. Like all snakes, the olive forest racer’s tail never grows back, leaving them stumpy, yet happily alive to tell the tail.
This species also has strong camouflage against the forest floor, but a snake’s tail tip is pretty far from its head, and it’s hard to control it at all times. There’s always going to be times when their tail is poking out unexpectedly, or it’s too late to dash to a shelter, and a cunning hawk on a nearby branch cocks its head up with interest. In these situations, the olive forest racer has one final card to play.
| 5 | Olive marsh snake |
Maximum length: 60cm.
The olive marsh snake (Natriciteres olivacea) dwells in the waterways of central Africa, weaving between lily pads amid rotting swamp juice. They’re assumed to prey mainly on frogs, which they acquire through an extremely fast burst of swimming. With less tree canopies protecting them, olive marsh snakes are easy pickings for bird predators divebombing from the sky, particularly heron and storks.
If there’s no other option, then the olive marsh snake will separate its tail without hesitation. Members of the Natriciteres group have such fragile tails that they often break off in scientists’ hands without them doing anything. According to a 1987 study, 43.6% of olive marsh snakes observed had tails missing.
Olive marsh snakes are fairly common, ranging from Ethiopia in the north to Botswana in the south. They’re not cowardly, and can also bite their bird enemies, but sometimes, the angles are plain wrong. If a bird seizes them by the tail instantly, then it might be impossible to bend around fully and sink their teeth in. That’s why severing their own tail is often the costly yet logical option.
| 6 | Columbian longtail snake |
Maximum length: 70cm.
The Colombian longtail snake (Enuliophis sclateri) is a species of low-lying forests at up to 1650 metres in altitude. As well as Colombia, they’re found in Panama, Costa Rica, Nicaragua, and eastern Honduras.
This species lacks any venom, and must resort to subtler methods instead. One tactic is playing dead, by flipping over onto their back and revealing a bright white underside, and they’re also able to detach their tail instantaneously. This is deployed only in serious emergencies, like when their tail is being directly gripped.
As with the eastern ribbon snake, this tail keeps wriggling for several seconds after it’s been detached. A bird might be completely fooled by the deception, flying off with the tail in its talons, triumphantly carrying its hard-earned meal. Only when they bite down to feel a hard crunch would they realise that they’ve been fooled, with just thin scraps of meat available to scrape out. Meanwhile, more cunning birds might not be fooled at all, instantly sensing that they’re not carrying a fully fledged snake meal.
| 7 | Rio tropical racer |
Maximum length: 197cm.
The Rio tropical racer (Palusophis bifossatus) is one of the most frequent tail detachers, with one survey estimating that 46-52% have the lower portions missing. They have plenty of tail to start with, as this is a long and whippy species which can reach almost 2 metres.
The Rio tropical racer is a widespread species which sticks to pristine forests, appearing in Brazil, Paraguay, Bolivia and northern Argentina. Their hunting style involves rapid charging, at natural breakneck speeds, followed by an accurate pounce. Their defensive strategy involves frenzied biting, fleeing at high speeds, and of course severing their own tail. This tail can detach so suddenly that it takes birds by surprise, allowing them to slither to freedom.
One unanswered question is how detaching a tail feels, whether it’s agonisingly painful or the equivalent of cutting a fingernail. We may never know, as snakes aren’t able to tell us.
Likewise, it’s a mystery as to whether snakes can consciously control this ability. The connective scales in their tails might be naturally fragile, or it might be automatic, as an emergency instinct in the snake’s brain activates after danger signals reach critical levels.
| 8 | Guatemala neckband snake |
Maximum length: 92cm.
Most snakes would rather not lose their tail, but if the alternative is a frenzied burrowing owl, then there is no alternative. The Guatemala neckband snake (Scaphiodontophis annulatus) is a tail detacher from Central America, which lives in pristine forests with dense undergrowth. It’s greatly feared by brown forest skinks, its main prey, yet the Guatemala neckband snake also has mortal enemies of its own.
This species has so much fear for eagles and hawks that it will snap off its own precious tail to avoid their clutches. It does so cleanly and efficiently. Not only do Guatemala neckband snakes lose little blood, but they suffer no shock to their system, no stunned expression – they just slither off without interruption.
A study found that 70% of Guatemala neckband snakes in one forest had their tails missing. Exactly how many millions of years ago this trick began is unknown. The more logical thing would have been for snakes to evolve an extremely spiky tail, similarly to a hedgehog, which would be extremely painful for birds to touch. Somehow though, no snake has ever managed this. Perhaps this is a future evolution to watch out for in snakes.
| 9 | Eastern ribbon snake |
Maximum length: 104cm.
The eastern ribbon snake inhabits the northeastern USA, including Ohio and Pennsylvania. They stick closely to water bodies, particularly small streams and lakes in the grassy countryside. They possess an extremely mild venom, and prey largely on small fish.
This snake particularly loves to climb riverside trees to bask in the sunlight, giving them a miraculous ability to escape flash floods. Less positively, this also makes them easy pickings for watchful bird predators. Eastern ribbon snakes can detach their tail, and do so far more commonly than their garter snake cousins.
One cool feature is that the stump barely bleeds. It might leave a small speckle of blood, but not the spurt from a normal animal. The wound seals itself instantly, so that the eastern ribbon snake can carry on uninterrupted. This hints that the power evolved a relatively long time ago, if it’s become so refined.
There are costs though. A study on their close garter snake relatives found that those with missing tails were significantly poorer swimmers. Eastern ribbon snakes eat a diet of over 90% amphibians, according to one study from 1952.
| 10 | Checkered keelback |
Maximum length: at least 140cm.
The checkered keelback (Fowlea piscator) is a mildly venomous snake which dwells in the marshes of India and Bangladesh, leading a humble lifestyle and posing no threat to humanity. This species can be incredibly abundant, as some scientists believe them to be India’s most common snake species by headcount.
Checkered keelbacks are experts at ducking below the surface, hiding in the murky depths, but their reactions aren’t always fast enough. A costly, yet often unavoidable backup is shedding their own tail. This is followed by a rapid dash to safety, leaving the stunned bird thwarted in its apparent moment of triumph.
The big downside to this power is that snakes can only use it once. Once their tail has snapped off, that’s it, it won’t regrow, and that form of defence will be closed off.
The next time a bird swoops in with its talons outstretched, the checkered keelback’s chances of survival will be far smaller. They’ll have to hone their skills at thrashing wildly, or biting instead. It’s a harsh world that the checkered keelback lives in, but they compensate with a gigantic egg clutch of up to 100. Another of their backup skills is playing dead.